Dicharax pongrati Jirapatrasilp & Tongkerd, 2021

Jirapatrasilp, Parin, Pall-Gergely, Barna, Sutcharit, Chirasak & Tongkerd, Piyoros, 2021, The operculate micro land snail genus Dicharax Kobelt & Moellendorff, 1900 (Caenogastropoda, Alycaeidae) in Thailand, with description of new species, Zoosystematics and Evolution 97 (1), pp. 1-20 : 1

publication ID

https://dx.doi.org/10.3897/zse.97.59143

publication LSID

lsid:zoobank.org:pub:1D5553BA-2489-4F2C-9527-B7E46B9B432B

persistent identifier

https://treatment.plazi.org/id/92117A2E-1578-41D6-845C-8223B815B272

taxon LSID

lsid:zoobank.org:act:92117A2E-1578-41D6-845C-8223B815B272

treatment provided by

Zoosystematics and Evolution by Pensoft

scientific name

Dicharax pongrati Jirapatrasilp & Tongkerd
status

sp. nov.

Dicharax pongrati Jirapatrasilp & Tongkerd sp. nov. Figs 6D View Figure 6 , 7C View Figure 7 , 12D View Figure 12

Type material.

Holotype CUMZ 7430/1 (Fig. 12D View Figure 12 ), paratypes CUMZ 7430/2 (56 shells; Figs 6D View Figure 6 , 7C View Figure 7 ), HNHM (2 shells), NHMUK 20200328 (2 shells) and SMF (2 shells) from Doi Chiang Dao, Chiang Mai Province, Thailand, 19°14'26.7"N, 98°52'49.8"E, 24-28 May 1997, coll. S. Panha, J.B. Burch, P. Dumrongrojwattana.

Diagnosis.

Shell medium-sized (SH up to 2.3 mm, SW up to 4.4 mm), lenticular, depressed-conical. Spire ca. ¼ of shell height. R1 with regular, thread-like ribs; R2 three times longer than R3; R2 with ca. 76 ribs. R3 strongly reduced, without swelling. Aperture round. Inner peristome with two shallow indentations. Outer peristome expanded, slightly reflected. Umbilicus elliptical. Operculum multispiral, with or without elevated lamella.

Description.

Shell medium-sized (SH up to 2.3 mm, SW up to 4.4 mm), lenticular, depressed-conical, solid, translucent, yellowish to pale orange. Shell outline oval in apical view, spire ca. ¼ of shell height. Whorls ca. 4 and 1/8. Protoconch low, ca. two whorls, glossy and smooth. R1 ca. 1¾ whorls with fine, regular, thread-like ribs; with ca. 17 ribs in ¼ whorl adjoining R2, ribs more elevated and sharper near suture and flatter near umbilicus and at the edge of body whorl. Boundary between R1 and R2 distinct as R2 contains denser and thicker ribs than R1; R2 with ca. 76 ribs that are curved towards aperture; R2 ca. 1/3 whorl, three times longer than R3. Boundary between R2 and R3 distinct due to shallow constriction; R3 strongly reduced, without swelling, practically the constriction continues directly to outer peristome. Aperture round; slightly oblique to shell axis. Peristome double with regular outer peristome. Inner peristome slim, slightly protruding, with two shallow indentations. Outer peristome thickened, expanded, slightly reflected, multilayered (visible in lateral view). Umbilicus elliptical, open, approximately one third of shell width. Operculum either thin with low lamella or thick with elevated lamella.

Etymology.

In honor of Pongrat Dumrongrojwattana, a Thai malacologist who has studied micro land snails of Thailand and was one of the collectors of this new species.

Distribution.

The new species is known only from the type locality in Chiang Mai Province, Thailand.

Remarks.

Differs from the sympatric and similar depressed-conical D. pratatensis in having a wider and more depressed shell, a much longer R2, a shorter R3 without a swelling and two shallow indentations at the inner peristome.

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

SubClass

Caenogastropoda

Order

Architaenioglossa

Family

Cyclophoridae

Genus

Dicharax