234 MANUAL OF THE MOLLTJSCA. 



Bisfribution, 30 species. Greenland, Britain, West Indies^ 

 Cape, Australia, Pacific, West America. 



Erato, Eisso. j 



Etymology, Erato, tlie muse of love-songs and mimicry. 

 Type, E. Icevis, PI. YII., Eig. 24. 



Shell minute ; like marginella ; lips minutely crenulated. 

 Animal like trivia. 



Distribution, 11 species. Britain, Mediterranean, West Indies, 

 China. 

 Fossil, 2 species. Miocene — . France, Britain (Crag). 



OvTJLTJM, Lam. 



Etymology, diminutive of ovum, an egg. 



Synonym, Amphiceras, Gronov. 



Types, 0. Ovum, PI. YII., Fig. 25. 0. gibbosa and verrucosa. 



Shell like cyprcea ; inner lip smooth. 



Distribution, 36 species. Warm seas. West Indies, Britain, 

 Mediterranean, China, West America. 



.Fossil, 11 species. Eocene — . France, &c. 



Suh-genus. Calpurna, Leach. 0. volva (" the weaver's 

 shuttle"). Apertui-e produced into a long canal at each end. 

 Foot narrow, adapted for walking on the round stems of the 

 gorgonice, &c., on which it feeds. C. patula inhabits the south 

 coast of Britain, it is very thin, and has a sharp outer lip. 



Calpurnus,- Montfort (name) = Ovulum verrucosum. 



Volva (Fleming) = Ovulum patulum {Calpurna, Leach). 



Radius (Montfort) Schum. = Ovulum volva 



Section B. Holostomata. Sea-Snails. 



Shell spiral or limpet-shaped ; rarely tubular or multivalve ; 

 margin of the aperture entire ; operculum, horny or shelly , 

 usually spiral. 



Animal with a short non -retractile muzzle ; respiratory siphon 

 wanting, or formed by a lobe developed from the neck (Fig. 68), 

 gills j^ectinated or plume-like, placed obliquely across the back, 

 or attached to the right side of the neck ; neck and sides fre- 

 quently ornamented with lappets and tentacular filaments. 

 Marine or fresh-water. Mostly phytophagous.* 



* Tliese "sections" are not very satisfactory, but they are better than any others 

 yet proposed, and they are convenient on account of the great extent of the order 

 -iroso-bratichiafa. Natica and scalaria have a retractile proboscis. Pirena has a 



Hched aperture, and aporrhais, a canal, 



