Systematic revision of the Plectopylinae (Gastropoda, Pulmonata, Plectopylidae) Author Páll-Gergely, Barna 31E196E9-5A51-4295-9A36-D5DA689502B7 Centre for Agricultural Research, Hungarian Academy of Sciences (MTA), Herman Ottó Street 15, Budapest, H- 1022, Hungary. pall-gergely.barna@agrar.mta.hu text European Journal of Taxonomy 2018 2018-08-16 455 1 114 journal article 22297 10.5852/ejt.2018.455 44a2fcf6-cc1b-4c07-9554-dd6dd279a76d 3817707 C445E95B-446A-4601-AAA3-C1CCBAB627F9 Plectopylis anguina ( Gould, 1847 ) Figs 34A , 35A Helix anguina Gould, 1847: 218–219 [“Manko, near Newville, Province of Tavoy”]. Helix ( Plectopylis ) anguina – Hanley & Theobald 1870: 7 , pl. 13, fig. 7. — Godwin-Austen 1875b: 613 . — Nevill 1878: 72 . — Tryon 1887: 165 , pl. 35, fig. 6. Plectopylis anguina – Gude 1898d: 76 , fig. 79a–f (on page 75). Plectopylis ( Plectopylis ) anguina – Gude 1899d: 148 ; 1899e: 175 ; 1914b: 136–138 , fig. 69a–f. — Johnson 1964: 40 , pl. 41, fig. 5. (fig. caption before pl. 38, shell photo mixed up with Cyclostoma ( Cyclophorus ) cucullata ). Diagnosis A very large, sinistral species with conspicuously flattened shell, and bluntly keeled body whorl. Material examined Types MYANMAR : 2 shells, paralectotypes , Tavoy ( NHMUK 20140812); 1 shell, paralectotype , Manko, Tavoy, coll. Gould ( MCZ 147595); 1 shell, lectotype , Burmah, Manko, near Newville, Tavoy, Mrs Vinton leg., coll. Gould ( MCZ 169042); 1 shell, paralectotype , same data as for preceding ( MCZ 169043). I examined the paralectotypes in the NHM, and received photographs of specimens deposited in the MCZ. Additional material MYANMAR : 1 shell, Burmah, Moulmein, 1908, coll. C.R. Boettger ( SMF 102815 ); 1 shell (mixed sample with Plectopylis bensoni ) ( SMF 172059); 1 shell, Burma, coll. Bosch ex Rolle ( SMF 345109); 3 shells, Mergui ( NHMUK ); 1 shell, Rangoon , Moulmein, coll.Godwin-Austen ( NHMUK 1903.7.1.739); 1 shell, Rangoon , Moulmein, coll. Blanford ( NHMUK 1906.1.1.732); 1 shell, Molmein ( NHMUK ); 2 shells, Damathat Hill ( NHMUK 1888.12.4.1553–1554). Description of the type series SHELL. Sinistral, strongly depressed, dorsal surface slightly concave, but protoconch protrudes to reach level of dorsal surface; whorls 5–5.75 (n = 2); body whorl bluntly keeled; whole shell brownish with yellowish stripes, dorsal side seems to be darker than ventral; one specimen was almost completely brown above and striped below, whereas other shells were striped above and almost completely pale on their ventral side; protoconch matt, almost smooth, with irregular, inconspicuous growth lines and extremely small granular structure; teleoconch dominated by irregular growth lines, and some reticulated parts on dorsal surface (between end of protoconch and beginning of last whorl); periphery of body whorl almost smooth; aperture almost completely facing downwards; peristome strongly thickened and slightly reflected; parietal callus quite low, slightly depressed V-shaped; apertural fold starts at some distance from parietal callus. One opened shell was examined. Lambda-complex complete; both legs with slight elongations anteriorly and posteriorly; upper branch slightly longer than elongation of left leg; main plica connected to the right leg. Palatal plicae typical of Plectopylis . MEASUREMENTS (in mm). D = 26.2–30.4, H = 7.1–7.9 ( paralectotypes , NHMUK 20140812, n = 2). Table 3. Key characters, most similar species and distribution of species of Plectopylis .

Species	Key traits	Most similar species	Distribution
P. anguina	flat shell, strongly oblique aperture, bluntly keeled body whorl	P. bensoni	southern Myanmar
P. bensoni	robust shell, rounded body whorl	P. anguina , P. cairnsi	southern Myanmar
P. cairnsi	main plica free from lambda- complex	P. bensoni , P. thompsoni sp. nov.	southern Thailand (Krabi Province
P. crassilabris sp. nov.	robust shell, thickened peristome, main plica absent	P. linterae	southern Thailand (Chon Buri, Chachoengsao, Chantaburi, Rayong provinces)
P. cyclaspis	keeled body whorl	–	southern Myanmar (around Mawlamyine)
P. karenorum	flat, thin-walled shell, tiger stripes	–	Myanmar (Bago)
P. linterae	small, robust shell, main plica present	P. crassilabris sp. nov.	Myanmar (Bago)
P. malayana sp. nov.	brown shell with periostracal folds, short plica attaches to right leg of lambda-complex	P. cairnsi	border region of Thailand and Malaysia
P. thompsoni sp. nov.	large, flat shell, right leg of lambda-complex absent	P. cairnsi	southern Thailand (Krabi and Trang provinces)

Differential diagnosis Plectopylis anguina differs from P. bensoni by the lighter, flatter shell, the bluntly keeled body whorl, the more elongated aperture and the overall more elongated (ovate) shell outline. Distribution The species has been reported from a few southern Burmese localities. Remarks Gude (1914b) mentioned that Plectopylis anguina differs from P. repercussa in features of the parietal plication. Namely, “the lower arm of the bifurcation” is longer than the upper, whereas the reverse is true in P. repercussa . In the opened paralectotype in the NHM this was not the case, because the upper arm was very slightly longer then the lower leg. The other difference mentioned by Gude is that the lower plica does not extend beyond the left leg in P. anguina , but does so in P. repercussa . My observations do not match those of Gude, because the lower plica does not exceed the left leg in the opened paralectotype of P. repercussa . Therefore, this character does not distinguish the two species. Based on this evidence, P. anguina is a valid species, different from P. bensoni (of which P. repercussa is a synonym) because of its characteristic flat shell, strongly oblique aperture and bluntly keeled body whorl.