308 TROCHID^. 



subumbilicated, the umbilical region callous. Operculum flat- 

 tened, with a depressed marginal line. East Indies. I. irium- 

 phans^ Phil. (Ixxx, 26). 



UVANILLA, Gray. Shell trochiform, conical, with moderately 

 elevated spire ; base concave, not umbilicated ; whorls flattened, 

 rugose, spinously fringed. Operculum with two convex ribs, 

 one nearly parallel to the margin, the other arcuated, subcentral. 

 5 sp. Australian seas. I. fimbriata, Lam. (Ixxx, 30). 



PACHYPOMA, Grray. Like TJ vanilla, but base of the shell more 

 concave. Operculum oval, subquadrangular, externally convex. 

 '7 sp. West Indies, Brazil. /. caelata, Chemn. (Ixxx, 31). 



LiTHOPOMA, Gray. Shell turbinated, not umbilicated, spire 

 moderate, whorls with oblique longitudinal ribs and nodules ; 

 inner lip concave, subtrnncated in front, and with a longitudinal 

 shallow channel. Operculum oval, thick, granulous externally, 

 and flattened at the margins. "West Indies. /. tuber, Linn. 

 (Ixxx, 32.) 



POMAULAX, Gray. Shell trochiform, elevated conic, angulated 

 and nodose at the periphery, obliquely ribbed, not umbilicated ; 

 inner lip arcuated, with a wide callus, which is channeled, ante- 

 riorly truncated. Operculum with three radiating ribs and 

 perforated axis. T sp. North Pacific, America and Japan. /. 

 undosa, Wood (Ixxx, 33). 



COOKIA, Lesson. Shell turbinated, not umbilicated ; whorls 

 nodulous ; coiumellar lip with a wide flattened callus and spiral 

 shallow excavation. Operculum oval, flat, smooth, with a large 

 snbspiral, submarginal rib. New Zealand. I. Gookii, Chemn. 

 (Ixxx, 34). 



BOLMA, Kisso. (Tubicanthus, Swn.) Shell turbinated, not 

 umbilicated, rugose or tuberculated,with deep suture; aperture 

 round ; inner lip wide, callous, concave. Operculum with a 

 subcentral tubercle and spiral rib. 3 sp. Mediterranean Sea, 

 China, Japan. /. rugosa, Linn. (Ixxx, 35). 



Family TKOCHID^. 



Shell usually conical, with flattened base, nacreous inside. 

 Operculum corneous, multispiral. 



Animal like that of Turbinidss (p. 304). Differs from that 

 family in its conical shell (usually) and its operculum ; that of 

 Turbinidse being calcareous and paucispiral. Dentition (xii, 46). 



Delphinula, Lam. 

 Etym. — Diminutive of Delphiniis, a dolphin. 

 Syn. — Angaria, Bolten. 



Distr. — ^20 sp. Eastern tropical seas. D. melacantha (Ixxx, 

 36). Fossil. Jurassic — . 



Shell orbicular, depressed ; whorly few, angulated, rugose, or 



