BULLIDAE 277 



Fa7mly DIAPHANIDAE 

 Genus Diaphiina Brown 1827 



Diaphana minuta Brown Arctic Paper-bubble 



Figure 59b 



Arctic Seas to Connecticut. Europe. 



3 to 5 mm. in length, globose, thin, fragile, and transparent-tan in color. 

 Last whorl globose below, constricted somewhat above. Apex large, globose, 

 obliquely and mammillarly projecting. Suture deep. Columella long, straight, 

 not thickened, the edge partly closing the narrow umbilicus. Moderately 

 common from 6 to 16 fathoms. Diaphana debilis Gould, D. hiemalis Cou- 

 thouy and D. globosa Loven are considered synonyms of this species by 

 Lemche (1948) and other modern workers. 



Family BULLIDAE 

 Genus Bulla Linne 1758 



The names Vesica Swainson 1840 and Bullaria Rafinesque 18 15 have been 

 ill-advisably used for this genus. Fortunately, the name Bulla has been 

 conserved for this group of bubble-shells by the International Commission 

 for Zoological Nomenclature. 



Bulla striata Bruguiere Striate Bubble 



Plate 13P 



West coast of Florida to Texas and the West Indies. 



% to I inch in length, similar to occidentalis, but larger, heavier, and 

 with the spiral grooves well-marked toward the base of the shell and within 

 the apical perforation. The whorls are compressed at the apical end. Colu- 

 mella usually with a brown-stained callus. Locally common. B. amygdala 

 Brug. is probably a smooth form of this species. 



Bulla occidentalis A. Adams Common West Indian Bubble 



Plate 26p 



North Carolina to southeast Florida and the West Indies. 



V2 to I inch in length, smooth, varying from fragile to quite strong, 

 and from cylindrical (young) to fairly swollen. Apex deeply and narrowly 

 perforate. Color very variable, but usually whitish with mottlings, zebra 

 stripes and obscure bands of brown. Surface with numerous, microscopic 

 striations. This is a very common bubble-shell which is found most easily 

 at night and at low tide on grassy, mud flats. The author is often misnamed 

 as "C. B. Adams." 



