Cylichna modesta Thiele, 1925

Jirapatrasilp, Parin, Cuny, Gilles, Kocsis, László, Sutcharit, Chirasak, Ngamnisai, Nom, Charoentitirat, Thasinee, Kumpitak, Satapat & Suraprasit, Kantapon, 2024, Mid-Holocene marine faunas from the Bangkok Clay deposits in Nakhon Nayok, the Central Plain of Thailand, ZooKeys 1202, pp. 1-110 : 1-110

Cylichna modesta Thiele, 1925

Figs 4 R , 10 B

Cylichna modesta Thiele, 1925: 241–242 [275 – 276], pl. 44 [32], fig. 7. Type locality: “ Neu-Amsterdam ”, Station 167 (37 ° 47 ’ südl. Br., 77 ° 33.7 ’ östl. L., 496 m). Swennen et al. 2001: 137, fig. 497. Wells et al. 2021: 144.

Adamnestia modesta . Robba et al. 2004: 230, pl. 34, fig. 5 a, b. Robba et al. 2007: 97 (appendix). Negri et al. 2014: table 3.

Referred material.

CUF - NKNY - G 39 (11 shells; Figs 4 R , 10 B ).

Habitat.

Sublittoral in muddy or fine sandy bottoms ( Robba et al. 2004).

Distribution.

Southwest Pacific. Records of fossils from the Holocene in Thailand ( Robba et al. 2004).

Record in Thailand.

Gulf of Thailand ( Wells et al. 2021).

Taxonomic remarks and comparisons.

This species differs from its similar species, Cylichna sibogae Schepman, 1913 , by having a less slender shell and an adapical umbilicus unbounded by sharp angulation ( Robba et al. 2004). The generic assignment to either Adamnestia Iredale, 1936 or Cylichna requires further investigation.

Subcohort Panpulmonata Jörger et al., 2010

Superorder Eupulmonata Haszprunar & Huber, 1990

Order Ellobiida Van Mol, 1967

Superfamily Ellobioidea Pfeiffer, 1854

Figures

Figure 4. Size comparison of gastropods found in this study A Brunneifusus ternatanus B Murex trapa C Indothais lacera D Pristiterebra miranda E Chicoreus capucinus F Indothais gradata G Ellobium aurisjudae H Inquisitor vulpionis I Turricula javana J Architectonica perdix K Pseudoneptunea varicosa L Cassidula nucleus M Pseudoetrema fortilirata N Paradrillia melvilli O Duplicaria tricincta P Granuliterebra bathyrhaphe Q Comitas ilariae R Cylichna modesta S Maoritomella vallata.

Figure 10. Gastropods and bivalves. A Duplicaria tricincta B Cylichna modesta C Jupiteria puellata D Saccella mauritiana.