427/583 -- Shell orbicular, nearly trochi-form, white with two pale-brown bands on each whorl; the one near the suture narrow, and the other, placed on the middle of the whorl, broad; whorls five; convex rounded, with numerous close concentric furrows; axis umbilicated; umbilicus rather narrow, deep; aperture rather more than one half the length of the shell; peristome (not formed ?) simple. Chiton rugosus (n.s.) Testa octovalvis glabra, valvis tuberculatis, ligamento glabro laevi. -- Shell with eight valves, bald; valves covered with numerous small tubercles both on the central and lateral area; marginal ligament smooth, bald. 11 179. |