Veneridae and Petricolidae 75 



Genus ANOMALOCARDIA Schumacher, 1817 

 Anonialocardiaiis cuneinieris^^*^ (Conrad) PI. 14, fig. 91 



Alt., 12; length, 18; diam., 8.5 mm. Shell small, lengthened and 

 rostrate posteriorly; vari-colored from pure white through shades 

 of brown and green with brown hneations; smooth glossy perio- 

 stracum; umbos small, lunule distmct, esutcheon depressed; prom- 

 inent rounded concentric ridges and suggestions of radiate lines, ex- 

 ternal ligament; interior light purple at posterior margin; pallial 

 sinus small, angular; mner margins crenate. 



Genus PARASTARTE Conrad, 1862 

 ParastarleiiUriquetraiis (Conrad) PI. 14, fig. 92 



Alt., 4; length, 2.75; diam., 2.5 mm. Shell minute, trigonal, 

 equilateral; white or purple with glossy epidermis; umbos high, 

 umbonal region inflated; small lunule, no escutcheon; fine con- 

 centric striations; interior purple or white; pallial line sinuous, 

 margins crenate. 



Family PETRICOLIDAE 



All members of the family Petricolidae are burrowing mollusks. 

 Most of them make for themselves increasingly larger cavities in 

 hard clay, coral, or calcareous rock until adult size is attained. 



Two siphons provide for in- and out-flowing currents of sea 

 water bearing food and oxygen. 



Distribution is general through warm seas. 



The shells are oval-elongate, slightly gaping behind, with an 

 external ligament and two or three cardinal teeth, no laterals; two 

 muscular impressions and a definite pallial sinus. 



Genus PETRICOLA Lamarck, 1801 

 Petrlcola lapicidan^ (Gmelin) PI. 15, fig. 93 



Alt., 20; length, 21 mm. Shell white, rounded, oblique toward 

 posterior angle, thin periostracum; umbos round, recurved; sculpture 



^^s Lat., anomalus, uneven. 

 ^^® Lat., cuneus, a wedge. 



^^^ Gr., prefix, para, beside; Astarte, a genus of mollusks. 

 ^^^ Lat., triquetrus, having three sides. 



1^9 Lat., petra, stone; colere, to inhabit; lapis, rock; cida, suffix meaniag 

 a killing. 



