UNIVALVE MOLLUSKS 121 



if it had been turned in a lathe, and it cer- 

 tainly is dainty enough for a fairy's bolster. 

 The color is brownish, and fresh specimens 

 are banded with numerous microscopic stride. 

 Large specimens are nearly an inch long. Fig. 93 



l^ornatina harpa^ Dall, the Harp Lathe- 

 shell, is smaller, being about six millimeters in 

 length. The color is white, and it is easily dis- 

 tinguished by the presence of longitudinal grooves 

 and lines on the upper half of the last whorl. 



I^ornatina eximia, Baird, the Excellent Lathe-shell, 

 resembles Figure 93, though it is smaller. It differs 

 in having a more depressed spire, a longer and nar- 

 rower aperture, and a smaller plait on the colum- 

 ella. It is found in Puget Sound, and also at San 

 Diego. 



^ornatina cerealis^ Gld., the Grain Lathe-shell, 

 has a minute white shell, less than a quarter of an 

 inch in length. It is quite solid, and has a spire 

 rounded at the apex. 



Cylichna alba^ Brown, the White Cup-shell, is an- 

 other of these small species of shells which resemble 

 little rolls of cloth. This species has a white shell, 

 10 mm. long, which is somewhat cylindrical and 

 which tapers towards either end. It occurs on the 

 coast of southern California and also on the Atlantic 

 shores. 



Volvula cylindrical Cpr., the Roll-shell, resembles 

 the last species, but is somewhat flattened in the mid- 

 dle and has an extended umbilical point, "Like a 

 grain of rice, pointed at one end." — Cpr. 



The fine shell shown in Figure 94 is named Bulla 



