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 Chersaecia nagaensis nagaensis (Godwin-Austen, 1875) Figs 21G–I, 22A Helix ( Plectopylis ) nágáensis Godwin-Austen, 1875b: 609–610 , 612, pl. 73, fig. 4 [“Prowi, head of the Lauier river, Nágá hills, 5000 feet ”] (partim). Helix ( Plectopylis ) nagaensis – Nevill 1878: 72 . — Tryon 1887: 161 , pl. 35, figs 78–79. Plectopylis nagaensis – Gude 1897a: 206–207 , fig. 33a–d. Plectopylis ( Chersaecia ) nagaensis – Gude 1899d: 148 ; 1899e: 175 ; 1914b: 96–97 , fig. 42a–d. Chersaecia nagaensis – Páll-Gergely et al. 2015c: 10 . Diagnosis Main plica present. Material examined Types INDIA : 10 shells, syntypes of P. nagaensis , Naga Hills, Prowi, head of Lanier Valley, coll. Godwin- Austen ( NHMUK 1903.7.1.753). Additional material INDIA : 1 shell, Japvo Pk, Naga Hills ( NHMUK 1903.7.1.3493); 2 adult shells (+ 2 juv. of questionable identity), Manipur Hills, Ogle leg. ( NHMUK 1903.07.01.777); 1 shell, Naga Hills, Ogle leg., coll. Godwin-Austen ( NHMUK ); 9 shells, Prowi, NE Manipur , coll. Godwin-Austen ( NHMUK ); 1 shell, Naga Hills, Hungerford leg. ( NHMUK 1891.3.17.352); 2 shells, coll. Godwin-Austen ( NHMUK 1909.3.26.74); 2 shells, Naga Hills ( NHMUK ). Description SHELL. Sinistral, usually with dense brownish periostracum; two shells lacking periostracum had yellowish grey colour and densely alternating reddish and yellowish stripes on the dorsal surface; below periostracum shell surface very finely reticulated as a result of fine, dense radial ribs and nearly equally strong spiral striation; spire elevated, dorsal side domed/depressed conical; protoconch consists of 2.5–2.75 whorls, very finely granular, only last ca one whorl with rough irregular, radial sculpture; whorls 6.25–6.5; teleoconch whorls separated by a shallow suture; aperture rounded; peristome whitish, expanded and reflected; parietal callus slightly S-shaped, approximately as strongly developed as peristome; apertural fold strong, connected to parietal callus; umbilicus relatively narrow and deep, funnel-shaped. Four opened shells were examined. Parietal side with a single lamella; both ends of lamella slightly elongated posteriorly; lamella with a very slight elongation anteriorly in position of intermediate plica; an opened shell (“ India ”, NHMUK 1874.9.26.3) with a short intermediate plica free from lamella; main plica free from lamella, reaching apertural fold; lower plica short, situated under the lamella, slightly extends beyond lamella in both anterior and posterior directions. Palatal wall with six plicae; first curved and situated near suture; second considerably elongated anteriorly, with an additional, small denticle at its posterior end; above this denticle there is another tiny denticle; third and fourth plicae shorter than second, slightly depressed Z-shaped; fifth plica shorter than fourth, divided in the middle (only visible from inside); sixth plica short, situated near suture, and positioned under the line of posterior denticles/ posterior parts of divided plicae. MEASUREMENTS (in mm). D = 11.6–12.2, H = 6.3–6.8 (n = 3, type series of nagaensis ). Differential diagnosis The main plica is long, and connected to the apertural fold (absent in Chersaecia nagaensis muspratti ). Fig. 22 (next page). A–F . Shells of species of Chersaecia Gude, 1899 . A . C. nagaensis (Godwin-Austen, 1875) , syntype (NHMUK 1903.7.1.753). B . C. nagaensis muspratti (Gude, 1897) , syntype (NHMUK 1912.4.16.320). C . C. perarcta perarcta ( Blanford, 1865 ) , probable syntype (NHMUK 1903.7.1.753). D . C. perarcta perarcta (NHM 97458). E–F . Shell and protoconch of C. perarcta simplex ( Solem, 1966 ) , paratype (ZMUC-GAS-487). G–H . Genitalia of C. perarcta simplex ( Solem, 1966 ) (ZMUC- GAS-487). G . Male part of the genitalia. H . Opened penis (arrow shows thickened part of penial folds). Scale bars: A–E (upper scale) = 10 mm ; F–H = 1 mm . Photos: H. Taylor (A–C), T. Deli (D) and B. Páll- Gergely (E–F). Distribution All known localities are within the Naga Hills and Manipur , northeastern India . Remarks The ‘dwarfed variety’ of Plectopylis nagaensis , which was mentioned in the original description of the species, is described here under the name Chersaecia shiroiensis subnagaensis subsp. nov.