Sanguinolariidae 87 



inequilateral, somewhat wedge-shaped; umbos low, at summit of 

 posterior slope, directed backward; external ligament behind umbos; 

 elongate anteriorly, short and slightly truncate posteriorly; con- 

 centric growth lines and fine radiate stnations which become strong 

 and elevated over posterior area; cardinal and lateral teeth present; 

 interior smooth, faintly colored, margins finely crenate. 



The range of color of Donax is remarkable. White and green, 

 shades of red, brown, lavender, purple, and yeJlow, variously rayed 

 and plaided make the shells among the most colorful objects upon 

 the beach. 



Family SANGUINOL A KIIDAE 



The mollusks of this family were formerly placed among the 

 Tellinas, with which group their range, habits, and shells suggest 

 kinship, but anatomical differences rank them independently. The 

 group has world-wide distribution m shallow and moderate depths. 



Like the Tellinas and Semeles the animals have long siphons, a 

 strong foot, and bury themselves m sandy sea bottoms. 



Genus TAOELUS Gray, 1847 

 Tagelus plebeius^so (Solander) {T. gibbus Spengler) PI. 17, fig. 110 



Alt., 16; length, 43; diam., 7.5 mm. Shell equivalve, subequi- 

 lateral, subcylindrical, elongate; white, smooth, with glossy, brownish 

 periostracum; umbos postcentral, suppressed; dorsal and ventral 

 margins nearly parallel and in contact only opposite umbonal 

 region; anterior and posterior margins bluntly rounded, gaping; 

 cardinal, but no lateral teeth in each valve; interior white, polished, 

 duplex muscular impressions; deep pallial sinus. 



Littoral zone to moderate depths. 



Tag'eliis (livisus^^i (Spengler) PI. 17, fig. Ill 



Alt., 15; length, 38; diam., 6.5 mm. Shell with general characters 

 of T. plebeius, slightly more slender, with a slight concavity in middle 

 of ventral margin; shell light-colored, rayed with purple. A strong 

 central ray indicates position of a nearly obsolete internal rib; in- 

 terior purplish, polished. 



Littoral zone to moderate depths. 



150 Lat., plebeius, common.; gibbus, hump. 



151 Lat., dividere, to divide. 



