Robustaurilla assimilis (Kayiyama, 1913)

Ji, Su-Jung, Jung, Chuleui, Bang, Hyun Woo, Song, Min Ok, Jung, Jongwoo, Yoon, Seong Myeong, Lee, Seunghwan, Keum, Seoyoung, Yang, Hee-Min, Lee, Dongmin, Lee, Geon Hyeok, Oh, Jaeseok, Kim, Kichoon, Park, Hansol, Moon, Heejin, Joharchi, Omid, Kang, Yeseul, Eom, Keeseon S., Lee, Kyung Jin, Eun, Ye, Kim, Taeho, Karanovic, Ivana, Lee, Jeounghee, Choe, Seongjun & Min, Gi-Sik, 2023, Unrecorded species of Korean invertebrates discovered through the project of ‘ Discovery of Korean Indigenous Species’ II, Journal of Species Research 12 (1), pp. 68-89 : 83

32. Robustaurilla assimilis (Kayiyama, 1913) ( Fig. 32 )

ffi대AEŜýẫŦDḄḤṆḇNj (ṵAE)

Cythereis assimilis Kajiyama, 1913 .

Mutilus assimilis ( Kajiyama, 1913) Ishizaki (1968) .

Robustaurila assimilis ( Kajiyama, 1913) Yajima (1982) .

Material examined. Bongam-ri (34°59.629′N, 128° 26.198′E), Gyeongsangnam-do, Korea; collected by I Karanovic on 31 March 2013.

Deposition. NIBRIV0000835142.

World distribution. Japan and Korea.

Diagnosis. Size about 1.2 mm. Surface pitted coarsely and irregularly. The pits, except in the middle area, often disappearing. Anterior marginal ridge strong, parallel to anterior margin. Ventral marginal ridge strong. Radiate ridges also strong.

Valves asymmetrical. Left valve sub-quadrangular in lateral view; greatest height at anterior third. Dorsal margin slightly convex, descending backward, with distinct process postero-dorsally. Anterior margin broadly and distortedly rounded. Posterior margin concave above, convex below, with some denticles, the lowest one of which is most prominent. Ventral margin almost straight. Right valve lower than the left.

Remarks. The genus Mutilus differs from the genus Aurila only in having strong ornamentation on the surface. No difference in soft parts is found between both genera. Future revisions are necessary and will probably lead to synonymyzation of the two genus names.

Figures

Fig. 32. Robustaurila assimilis (Kayiyama, 1913). Right valve.