Plectopylidae Möllendorff, 1898

Páll-Gergely, Barna, 2018, Systematic revision of the Plectopylinae (Gastropoda, Pulmonata, Plectopylidae), European Journal of Taxonomy 455, pp. 1-114 : 7-8

Family Plectopylidae Möllendorff, 1898

Plectopylidae Möllendorff, 1898: 147 .

Type genus

Plectopylis Benson, 1860 .

Diagnosis

Shell sinistral or dextral, small to very large ( 5–35 mm); flat, depressed-conical or conical; dorsal surface concave, flat (even in those cases the protoconch usually protrudes above surface), conical or domed; protoconch sculpture variable between genera (ribbed, wrinkled, reticulated, tuberculated); dorsal surface usually with reticulated structure (consisting of spiral and radial lines); ventral surface usually with less prominent sculpture; deciduous periostracal folds might be present on the periphery of body whorl; aperture oblique to shell axis; peristome expanded, sometimes reflected; parietal callus present, V- or slightly S-shaped, apertural fold present or absent; multiple armatures formed during growth, the last one 0.25–0.75 whorls behind aperture; parietal wall with one or two vertical lamellae, usually with additional horizontal plicae above and below the lamellae or anterior to them; palatal wall with 6–7 plicae, which are variable in morphology: straight and horizontal, depressed Z-shaped, sometimes divided in the middle (most often when there is a single parietal lamella), or the fourth and fifth fuse to each other, forming a vertical plate (most often where there are two parietal lamellae).

Ommatophoral retractor (in sinistral specimens the left, in dextral specimens the right retractor) runs between the penis and vagina; atrium short; penis very short, vestigial to well-developed, without verge, usually with parallel folds internally; calcareous crystals may be present between folds; epiphallus usually present, bound to penis by weak fibres; penial caecum short or absent, retractor muscle inserts on penial caecum or, if caecum is absent, at the penis-epiphallus transition; vas deferens long, usually thickened before entering spermoviduct; vagina well-developed, usually U-shaped, sometimes with thickened ‘vaginal bulb’ formed at turning point of ‘U’, attached to body wall with multiple, short muscle fibres; vagina internally with longitudinal folds; spermoviduct long; bursa copulatrix with slender stalk of variable length and usually an ovoid bursa; diverticulum usually present, short ovoid to very long, slender, usually originates near originating point of bursa copulatrix; all species ovoviviparous, embryo sac with several small calcareous crystals on its surface; talon normally developed, elongated, albumen gland of variable length.

Radula elongated, but not very slender; teeth arranged in rows; laterals in straight rows perpendicular to central column; marginals in anteriorly pointed, slightly oblique rows, central tooth with a single, small to medium-sized cusp (sometimes absent), which is smaller or larger than ectocones of first laterals, but always smaller than endocones of first laterals; first laterals with a large endocone and a small ectocone; transition between laterals and marginals is gradual with endocone being gradually divided into two cusps, ectocones usually remain undivided.

Distribution

The family Plectopylidae extends from the southern Himalayan region ( Nepal and northeastern India) throughout Myanmar, the Malay Peninsula, southern and northern Thailand, northern Laos, northern Vietnam, central, southern and eastern China ( Yunnan, Sichuan, Guizhou, Chongqing, Hubei, Hunan, Guangxi, Guangdong, Jiangxi, Zhejiang and Fujian Provinces) to Taiwan and southern Japan (Miyako Island) ( Fig. 3 ).

Figures

Fig. 3. Distribution of the extant Sinicolinae subfam. nov. (ruled area) and Plectopylinae Möllendorff, 1898 (grey shaded area). Mainly after Páll-Gergely & Hunyadi (2013) and Páll-Gergely et al. (2015b, 2015c, 2016).