LITTORINIDAE 131 



Shell smooth except for microscopic, spiral scratches. Color light-tan to 

 brown with the spire tinted with purplish rose. Often confused with Litiopa 

 which has a blade-like ridge on the columella just inside the aperture. Com- 

 mon from low water to 25 fathoms. Alias L. divaricata Fab. and solidula 

 Loven. 



Lacuna unifasciata Carpenter One-banded Lacuna 



Figure 36b 



Monterey, California, to Lower California. 



^ inch in length, moderately fragile, similar to the other Lacunas, but 

 characterized by its very narrow, long, chink-like umbilicus and by the 

 carinate periphery of the whorl which bears a fine, dark-brown spiral line. 

 Early whorls usually pinkish, remainder yellowish tan. Umbilicus and colu- 

 mella white. The peripheral carina may be weak or obsolete, and the color 

 line may consist of a series of faint, slanting streaks of light reddish brown. 

 Very common in littoral seaweed and kelp in southern California. 



Lacuna carinata Gould Carinate Lacuna 



Figure 36a 

 Alaska to Monterey, California. 



% to ^ inch in length, 3 to 4 whorls, moderately fragile. Aperture 

 semi-lunar, large. Outer lip thin. Columellar chink large, long and white. 

 Shell smooth, chalky-white, but always covered by a thin, yellowish brown, 

 smooth periostracum. Common on kelp weed. L. porrecta Cpr. and striata 

 Gabb are the same. Do not confuse with vincta which has a higher spire and 

 much narrower, brownish-tan umbilical chink. 



Lacuna variegata Carpenter Variegated Lacuna 



Puget Sound, Washington, to Santa Monica, California. 



M inch in length, similar to unifasciata, but having a very deep umbilical 

 chink which is bordered by a sharp ridge. The spiral carina at the level of 

 the suture is very small, but quite sharp. The yellowish tan shell has mot- 

 tlings or oblique bands of darker color. Moderately common in eel-grass 

 along the shore. 



Fcrmily LITTORINIDAE 

 Genus Haloconcha Dall 1886 



Haloconcha reftexa Dall Reflexed Haloconch 



Alaska and the Bering Sea. 



% inch in length, fragile, 3 whorls; body whorl large. Resembles a Vel- 



