OF MOLLUSCA. 



73 



c. Mouth narrowish ; the outer lip arched; the ribs enlarged or 



tubercular near the dorsal groove. 



3. T. pulex. 



d. Mouth narrow ; ribs tubercular ; dorsal line distinct ; front of 



columella smooth. 



4. T. pustulata. 



The branchial plume of Trivia europcea 

 is a large, finely pectinated, half-moon-shaped Fig. 41 . — Trivia europcea. 

 plate of two segments, each appearing to 

 have a branchial artery. The male organ is 

 large, spatulate, folded. 



Mr. Clark (Mollusca, 505) describes 

 Trivia europcea " as having a long proboscis, 

 which can be exserted, though it is rarely 

 seen," and which has not been observed in 

 the larger Cowries (Cyprcea). Dr. Loven, 

 who specially examined the mouth of C. 

 helvola and C. europcea, describes the ros- 

 trum as short, prominent, and not retractile. 



Central tooth of Trivia europcea longer 

 than broad, cutting edge subtriangular, den- 

 ticulate on each side, with a sharp lobe in 

 the middle ; lateral teeth dissimilar ; the 

 first at the tip with a long point, denticulate 

 on each side ; second and third simple, 

 claw-like. — Loven (see fig. 41). 



5. Ltjponia. 



Shell pear-shaped, smooth, or cross-ribbed ; mouth linear ; front 

 end of the columellar lip crossed by several irregular ridges, without 

 any distinct marginal one, internally narrow, fiat. 



1 . L. Algoensis. 



6. CyprjEovula. 



Shell pear-shaped, smooth, or cross-ribbed ; mouth linear ; spire 

 hidden ; front end of columella covered with regular cross ribs, like 

 rest of base, internally produced into an acute-toothed ridge. 



1. C. Capensis. 



Shell finely cross-ribbed. 



2. C. umbilicata, Sow. 



** Shell smooth. 



7. Erato. 



Spire conical ; apex submamillary, blunt ; shell, when young, 

 smooth ; the adult with both lips finely crenulated ; the columella 

 concave, slightly radiately plaited or smooth, with two or three folds 



