Amphicutis, Pomory, Christopher M., Carpenter, Jerry H. & Winter, John H., 2011

Pomory, Christopher M., Carpenter, Jerry H. & Winter, John H., 2011, Amphicutis stygobita, a new genus and new species of brittle star (Echinodermata: Ophiuroidea: Ophiurida: Amphilepididae) found in Bernier Cave, an anchialine cave on San Salvador Island, Bahamas, Zootaxa 3133, pp. 50-68 : 53-54

Amphicutis gen. nov.

Diagnosis. Disk with imbricating scales on dorsal and ventral surface ( Fig. 3 ). Radial shields oval, on disk edge, separated medially along their entire length by one column of disk scales. Second tentacle pore of oral frame outside mouth slit. Genital scales flat and thin, no bursal sacs. Ventral tooth at the apex of each jaw broadly rounded. Proximal oral papillae small rounded, in infradental position. Distal oral papillae oblong, closing off mouth slit with distal oral papilla on adjoining jaw. Small oral papilla sometimes present between infradental and distal papillae. Non-madreporite oral shields small ovals, similar in appearance to disk scales, madreporite distinct. Adoral shields narrow, curved, thin, not tightly fused to oral plates or oral shield. Translucent layer of skin raised above surface of arms in life, usually visible in preservation. Disk and arms often formed mainly by soft tissue outlining plates and scales, but lacking significant calcification.

Type Species. Amphicutis stygobita sp. nov.

Etymology. Name of the new genus is Latin, feminine derived from amphi, around, and cutis, skin.

Remarks. The new genus is distinguished from Amphilepis , the only current genus in the family Amphilepididae , by the 1) oral shields (distinctly separate from disk scales, and triangular in shape with a broad distal edge in Amphilepis ), 2) adoral shields-oral shield union (tightly fused and thicker than disk scales forming the more typical oral frame of ophiuroids in Amphilepis ), 3) oral papillae (two papillae per side with the proximal papilla set more to the side than infradental in Amphilepis ), 4) skin (lack of pronounced soft tissue in Amphilepis ), and 5) ventral tooth (triangular in Amphilepis ). See Mortensen (1927) and Mills and O’Hara (2010) for good illustrations of Amphilepis .

Figures

FIGURE 3. Amphicutis stygobita gen. nov., sp. nov. A, dorsal view disk. B, ventral view disk. C, ventral view arm. D, dorsal view arm. E, side view arm. F, dorsal view arm tip.