﻿A review of the genus Laeocathaica Möllendorff, 1899 (Gastropoda, Pulmonata, Camaenidae)

﻿Abstract In this paper an overview of the Laeocathaica species is provided, and the intraspecific variability of several Laeocathaica species demonstrated on multiple shells. Laeocathaicahisanoi Páll-Gergely, sp. nov. and L.minwui Páll-Gergely, sp. nov. are described based on specimens found in museum collections. Five new synonyms are recognized: L.prionotropisalbocincta Möllendorff, 1899 is a new synonym of L.prionotropis Möllendorff, 1899, L.stenochone Möllendorff, 1899 is a new synonym of Laeocathaicacarinifera (H. Adams, 1870). Laeocathaicadistinguenda Möllendorff, 1899, L.tropidorhaphe Möllendorff, 1899, and L.dangchangensis Chen & Zhang, 2004 are moved to the synonymy of Laeocathaicaamdoana Möllendorff, 1899. Furthermore, photos of paratypes of Cathaicabizonalis Chen & Zhang, 2004 are published for the first time.


Introduction
The genus Laeocathaica Möllendorff, 1899 consists of approximately 20 species, and inhabits west China. Most of the species assigned to this genus were reported from the southern part of Gansu Province and the neighbouring Sichuan. A single species, L. filippina (Heude, 1882) is known from Hubei Province, more than 500 km southeast from southern Gansu. The monophyly of this genus is questionable for several reasons. First, Laeocathaica is defined by the sinistral shell coiling, whereas species with dextral shells of otherwise similar appearance (large, depressed shells with white base colour and brownish spiral bands) are included in other genera such as Cathaica Möllendorff, 1884, Bradybaena Beck, 1837, and Euhadra Pilsbry, 1890(Chen and Zhang 2004. The type species of the latter is Helix peliomphala L. Pfeiffer, 1850 from Japan, which makes it questionable that the same large-bodied land snail genus could inhabit such a vast area covering ca. 3500 km. Moreover, species similar to Laeocathaica species (e.g., Bradybaena haplozona Möllendorff, 1899) have been classified in genera different from Laeocathaica (Möllendorff 1899;Chen and Zhang 2004). Second, the genus Laeocathaica as understood by Möllendorff (1899) and Chen and Zhang (2004) is variable in terms of shells characters. Some are large, with a white base colour, keeled or rounded body whorl, and without apertural barriers, others are keeled with apertural barriers, and some are small, transparent, and also possess apertural teeth. The genital anatomy is known in a handful of species only: L. prionotropis (see Chen and Zhang 2004), L. polytyla (see Schileyko 2004) and L. filippina (see Wu 2004), providing little basis of our understanding of the systematics of Laeocathaica and related genera.
In this paper we provide an overview of the genus Laeocathaica after consulting all available types and newly collected samples. We provide precise localities for most species, and photographs of multiple shells showing intraspecific variability for the first time in this genus.

Materials and methods
We counted the whorls of adult shells according to Kerney and Cameron (1979). Of the newly collected specimens and the ones deposited in the Senckenberg Museum, 10-20 photographs were taken of each shell using Canon EOS 6D camera and a Canon Macro Lens EF 100 mm 1: 2.8 and merged to create a single image using Photoshop. Shells deposited in other museums were photographed by the respective museum staff.  contains several probably conspecific juvenile specimens in ethanol.
6. Another jar labelled as paratypes of Laeocathaica carinalis (IZCAS TM 097588-097602) contained several dry adult shells of Cathaica bizonalis (two of them figured in this work, see Fig. 1). This clearly shows that shells of the above taxa have been confused even before the publication. As a result, not only were the different samples mixed up with the labels in the collection, but also in the original descriptions.
Based on Chen and Zhang (2004) and the examination of the specimens deposited in IZCAS, we conclude the following: 1. Fig. 219 in Chen and Zhang (2004) shows the holotype of Laeocathaica carinalis Chen & Zhang, 2004 instead of Cathaica bizonalis.
3. A holotype was designated in the original description of Cathaica bizonalis, so a lectotype cannot be chosen later. The holotype cannot be located because there is no photograph in the original description, and because the paratypes are of similar size (i.e., the given measurements of the holotype are insufficient to recognize the shell). So, we treat it as lost (perhaps in the lot of paratypes). Since all the paratypes belong to one single species, and are consistent with the original description, we know what the authors intended by the taxon, so designation of a neotype is not needed.
Remarks. Laeocathaica amdoana was described from Pass Ho-Dshi-Gou bei Mugua-tshi (the exact locality could not be located on the map) near Wenxian at the border with Sichuan province, and characterised by a domed, brown, dorsal side with a relatively broad, sharp, distinctly bordering, white band of the keel. We did not find shells identical to typical Laeocathaica amdoana, but have found similar ones that can be identified as conspecific (Figs 3C,D,4).
Laeocathaica distinguenda is represented in the Senckenberg Museum by several samples. Strangely, the lectotype is the most "untypical" among the lots labelled as L. distinguenda due to its pale caramel colour, the blurry border of light and dark stripes, and the rounded body whorl. Our samples from the vicinity of Wenxian  Laeocathaica tropidorhaphe was described from the north (Tanchang and its vicinity), and is characterised by a large, keeled shell with a flat dorsal side and a thick brown spiral band. The northernmost populations we collected (samples 2016/87, 2016/88, 2016/89, 2016/91, 2016/95) agree with the types of L. tropidorhaphe in size, shape, and colouration, but their spire height is variable. However, some shells from much further south are also similar (i.e., samples 2016/74, 2016/75, see Fig. 4). The characteristic colouration of L. tropidorhaphe (brown dorsal side with slender white band on the keel) is also not unique to the northern L. tropidorhaphe populations, but can be found in more southern populations as well (compare Fig. 4a with Fig. 7).
Overall, there is a continuous variation across most of the historical and newly collected samples in terms of shape of dorsal side, shape of body whorl, size, colour, and sculpture (see Figs 3B, C; 6B, C). Laeocathaica amdoana and the lectotype of L. distinguenda (but not the paralectotypes!) seem to be slightly out of the morphological continuum, but not to a degree that a species-level distinction should be applied.
Colouration can be extremely variable even within a single population (see Fig. 4). Therefore, colour is of minor importance in species distinction within this group of Laeocathaica. It is a general trend that towards the southeastern part of the distribution of these "species", the peripheral keel disappears and the body whorl becomes rounded.
Because of the aforementioned reasons, and until anatomical and DNA sequence data become available, we do not find the names L. distinguenda and L. tropidorhaphe meaningful, and so we provisionally synonymise them with L. amdoana. Table 1 summarises the key traits that are variable across and within newly collected populations.
Laeocathaica dangchangensis Chen & Zhang, 2004 is also a junior synonym of L. amdoana, because it shows the same characteristic conchological features (large shell size, acute, white keel, almost flat dorsal side) as L. tropidorhaphe. Moreover, its type locality (Shawan town, Dangshang county (34°0'N, 104°3'E), Gansu Province, China) is situated close to the known sites of L. tropidorhaphe, whose two closest populations are situated at ca. 31 km and 35 km from the type locality of L. dangchangensis.
According to the original description of Laeocathaica dangchangensis, the holotype has a shell width of 27.22 mm. However, the shell labelled as the holotype is 23 mm wide. Moreover, the number 6 is written on that specimen's dorsal side, whereas "Holotype: Sp8" is written on the label. We have not found any shells bearing the number 8. Consequently, the shell labelled as the holotype is a paratype, and the real holotype is probably one of the specimens labelled as paratypes, or lost. Type material. The shell we examined (IZCAS TM 097578) is exactly the same as the one figured by Chen and Zhang (2004: fig. 219) as the holotype of Cathaica bizonalis Chen & Zhang, 2004. Therefore, we understand this situation as a confusion of specimens and photographs before publication, and consider the figured shell (IZCAS TM 097578, Fig. 9) as the holotype. See also under Cathaica bizonalis Chen & Zhang, 2004.  Description. Shell sinistral, depressed, strongly keeled, dorsal side with flat, scalariform whorls; ventral side widely conical; dorsal side chocolate brown, ornamented with a white keel on all whorls; ventral side primarily white, below the white keel there is a chocolate brown belt, white part ornamented with greyish radial stripes that sometimes reach the umbilicus, but sometimes thin and stop before umbilicus; umbilicus inside with a chocolate-brown and a white belt; entire shell consists of 7.25-7.75 whorls; protoconch consists of 1.5-1.75 whorls, brownish, seemingly smooth, extremely finely granulose, rather matte, slightly protruding above first whorls of teleoconch; white keels of every whorl slightly elevated from dorsal surface, but dorsal surface flat with usually the last one being scalariform; dorsal side with fine, irregular wrinkles and between the main wrinkles there are very fine radial lines; ventral surface with less prominent wrinkles; umbilicus rather narrow, funnel-shaped, shows all whorls; periumbilical keel absent; aperture oblique to shell axis, semilunar, with pointed incision at the keel; peristome expanded and slightly thickened, but not reflexed; palatal swelling whitish, with a low, blunt basal tooth; parietal callus practically absent, in some old specimens with translucent calcareous layer.

Laeocathaica carinalis Chen & Zhang, 2004
Measurements (in mm): D: 18.6-22.9; H: 6.8-9.8 (n = 13, newly collected shells from multiple samples).  Differential diagnosis. The most similar species is L. pewzowi, which is smaller, paler in colour, has a wider umbilicus, a more domed (and not scalariform) dorsal side, stronger radial sculpture, and a more oblique aperture with a more pointed basal tooth. Furthermore, there is a second broken belt between the main belt and the umbilicus in L. pewzowi, which is not present in any specimens of this species. Laeocathaica potanini has a more scalariform, uniformly light brown shell, and the basal tooth (when present) is situated closer to the columella than in L. carinalis. Laeocathaica amdoana is also similar in colouration, but it is larger, has a blunter keel, a weaker sculpture, and its whorls are never scalariform.
Distribution. Most precise locality data are from the rocky area along the Baishui River, whereas one sample was collected on the bank of the Yangtang River (Fig. 11). The type locality is situated ca. 50 km west in a straight line.
Remarks. We here provide a redescription, an updated differential diagnosis, and notes on the differences between different populations (Table 2).     Distribution. The original description Helix christinae var. carinifera was published together with that of the nominotypical form, without any specification of a type locality. However, on one of the boxes of var. carinifera in the NHM, the locality Woushan (probably Wushan, Chongqing at 31°5'N, 109°53'E) was mentioned. The type locality of Helix subsimilis is Moupin (Baoxing, at 30°22'N, 102°49'E) in Tibet. Furthermore, Wu (2004) dissected Laeocathaica subsimilis specimens collected at Nanchong, Sichuan. All precise locality data are known from southern Gansu and from the centre of Chengdu city in Sichuan (probably introduced?). Therefore, it is possible that L. carinifera is a widespread species, or the locality data from 250-450 km from southern Gansu are the results of imprecise labelling. On the map (Fig. 11) we only indicate the newly reported samples from southern Gansu. Remarks. Adams (1870) described Helix christinae and Helix christinae var. carinifera. According to the original description, var. carinifera differs from the nominotypical form by the smaller shell, the more acute keel, and the narrower umbilicus. We found a sample labelled Helix christinae and two labelled as "Helix christinae var." in the NHM. The latter two samples differ from the former one exactly in the traits mentioned by Adams. Thus, although they are not labelled as var. carinifera, it is clear that they represent syntypes of that taxon.
The syntypes of Helix christinae var. carinifera are identical with the types of Helix subsimilis, and thus, the latter is a junior synonym of the former. Although both Möllendorff (1884) and Gredler (1884) synonymised H. subsimilis with H. carinifera, this species (L. carinifera) has been mentioned in the literature as Laeocathaica subsimilis. Laeocathaica stenochone is also identical with both Helix christinae var. carinifera and Helix subsimilis, and therefore, it is also treated as a junior synonym.  Distribution. The type localities and the newly collected sample suggest that this species lives more upstream in the Yangtze valley than L. filippina. The samples from Moupin (Baoxing County, Sichuan) are probably erroneous. We indicated only the newly collected sample on the map (Fig. 14).
Remarks. We found three samples in the NHM. One of them, containing two shells, was labelled Helix christinae. The other two lots, labelled "Helix christinae var.", contained three shells each. The latter two samples are probably syntypes of Helix christinae var. carinifera, described in the same publication (Adams 1870; see further details under that species). None of the two Helix christinae shells (NHMUK 1870.7.16.6) are identical with the shells figured in the original description (Adams 1870: pl. 27, figs 4, 4a). However, the indication of the collector (Swinhoe) agrees with the collector mentioned in the original description. Thus, we treat the two shells of that lot as syntypes.
Diagnosis. A small Laeocathaica species with many (8.5) whorls, conical dorsal side, rounded body whorl and single, small basal tooth that is situated close to the columella.
Description. Shell sinistral, depressed, dorsal side conical with protruding apex, body whorl shouldered; colour chalk white with a single brownish belt below shoulder; entire shell consists of 8.5 whorls, protoconch consists of 1.75-2 whorls, very finely granulose, conspicuously elevated compared to first teleoconch whorls; teleoconch with fine, irregular growth lines, without any notable sculpture, although both examined shells were corroded; last quarter whorl with slight subsutural furrow; aperture semilunar, very strongly oblique to shell axis; peristome sharp, very slightly expanded dorsally, with thickening situated behind peristome edge; basal tooth blunt, elongated, situated ca. at the middle of basal peristome; parietal callus inconspicuous, appears only as thick calcareous layer; umbilicus open, narrow, shows all whorl, with the last half of body whorl extremely widened, resulting in a "9"-shape.
Measurements (in mm): D: 11.5-11.6; H: 5.2-5.3 (n = 2). Differential diagnosis. The most similar species is L. polytyla, which is usually larger, has one whorl more, has a more elevated spire with a domed dorsal side, a rounded body whorl, and a comparatively smaller basal tooth situated closer to the columella.
Etymology. This new species is named after S. Hisano, who collected the type material.

Laeocathaica minwui
Description. Shell sinistral, depressed, with domed dorsal side, keel strong, situated in the middle of body whorl, whitish; dorsal side latte-coloured, with darker and paler areas alternating as the shell grows; ventral side with white and pale brownish (latte) spiral bands forming a marmorated colour pattern; inner side of umbilicus with brownish spiral band; protoconch light brownish, ca. 1.5 whorls, finely granulose, slightly protrudes above first whorls of teleoconch; entire shell consists of six whorls; dorsal side finely ribbed, ventral side smoother, only with growth lines; umbilicus ca. one third of shell width; shows all whorls; periumbilical keel absent; aperture oblique to shell axis, oval, without incision at the position of keel; peristome white, expanded and slightly thickened, but not reflexed (only in direction of umbilicus); parietal callus practically absent, only with some additional translucent calcareous layer.
Measurements (in mm): D = 23.1, H = 9.1 (holotype). Differential diagnosis. Laeocathaica minwui sp. nov. has been confused with L. christinae in museum collections, probably due to the lack of examination of the types of L. christinae. However, L. christinae has a flatter dorsal side, a more uppersituated peripheral keel, a darker brown (instead of latte) colour, a more uniformly white ventral side with a brown spiral band inside the umbilicus, and brownish spots. In contrast, in the new species the ventral side is characterised by a marmorated (marbled-like) pattern resulted by the fusing of whitish and pale brown spiral bands. Laeocathaica filippina has a notched aperture at the position of the peripheral keel, a more brownish colour, and a less marmorated ventral side. See also Table 3.
Etymology. This new species is dedicated to and named after Dr. Min Wu, the leading expert of Chinese Camaenidae.
Distribution. This new species is only known from historical samples from the Yangtze valley. Other samples labelled as being collected from Sichuan are not precise enough to understand their geographic origin.    Description. Shell sinistral, depressed, strongly keeled, dorsal side domed, ventral side conical; shell colour basically brownish, greyish, latte-coloured, with whitish stripes; as a result dorsal surface mosaic-like, ventral side striped; keel always white, there is always a brownish belt just below the keel, periumbilical keel always white; entire shell consists of 9-9.5 whorls; protoconch consists of 1.5 whorls, brownish, seemingly smooth, extremely finely granulose, rather matte; white keels of every whorl slightly elevated from dorsal surface, but dorsal surface almost continuous, suture practically absent; dorsal side with fine, irregular wrinkles (most wrinkles stand alone, but some of them unite to each other); ventral surface with less prominent wrinkles; umbilicus rather narrow, regular funnel-shaped, shows all whorls; periumbilical keel blunt; aperture semilunar, peristome very slightly expanded, but not reflexed or thickened; palatal swelling whitish, with two prominent denticles, situated in some distance from peristome; parietal wall with some whitish thickening in adult shells. Juveniles reverse conical in shape; several apertural barriers are built during lifetime; palatal swelling of juveniles appears as a continuous ridge, although the two denticles recognisable.
Remarks. The single juvenile shell of sample 2016/64 has a narrower, blunter umbilical keel than the holotype, and it is possible that it belongs to another species. However, the juvenile shell of sample 2016/68 is identical with the holotype.    Distribution. Known from two sites in Southern Gansu Province (Fig. 24). Remarks. Laeocathaica prionotropis subsp. albocincta agrees in size and shell shape with the nominotypical form, and therefore it is here synonymised with Laeocathaica prionotropis.

Discussion
Although we list and publish photographs of all Laeocathaica species in this work, the taxonomy of this group is still far from being solved. Following previous authors, we classify only sinistral species in Laeocathaica. However, it is very probable that the coiling direction has changed multiple times during the evolution of Bradybaeninae inhabiting the arid regions of central China. Furthermore, sinistral species such as Bradybaena micromphala (Möllendorff, 1899) and B. eris (Möllendorff, 1899) also inhabit southern Gansu, and are similar to Laeocathaica species in most traits except for the narrow umbilicus. Future investigations will probably reveal that the latter two species (and maybe some other similar ones from the region) are relatives of Laeocathaica rather than Bradybaena.
One of the main outcomes of the present paper is the clarification of some names that have been incorrectly used in the literature and in museum collections because the types were not examined. One such case is Helix christinae var. carinifera H. Adams, 1870, which resulted in being a senior synonym of Laeocathaica subsimilis (Deshayes, 1874) after examination of both type species. The other case is that of L. minwui sp. nov., which was called L. christinae (H. Adams, 1870) in museum collections, because the types of the "real" L. christinae had not been examined.
The other important outcome of the present study is the recognition of continuous dorsal surface variability from flat to domed, the strongly keeled to rounded body whorl, the colouration, and shell size (D: 19-32 mm) across the taxa Laeocathaica amdoana, L. distinguenda, L. tropidorhaphe, and L. dangchangensis. Table 4 summarises the co-occurrence patterns between Laeocathaica species, showing which species pairs are reproductively isolated, true biological species, and Fig. 27 shows all Laeocathaica species.