182 TESTACEOUS MOLLUSCA. 



ing almost the whole disc, nacre milk white : cardinal teeth rather 

 small, the lateral long and straightish. 1 t 9 q..2^. — Ohio. 1 



U. Granosus. Brug. Journ. H. N. 1. t. 6. f. 3, 4. — Lam. 

 37. — E. t. 249. f. 2. Obovate, convex- depressed, reddish brown, 

 anteriorly broader and rounded ; with oblique granular strise, the 

 granules crowded : nacre bluish white. If. — Guiana. 



U. Tuberculatus. Barnes, in Sil. J. 6. t. 7. f. 8. — Eaton. 

 — Hildr. in Sil. J. 14. Ovate-oblong, thick and rugged, anteriorly 

 produced compressed attenuated and rounded at the tip, posteriorly 

 short rounded and obtuse ; beaks flat and lower than the ligament : 

 cuticle dark brown with longitudinally elongated tubercles, anterior 

 slope bordered by a ridge from whence proceed deep and irregular 

 nodulous undulations ; nacre white, cardinal teeth crenated, the 

 lateral long and striated. 2j- . . 4^. — _ZV. America. 



U. Nov^e Hollands. Gray. Z. P. 1834. Oblong-elon- 

 gated, slender, solid : posteriorly subcompressed, smooth rounded ; 

 anteriorly subventricose, produced, with large unequal tubercles 

 disposed in curved radiating rows : the disc silvery and spotted 

 with purple, the ventral margin posteriorly very thick : posterior 

 cardinal tooth small, little elevated, bituberculated ; anterior teeth 

 small and placed under the anterior edge of the cartilage : cuticle 

 thick and black. River Macquarrie, New Holland. 



U. Cylindricus. Say. in Enc. Am. Nich. Conch, t. A.f. 

 3. — Eaton. — Hildr. — U. Naviformis. Lam. — Reeve, t. 89. 

 Transversely oblong, straight, posteriorly very short and rounded, 

 ligamental edge very long and straight, ventral edge incurved in 

 the middle ; anteriorly angulated above and below and emarginate 

 at the tip : beaks not prominent and as well as the anterior slope 

 (which is bounded by a broad flattened umbonal ridge) undulated : 

 cuticle yellow speckled with angular black marks, nacre pearly 

 white, teeth crested. 1J..3 — Ohio. 



* * * Spinous. 



U. Spinosus. Lea. on U. 2. p. 57. t. 16. f. 50. — Jay. Cat. 

 ed. 3. pi. 5. Subtriangular, inflated, inequilateral, acutely angular 

 anteriorly, thickish, beaks scarcely prominent, cuticle dark brown 

 and shining, armed with a few long and thick spines : cardinal 

 teeth inclining downwards, the lateral rather large and curved : 

 nacre purple. If . . 3 T 3 jj. — Georgia in America. 



* * * * Smooth. f Triangular. 



U. Arcleformis. Lea. on U. 1. p. 126. t. 17. ./. 44. — 

 Nexus. Say. Am. C. t. 51. Subtriangular, very ventricose, 



Add likewise the U. Leeai of Gray. 



