Chersaecia perarcta perarcta ( Blanford, 1865 )

Páll-Gergely, Barna, 2018, Systematic revision of the Plectopylinae (Gastropoda, Pulmonata, Plectopylidae), European Journal of Taxonomy 455, pp. 1-114 : 50-51

publication ID

https://doi.org/ 10.5852/ejt.2018.455

publication LSID

lsid:zoobank.org:pub:C445E95B-446A-4601-AAA3-C1CCBAB627F9

DOI

https://doi.org/10.5281/zenodo.3818788

persistent identifier

https://treatment.plazi.org/id/03CC87A0-6C1D-8A15-FDFB-FB5246F3F8A0

treatment provided by

Valdenar

scientific name

Chersaecia perarcta perarcta ( Blanford, 1865 )
status

 

Chersaecia perarcta perarcta ( Blanford, 1865) View in CoL

Figs 21N–S, 22C–D

Helix (Plectopylis) perarcta Blanford, 1865: 75 , 94 [“Mya Leit Doung, near Ava”].

Helix perarcta – Pfeiffer 1868: 397–398; 1869: 502, pl. 108, figs 13–15.

Helix (Plectopylis) perarcta – Hanley & Theobald 1870: 7, pl. 13, fig. 3. — Godwin-Austen 1875b: 613, pl. 74, fig. 4. — Nevill 1878: 71. — Tryon 1887: 162, pl. 35, figs 91–95. — Godwin-Austen 1888: 243 [“Hlindet, 1200 feet ”].

Plectopylis perarcta View in CoL – Gude 1896a: 155, fig. 19a–c; 1908: 88.

Plectopylis (Chersaecia) perarcta View in CoL – Gude 1899d: 148; 1899e: 175; 1914b: 106–108, fig. 50a–c.

Chersaecia perarcta View in CoL – Páll-Gergely et al. 2015c: 10.

Diagnosis

Main plica present.

Material examined

Types

MYANMAR: 6 shells (probably syntypes), Burma, Myaleit doung, Ava, ( NHMUK 1906.2.2.275); 3 shells (probably syntypes), Myaleit doung, near Ava ( NHMUK 1888.12.4.1521–1523).

Additional material

MYANMAR: 3 shells, Burma, coll. Godwin-Austen ex Blanford ( NHMUK 1909.3.15.61); 1 shell, Burma, Ava, coll. A. S. Kennard ( NHMUK); 3 shells, Burma, Ava ( NHMUK).

THAILAND: 1 shell, Chiang Rae Province, limestone knoll, 4 km NE of Ban Pa Ngae, 19°34′19″ N, 99°59′14″ E, 410 a.s.l. m, 12 May 1988, F.G. Thompson leg. ( UF 380334); 20 shells, 3 juv. shells, same data as for preceding ( UF 448575); 2 shells, same data as for preceding ( HNHM 97459); 8 shells, 6 juv. shells, same data as for preceding but 13 May 1988 ( UF 380344); 1 shell, Wat Phra That Tham Doi Kong Kao, ca 5.5 km W of Chiang Rai, in clay in Temple Cave, 19°54′46.34″ N, 99°46′33.64″ E, Sep. 2007, A. Reischütz leg. ( HNHM 97458); 2 shells, 2 damaged shells, same data as for preceding (coll. PGB); 2 shells, same data as for preceding ( NHMW 108116); 24 shells, 10 damaged shells, same data as for preceding (coll. REI).

Description of the type series

SHELL. Sinistral, tightly coiled, flat, only protoconch protrudes above dorsal surface; colour greyish yellow to light brown; protoconch large, consists of 2.5–2.75 whorls, with large tubercles, no radial lines visible; teleoconch with very fine ribs, covered by fine periostracal folds; spiral lines absent; periostracum more prominent inside sutures; whorls 5.75–6, separated by very deep suture; umbilicus regularly shaped infundibular, only last whorl widening abruptly; body whorl rounded; peristome reflected and slightly thickened; parietal callus elevated, sharp, V-shaped.

Two shells were opened. Parietal wall with a single, strongly developed lamella, which has the lower end elongated slightly posteriorly; upper end very slightly elongated in both anterior and posterior directions; main plica long, free from lamella, reaches parietal callus; one of the shells had the main plica and the apertural fold separated (probably subadult shell); inner end of main plica situated lower (closer to the lower suture); lower plica slender, runs along and parallel with lower suture and also reaches parietal callus; there is a very short additional plica between the main and lower plica; all plica start in one vertical line anterior to lamella. Palatal plicae six; first and sixth straight, run parallel with sutures; middle plicae more or less horizontal, straight or slightly wavy; sometimes with additional posterior denticle.

MEASUREMENTS (in mm). D = 10.9–12.8, H = 4–4.5 (UF 38344, n = 5); D = 11.2–13, H = 3.7–4.5 (loc. “ 5.5 km west of Chiang Rai ”, coll. REI); D = 10.6–11.7, H = 3.6–4.1 (type series, NHMUK 275.06.2.2, n = 3).

Differential diagnosis

See under Chersaecia perarcta simplex .

Distribution

Chersaecia perarcta perarcta has been reported from the vicinity of Ava, Mandalay Region, Myanmar, and from northern Thailand (see also Fig. 17 View Fig ).

Remarks

Typical shells have a well-developed apertural fold, which is in contact with the parietal callus. The apertural fold of the shells collected 4 km NE of Ban Pa Ngae is free from the parietal callus. Most of the shells (23 out of 27) from 5.5 km W of Chiang Rai lacked the apertural fold, and all four opened shells lacked a lower plica.

NHMUK

Natural History Museum, London

UF

Florida Museum of Natural History- Zoology, Paleontology and Paleobotany

HNHM

Hungarian Natural History Museum (Termeszettudomanyi Muzeum)

NHMW

Naturhistorisches Museum, Wien

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Order

Stylommatophora

SuperFamily

Plectopyloidea

Family

Plectopylidae

SubFamily

Plectopylinae

Genus

Chersaecia

Loc

Chersaecia perarcta perarcta ( Blanford, 1865 )

Páll-Gergely, Barna 2018
2018
Loc

Chersaecia perarcta

Pall-Gergely B. & Budha P. B. & Naggs F. & Backeljau T. & Asami T. 2015: 10
2015
Loc

Plectopylis (Chersaecia) perarcta

Gude G. K. 1914: 106
Gude G. K. 1899: 148
Gude G. K. 1899: 175
1899
Loc

Plectopylis perarcta

Gude G. K. 1896: 155
1896
Loc

Helix (Plectopylis) perarcta

Godwin-Austen H. H. 1888: 243
Tryon G. W. 1887: 162
Nevill G. 1878: 71
Godwin-Austen H. H. 1875: 613
Hanley S. C. T. & Theobald W. 1870: 7
1870
Loc

Helix perarcta

Pfeiffer L. 1869: 502
Pfeiffer L. 1868: 397
1868
Loc

Helix (Plectopylis) perarcta

Blanford W. T. 1865: 75
1865
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