Dicharax pratatensis (Panha & Burch, 1997)

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

Dicharax pratatensis (Panha & Burch, 1997) Figs 6B , 8C, D

Alycaeus pratatensis Panha & Burch, 1997: 119-122, fig. 2a-c. Type locality: "Tham Pratat, Erawan National Park, Kanchanaburi Province, Thailand", hereby emended to: "Doi Chiang Dao, Chiang Mai Province, Northern Thailand".

Type material examined.

Holotype CUMZ Cy 001 (Fig. 8C ), paratypes CUMZ Cy 002 (2 shells; Fig. 8D ), FMNH (1 shell), NHMUK 20200324 (2 shells) and UMMZ (1 shell) 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.

Other material examined.

CUMZ 7427 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 (16 shells; Fig. 6B ) .

Diagnosis.

Shell small (SH up to 2 mm, SW up to 3.2 mm), depressed-conical. Spire ca. 1/6 of shell height. R1 with regular, very strong ribs; R2 shorter than R3; R2 with 44-51 ribs. R3 with prominent, blunt swelling near aperture, anterior slope of swelling steeper than posterior slope. Aperture round. Inner peristome thickened, protruding, with slight parieto-columellar angle. Outer peristome expanded, not reflected. Umbilicus round. Operculum multispiral.

Distribution.

Known only from Doi Chiang Dao, Chiang Mai Province, Thailand.

Remarks.

Re-examination of the type materials (holotype Cy 001: Fig. 8C and paratypes Cy 002: Fig. 8D ) deposited in CUMZ and figured in the original description ( Panha and Burch 1997: fig. 2) revealed that the locality code associated with the types points to "Doi Chiang Dao". However, the locality of the paratypes of Alycaeus pratatensis deposited in SMF (inv. number: 331452) appears as "Tham Pratat, Erawan National Park, Kanchanaburi Province". After we compared all the type materials to the same specimen lots of both localities housed in the general CUMZ collections and communicated with S. Panha, it became evident that the type material might have been mis-allocated. We conclude that the published type locality of A. pratatensis (Tham Pratat, Erawan National Park, Kanchanaburi Province, Thailand) is incorrect, and another species ( Dicharax panhai sp. nov.) lives there. Thus, the type locality of A. pratatensis is hereby amended to Doi Chiang Dao, Chiang Mai Province, Thailand. Páll-Gergely et al. (2020b: 71) transferred A. pratatensis to Dicharax based on the examination of paratype specimens deposited in the Senckenberg Museum ( SMF 331452). However, the present study revealed that those shells and all other CUMZ specimens from Tham Pratat, Erawan National Park, Kanchanaburi Province, Thailand belong to D. panhai sp. nov. (see below).

Figures

Figure 6. Synoptic view of the eight Dicharax taxa in Thailand. A. Dicharax omissus, specimen CUMZ 7426 (gold plated); B. Dicharax pratatensis, specimen CUMZ 7427; C. Dicharax panhai sp. nov., paratype CUMZ 7429 / 2; D. Dicharax pongrati sp. nov., paratype CUMZ 7430 / 2; E. Dicharax notus, specimen CUMZ 7425; F. Dicharax burchi sp. nov., paratype CUMZ 7428 / 2; G. Dicharax borealis sp. nov., paratype CUMZ 5072 / 2; H. Dicharax cucullatus, specimen CUMZ 7421.

Figure 8. A, B. Dicharax omissus A. Syntype NHMUK 1903.7.1.1228; B. Specimen CUMZ 7426 from Tham Mae La Na, Mae Hong Son Province C, D. Dicharax pratatensis C. Holotype CUMZ Cy 001; D. Paratype CUMZ Cy 002 from Doi Chiang Dao, Chiang Mai Province. Close-up images of the aperture not to scale.