Family CALLISTOPLACIDAE

pachylasmae, Chiton (ex G. Seguenza ms.) [ Callistochiton pachylasmae (Monterosato, 1879 ex G. Seguenza ms.)] (Figures 1C, D)

1878c: 77 [XIX: 391]—nomen nudum

1879c: 24 [XXII: 480]—available name

Type material. MCZR–M–12683/H —Holotype “ C. pachylasmae Str. di Messina ! Seg. ms.” “ Chiton pachylasmae Seg. ”

Type locality. Strait of Messina (Mediterranean Sea).

Remarks. Now ascribed to the genus Callistochiton Dall, 1879 ex P. Carpenter ms. It is the type species of the subgenus Allerychiton Dell’Angelo & Oliverio, 1997 (by original designation). The name was made available by a description included in the important paper on Polyplacophora (1879c), but the manuscript name by Giuseppe Seguenza had already appeared as a nomen nudum in Monterosato (1878c: 77) and Tiberi (1879: 150). Gaglini (in Settepassi, 1985) figured the single specimen. Recorded by MolluscaBase (2018) as Callistochiton pachylasmae (Monterosato, 1879) .