Two new camaenid land snails (Eupulmonata) from Central China

Abstract Two new camaenid land snails are reported from Central China. The new genus, represented by Sinochloritislii Wu & Chen, gen. & sp. nov., the type of the genus from Sichuan, is close to Yakuchloritis Habe, Nipponochloritis Habe, Neochloritis Minato and Trichochloritis Pilsbry, but is well characterized by the smooth adult shell, highly developed epiphallic papilla, absence of penial caecum, and the presence of an epiphallus-binding muscle that binds the proximal epiphallus to the distal penis. A new species Bradybaenalinjun Wu & Chen, sp. nov. is described from Hubei Province and is characterized by having two shell bands, a spoon-shaped love dart and the proportionally shortest mucous glands among Chinese congeners.


Introduction
Trichochloritis Pilsbry, 1891 (type species Helix breviseta Pfeiffer, 1862, original designation) was established as a subgenus of Chloritis Beck, 1837 to accommodate species that featured a "shell depressed, rather thin, the spire low-convex or plane, last whorl not carinated, but usually obtusely angled around the umbilicus; but little deflexed in front; epidermis not deciduous; apex, as well as the whole shell, hirsute or marked by hair-scars arranged in regular lines. Lip narrowly expanded or reflexed" (Pilsbry 1891). Trichochloritis is now recognized as a distinct genus (Schileyko 2007(Schileyko , 2011, which ranges from South China to the Philippines and in Japan (Pilsbry 1891, Azuma 1995, Schileyko 2011. Based on conchological and anatomical features (Azuma 1995), species of the Japanese region that were previously included in Trichochloritis have been treated as three separate genera, namely Yakuchloritis Habe, 1955, Neochloritis Minato, 1982and Nipponochloritis Habe, 1955, and were assigned to the family Bradybaenidae (=Bradybaeninae sensu Bouchet et al. 2017) by Schileyko (2004). Based on the genital morphology of Trichochloritis brevidens (Sowerby, 1841) (Schileyko 2007; Table 1), Trichochloritis is unambiguously distinct from the Japanese genera.
Until now we have little idea if the species previously placed in Trichochloritis form a monophyletic group, although some recent work suggests that Trichochloritis as currently understood, consists of species from the Bradybaenidae (=Bradybaeninae sensu Bouchet et al. 2017) and from the Camaenidae (=Camaeninae sensu Bouchet et al. 2017) (Schileyko 2003(Schileyko , 2004(Schileyko , 2007. Here, we report a new species  (Habe 1955, Minato 1982, Azuma 1995, Schileyko 2004, Schileyko 2007. EBM -epihallus-binding muscle, the muscle binding proximal epiphallus to distal end of penis; Ep -epiphallus; EpP -epiphallic papilla; Fl -flagellum; PC -penial caecum; PS -penis sheath.  from Sichuan that is conchologically most similar to T. percussa but shows marked differences from Trichochloritis, Yakuchloritis, Neochloritis and Nipponochloritis. In addition, we describe a new Bradybaena species discovered during our recent field work in Hubei Province.

Methods
Living specimens were relaxed by drowning in water before being transferred to 70% ethanol for fixation, which was replaced with ethanol of the same concentration after three days. The shell and genitalia were measured with digital vernier calipers and from photographs to the nearest 0.1 mm. Whorl number was recorded as described by Kerney and Cameron (1979), with 0.125 whorl accuracy. Soft parts were measured after the specimens were sufficiently fixed in 70% ethanol. Directions used in descriptions: proximal, toward the genital atrium; distal, away from the genital atrium. Abbreviations: At -atrium; BC -bursa copulatrix; BCD -bursa copulatrix duct; DS -dart sac; DVM -membranous sac surrounding terminal genitalia; EBM -epiphallus-binding muscle, the muscle binding proximal epiphallus to distal end of penis; Ep -epiphallus; EpP -epiphallic papilla; Fl -flagellum; fma -fully mature animal; fms -empty fully mature shell; FO -free oviduct; HBUMM -mollusc collection of the Museum of Hebei University, Baoding, China; MG -mucous glands; P -penis; PC -penial caecum; PR -penial retractor muscle; PP -penial pilaster; PS -penis sheath; Va -vagina; VD -vas deferens. Description. Shell depressed. Whorls convex. Suture rather impressed. Protoconch and teleoconch densely and evenly covered with fine granules. Adult shell not hairy or scaly. Peristome abruptly angulated at top; narrowly and uniformly reflexed. Shell glossy; uniformly colored; not banded.

Systematics
Genitalia. Penis sheath absent. Penis externally simple; internally with several pilasters. Epiphallus internally with a large epiphallic papilla that enters penis; externally with proximal part connected with distal end of penis by strong muscles (epiphallusbinding muscles). Flagellum present. Vas deferens uniformly thin.
Etymology. This new genus is named after "sino" (=China) and "chloritis" (the genus used to include many Chinese Trichochloritis species).
General anatomy (Fig. 3). A heart-shaped head gland between ommatophore insertions present on inner body wall (Fig. 3C, arrowed), externally with a visible gland pore (Fig. 3A, arrowed). On internal body wall, at the base of ommatophore with two groups of glands each consisted of numerous small sacs (Fig. 3C). On left side of mantle edge, a leaf-shaped appendage present (Fig. 3D, E). Body blueish purple with scattered lighter spots (Fig. 3H). Sole dirty white. Jaw arcuate; with twelve more or less projecting ribs (Fig. 3F).
Etymology. This species is named in honor of Dr. Chenliang Li who collected and sent us the holotype (HBUMM08294).
Etymology. The new species is named after the legendary tribal leader "Lin-Jun (廪君)" of the Tujiazu people who live at the type locality.
Distribution. Hubei (Changyang), only known from the type locality. Ecology. This species was found living in a well-established secondary forest, on limestone cliffs, often in cracks (Fig. 10). A large number of broken shells, presumably caused by bird predation, were observed at the type locality.
Taxonomic remarks. The new species is assigned to Bradybaena because of the presence of a smooth protoconch, membranous sac surrounding terminal genitalia, poly-layered structure in dart apparatus, two mucous glands and the absence of a flagellum; characters that are consistent with the type of the genus B. similaris (Wu 2004).
Only a few Chinese species in the subfamily Bradybaeninae have double bands. The double-banded shells occur more frequently in Cathaica Möllendorff, 1884 than in Bradybaena where only four species exhibit double bands, namely B. billiana (Heude, 1882), B. mimicula (Heude, 1888), B. diplodesma (Möllendorff, 1899), B. sueshanensis Pilsbry, 1934(Heude 1882, 1888Möllendorff 1899;Pilsbry 1934). Although the new species has double bands, in aspect of shell morphology it most resembles B. qixiaensis Wu & Asami, 2017. However, the new species has very short mucous glands which are proportionally the shortest in the subfamily Bradybaeninae, the thyrsiform mucous gland duct, and the spoon-shaped love dart, which distinguish this species from all Chinese Bradybaena species with known genital anatomy.