200 



TESTACEOUS MOLLUSCA. 



mental edge in the young, nearly straight and subangidated at the 

 extremities. 



U. CoNFERTUs. Lea. Trans. Am. Ph. o. t. 16. f. 47. Trape- 

 zoidal, transverse, inequilateral, inflated, thickish ; beaks slightly 

 elevated and transversely wrinkled, umbones much swollen, liga- 

 ment rather short and thin ; cuticle dark brown, shining, nacre 

 purple or salmon ; cardinal teeth compressed and double in both 

 valves, the lateral long and curved. 1 /o • • 2|-. — S. Carolina.^ 



U. FuLvus. Lea. Tr. Am. Ph. 5. t. 13. /. 39. Icterinus. 

 Con. Narrow elliptical, transverse, inequilateral thinnish, subin- 

 flated, rounded posteriorly, angulated anteriorly, ventral edge entire, 

 dorsal straight, umbonal slope rounded, beaks slightly elevated ; 

 cuticle yellow and yellowish brown, nacre salmon : cardinal teeth 

 oblique, the lateral somewhat curved. -^^ . . \^. — >S. Carolina. 



U. CoNGAR^us. Lea. on U. 1. p. 82. {andTr. Am. Ph. 4.) 

 t. Q. f. 4. Elliptico-rhomboidal, transverse, inequilateral, thin, 

 somewhat flattened at the sides, anteriorly slightly sinuated, the 

 slope and beaks with slight undulations ; ventral edge little rounded; 

 ligament short: cuticle yellow and yellowish brown, with numerous 

 green rays: nacre satinlike and irridescent : cardinal tooth oblique 

 and compressed, the lateral long and enlarged anteriorly. 1 . . If .— 

 S. Carolina. 



U. Declivis, Say. Am. C. t. 35. — U. Geometricus. Say. 

 Transverse, thickish, posteriorly short and rounded, ligamental edge 

 rectilinear very slightly (if at all) elevated and forming a sharp 

 angle with the anterior edge which runs down obliquely to the 

 entire and but slightly rounded ventral edge : umbonal slope not 

 elevated ; surface deeply wrinkled : inside just tinged with pur- 

 plish ; cardinal teeth oblique, the lateral distant, rectilinear, oblique. 

 2j. — N. America. 



U. Blandingianus. Lea. Tr. Am.Ph. 5. t. 15. /". 44. Sub- 

 trapezoidal, transverse, very inequilateral, thin : beaks somewhat 

 prominent : cuticle fuscous, wrinkled, nacre dull purple : cardinal 

 teeth compressed, the lateral long and curved. 1^^ . . 2-^%. — Florida. 



U. Depressus. La7n. 38. — D'Orb. — Lesson, voy. de Coq. t. 

 lo.y". 55? Ovate-oblong, depressed, thin, rounded at the extremi- 

 ties of the sides : cuticle brown, nacre bluish. 2. — New Holland. 



U. Angustus. Lam. 42. — an List. t. 147. f. 3. Transversely 

 oblong, narrow, subsinuated, anteriorly with two obsolete angles, 

 extremities of the sides rounded ; cuticle yellowish brown, slightly 

 striated longitudinally on the depression in the middle. 2f." 



1 Add likewise the U. Paliatus of Ravenel's letter, and the U. 

 -C-/ Waterensis of Lea, the Raven|li of Conrad. 

 ' 2 Add likewise the U. Modestus of Ferussac. 



