160 American Se ash ells 



Yi inch or less in length, slightly fusiform with very slightly convex 

 sides to the spire. Suture almost impossible to see. Color glossy yellow-brown 

 with 2 rows of glassy, whitish, rounded beads. A third much weaker row 

 of beads, or an additional spiral thread, may appear in the last 2 or 3 whorls. 

 Axial threads connecting the beads are weak and form small pits. Fairly 

 common under stones along the low-tide zone. 



Family JANTHINIDAE 



Genus Janth'ma Roding 1798 



Subgenus Janthina s. str. 



Janthina janthina Linne Common Purple Sea-snail 



Plate 4) 

 Pelagic in warm waters; both coasts of the United States. 



I to 1/4 inches in diameter. Whorls slightly angular. Two-toned, 

 with purplish white above and deep purplish violet below. Outer Hp very 

 slightly sinuate. Common after certain easterly blows along the south- 

 eastern United States, especially from April to May. This is /. fragilis 

 Lamarck. 



Subgenus Violetta Tredale 1929 

 Janthina globosa Swainson Globe Purple Sea-snail 



Plate 4k 



Cast ashore along both coasts of the United States. 



/4 to % inch in diameter. Whorls globose, well-rounded. Color violet 

 throughout. Outer lip very slightly sinuate. Not very common. 



Subgenus Jodina Morch i860 

 Janthina exigua Lamarck Dwarf Purple Sea-snail 



Plate 4I 



Cast ashore in most warm seas. 



% inch in length. Whorls slightly flattened from above. Outer lip with 

 a prominent notch. Light-violet, banded at the suture. Fairly common. 

 /. bifida Nuttall is probably this species. 



NOTE 



Superfamily PYRAMIDELLACEA 



The families Pyrafiiidellidae, Aclididae, Eulimidae, Styliferidae and 

 Efitoconchidae, most of which are small parasitic gastropods, have in the 

 past been placed here among the prosobranchs, but are now considered to 



