FAMILY TELL IN ID.E DONAX. 211 



T. interstriata. (Id. lb. Vol. 5, p. 218.) Subovate, angulated at the anterior base, transversely 

 wrinkled and slightly striated within longitudinally : hinge teeth very small ; no lateral teeth. 

 Color, white, immaculate. Length, 1*6; breadth, 2" 1. East-Florida. 



T. alternata. (Id. lb. Vol. 2, p. 275.) Shell compressed, oblong, narrow and angulated before: 

 numerous impressed concentric lines, alternately obsolete, on the anterior margin. Within, a cal- 

 lous line passes from behind the hinge to the inner margin of the anterior cicatrix. Anterior hinge- 

 tooth emarginate; posterior lamellar tooth near the cardinal, so as to appear like a primary tooth; 

 that of the right valve wanting : anterior lamellar tooth at the extremity of the ligament. Anterior 

 hinge-slope declining in a concave line to an obliquely truncated tip. Color, white, tinged with 

 yellow within. Length, 1*25; width, 2 • 2. Georgia and East-Florida. 



T. decora. (Id. lb. Vol. 5, p. 219.) Transversely subovate, not much compressed, with numerous 

 minute concentric wrinkles and regular equidistant lines crossing them : no oblique lines on the 

 anterior margin. Posterior lateral tooth of the left valve prominent; the others obsolete: apex a 

 little before the middle. Color, rosaceous or white, with rosaceous radiations. Length, 8-5; 

 breadth. • 8. East-Florida. 



T. mera. (Id. Am. Conch.) 



GENUS DONAX. Linnceus. 



Animal with large labial appendages : mouth small. Foot compressed, trenchant, angular. 

 Tubes or siphons elongated, slender and separate, entering into a fold of the mantle. 

 Shell transverse, equivalve, inequilateral, trigonal : two primary teeth in one or both valves, 

 and one or two lateral teeth more or less apart. Ligament short, external. 



DONAX FOSSOR. 



PLATE XXIII. FIG. 555. 



(STATE COLLECTION.) 



Donax fossor. Say, Jour. Acad. Nat. Sciences, Vol. 2, p. 306. 



Description. Shell subtriangular ; anterior margin short and rounded. Posterior hinge- 

 slope straight ; the base very slightly prominent beyond a regular curve at the middle. 

 Surface striated with numerous equal parallel lines, not visible to the naked eye, and obso- 

 lete on the posterior margin ; the basal margin crenate within. 



Color. Pale livid, with two longitudinal rays both within and without. 



Length, 0-43; width, 0"5. 



This pretty little shell, which is moderately abundant at the south, is not uncommon on our 

 coast, but does not seem to extend northwardly. It buries itself in the sand, and affords a 

 supply of food to birds and fishes. 



27* 



