Ceramaster Verrill, 1899

Verrill, 1899: 161 [as Tosia (Ceramaster)]

Fisher, 1906: 1054; 1911: 162, 204; Verrill, 1914: 289; Koehler, 1924: 173; Mortensen, 1927: 80; Djakonov, 1950: 38; Tortonese & A.M. Clark, 1956: 347; Halpern, 1970b: 62; 1970c: 212; 1970: 62; Downey, 1973: 49; McKnight, 1973: 178; Downey, 1973: 49; A.M. Clark & Courtman-Stock, 1976: 61; Downey in Clark & Downey, 1992: 231; A.M. Clark 1993: 247; H.E.S. Clark & McKnight 2001: 32, Mah 2011: 5 (as Ceramaster)

Koehler, 1909: 78 [type species Pentagonaster (Philonaster) mortenseni Koehler, 1909] (as Philonaster) Verrill, 1914: 292 (As Tosiaster)

Comments. Several issues surround the genus Ceramaster, including uncertainty regarding its monophyly and overlap with such genera as Peltaster (Mah 2011) .

I argue that species described herein most closely resembles the type species, C. grenadensis and share several fundamental synapomorphies, including the presence of wide (W>L) inferomarginal plates, strongly abactinal facing superomarginal plates, and a flattened, pentagonal body shape (R/r<2.0). These characters serve to separate C. clarki, C. grenadensis, C. japonicus, C. leptoceramus, C. smithi and C. pointsurae n. sp. from Bathyceramaster .

Descriptions of some Ceramaster sp., including Ceramaster glasbyi McKnight 1993 display a more stellate shape and lack fasciolar grooves. These will need to be considered more thoroughly pending an overview of the 16 species nominally assigned to Ceramaster .