1G2 . VOLUTIDiE. 



Family YOLUTID^. 



Shell turreted, aperture notched in front, columella obliquely 

 plaited ; no operculum in the larger species. Animal with 

 recurved siphon, foot very large, partly hiding the shell, eyes 

 on the tentacles or near their bases. Dentition (x, 7). 



Cymbium, Klein. 



Boat-shell. Syn. — Yetus, Gray. 



Distr. — 5 sp. W. Mediterranean, W. Coast of Africa. C. 

 prohoscidale. Lam. (liii, 4; i, 15). 



Shell oval-oblong, ventricose, thin ; spire short, nucleus large, 

 globular, forming an obtuse papillary apex ; whorls few, forming 

 k flat edge around the nucleus; aperture oblong, wide; colvimella 

 with several oblique plaits ; outer lip thin, simple. 



The animal is large, compared to the size of the shell, when 

 expanded. The foot partially covers the shell, which is sunk 

 into its substance. There is no operculum. Ovoviviparous,the 

 young when born being of a large size and covered with a shell 

 with a large irregular callous apex. Thej^ leave the parent 

 when they have attained a length of about an inch, the brood 

 appearing to consist of four or five individuals. Adanson 

 observes that the high winds of April cast the " yet" up in such 

 vast quantities as sometimes to cover the shore, the natives of 

 Senegal using them as food. 



Cymbium is separated from Melo by its flat or slightly chan- 

 neled shoulder and want of coronal spines. When fresh, the 

 epidermis is more or less covered by a thin glaze deposited by 

 the enveloping mantle. 



Melo, Humphrey. 



Bistr. — 10 sp. Indian Ocean, Australia, etc. 31. tessellata, 

 Lam. (liii, 5). 



Shell large, subovate, ventricose, thin ; spire short, apex 

 obtuse, papillary, persistent; whorls smooth, the last posteriorly 

 coronated; aperture oblong, wide; columella with several oblique 

 plaits, the anterior the largest ; outer lip simple, acute, obliquelj'- 

 truncate in front. No operculum. 



The apex of the shell is spiral, regular, very diff'erent from the 

 shapeless apex of Cymbium, This genus, like Cymbium, is 

 ovoviviparous, the young ones being arranged in the oviduct of 

 the female in a long string, without egg-shells. 



YoLUTA, Linn. 



Syn. — Yolutolyria, Crosse. Scaphella, Swains. Scapha, Gray. 



Bistr. — About 75 sp. Indian Ocean, Japan, Alaska, Australia, 

 Eastern Polynesia, Atlantic Coasts of Southern South America, 

 to West Indies, Southern Africa, etc. No species exist in the 



