296 AmericaJi Seashelh 



Genus Cavolina Abildgaard 1791 



Shell squat, bulbous, horny-brown in color, characterized by a much 

 constricted aperture, which is, however, very broad transversely. Sides of 

 shell often prolonged into spine-like projections. Cavolinia is an alternate, 

 incorrect spelling, and Hyalaea Lamarck is a synonym of this genus. 



Cavolina lojigirostris Lesueur Long-snout Cavoline 



Figure 64V 



Worldwide, pelagic. (47° N. to 40° S.). 



5 to 9 mm. in length. Dorsal lip with a thin margin. Posterior portion 

 of the ventral lip markedly projecting laterally. Common. Hyalaea li?nbata 

 Orb. and H. angiilata Souleyet are synonyms. 



Cavolina gibbosa Rang Gibbose Cavoline 



Figure 64\v 



Worldwide, pelagic. (43° N. to 38^ S.). 



About 10 mm. in length. Dorsal lip with a thin margin. Shell without 

 appreciable lateral points. Ventral lip not more developed than the dorsal. 

 Ventral surface with an anterior transverse keel. Common. 



Cavolina tridentata Forskal Three-toothed Cavoline 



Figure 64U 



Worldwide, pelagic. (40° N. to 40° S.). 



10 to 20 mm. in length. Dorsal lip with a thin margin. Ventral Hp not 

 more developed than the dorsal one. Shell without appreciable lateral points. 

 The shell is as broad at the end of the lips as it is at the anterior end. C. 

 gibbosa is narrower at the ends of the lips. Hyalaea afflnis Orb. is merely a 

 form of this species. C. televms Linne might possibly be this species. 



Figure 64. The Pteropods or Sea-hut- Pelseneer;m,0/i7(?n77JCo/z/7;777e//irRang; 

 terflies of American Waters, a, Spira- n, Creseis aciciila Rang; o, Styliola sub- 

 tell a helicina Phipps; b, 5. lesuenri Orb.; zila Q & G; p, Creseis virgula Rang; q, 

 c, 5. retroversa Fleming; d, 5. biilnnoides Hyalocylis striata Rang; r, Cavolina i?i- 

 Orb.; e, S. trochiformis Orb.; f, Peracle fJexa Lesueur; s, Cavolina qiiadridentata 

 bispinosa Pelseneer; g, Peracle reticidata Lesueur; t, C trispinosa Lesueur; u, C. 

 Orb.; h, Spiratella infiata Orb.; i, Clio tridentata Forskal; v, C longirostris 

 cuspidata Bosc; j, Clio reciirva Children; Lesueur; w, C. gibbosa Rang; x, C. im- 

 k, Clio pyramidata Linnc; 1, Clio polita cinata Rang. 



