508 MOLLUSCA 



FAMILY 1. AUBICULIDAE. 



Shell spiral with a horny periostracum ; lower whorl usually very 

 large with an elongated aperture which has folds on the parietal wall and 

 usually teeth on the outer lip; head projects snout-like in front of the 

 cylindrical tentacles: several hundred species, which live largely in salt 

 marshes, principally in tropical countries; about 20 American species. 



Key to the genera of Auriculidae here described : 



d Spire of shell at least as long as its aperture. 



6j Shell not minute 1. PHYTIA 



6 a Shell minute 2. CABYCHIUM 



o. Spire much shorter than the aperture 3. MELAMPUS 



1. PHYTIA Gray. Shell conical with a pointed spire; aperture with 

 1 to 5 teeth on the parietal wall; jaw slightly arched, smooth, with a 

 slight median projection; foot with a transverse groove: several species, 

 principally Mediterranean, 1 American. 



P. myosotis (Draparnaud) (Fig. 773). Height 8 mm.; diameter 4 

 mm.; horn-color with a reddish sutural line: marine; Nova Scotia to 



Fig. 773 Fig. 774 Fig. 775 



Fig. 773 Phytia myosotis (Verrill). Fig. 774 CarycMum exiguum (Baker). 

 Fig. 775 Melampus lineatusa. banded individual (Verrill). 



Chesapeake Bay, also at San Francisco, near high-water mark along the 

 shore, being common in crevices of wharfs; an European species, perhaps 

 imported. 



2. CAEYCHITTM 0. F. Miiller. Shell very thin and like a Pupa in 

 form; aperture oval with 1 or 2 teeth on parietal wall; jaw smooth: 

 about 15 species, principally European; terrestrial. 



0. exiguum (Say) (Fig. 774). Height 1.75 mm.; diameter .75 mm.; 

 color of shell white, with 4 l / 2 whorls: under and in logs and moss in 

 moist places in eastern and central states; Oregon; common. 



3. MELAMPUS Montfort. Shell with a very short, blunt spire and a 

 very large lower whorl; aperture long and narrow; inner lip with 

 several transverse folds; outer lip acute: 120 species, mostly tropical; 

 amphibious or found in brackish water; 4 American species. 



M. lineatus Say (Fig. 775). Shell 13 mm. long and 7 mm. thick, 

 horn-color or reddish-gray, with 4 or 5 revolving bands when young, 

 aperture with a white callus and a prominent tooth on the parietal wall : 

 among the grass of salt marshes, near high- water line, from New England 

 to Texas; common. 



