12 CYLICIINID.E. 



Genus DIAPHANA, Brown. 



Head-disk broad and short; tentacular lobes short, 

 conical, lateral, wide apart ; eyes immersed in their hind 

 bases. Mantle-margin slightly thickened. Foot short, 

 bi-lobed behind. 



Shell thin, hyaline, sub-umbilicated, inflated, ovate 

 or sub-globose ; spire depressed, with a mamillated nu- 

 cleus ; aperture expanded, not extending beyond the 

 body-whorl ; columella reflexed and sinuous ; outer lip 

 sinuous, produced anteriorly. 



Syn. Amphisphyra, Loven. 



Ex. D. hyalina, Turton, pi. 56, fig. 8. Shell, D- 

 hyalina, fig. 8, a. 



In this genus, as in the Rissoella of Gray, the eyes are 

 placed far back behind the head, so that in order to 

 render the vision of the animal distinct, the shell is 

 nearly transparent. The head of the animal is very 

 short, and the tentacles wide and far apart. The species 

 are few in number, and have been observed in the British, 

 American, and Scandinavian Seas. 



Species of Diaphana. 



debilis, Gould. Gouldii, Couth. 



globosa, Loven. hyalina, Txirt. 



Genus TORNATINA, A. Adams. 



Head sub-trigonal ; tentacular lobes lateral, triangular, 

 recumbent, with the eyes sessile on their front bases. 



