378 MAZATLAN UNIVALVES 



442. Tbivia 8ANGUINEA, Gray. 



Deser. Cat. p. 14, no. 119.— JT. ^ A. Ad. Gen. i. 269. 



Cjprsea sanguinea, Soiv. Cat. Cypr. p. 12, no. 115 : — Conch. HI. 



pi. 6, no. 32. — Lam. An. s. Vert. vol. x. p. 570, 102. — Rve. 



Conch. Ic. pi. 23, f. \27.— Chen. Lee. Mem. pi. 10, f. 9, 10.— 



Mke. in Zeit. f. Mai. 1847, p. 183, no. 29:— 1851, p. 34, 



no. 114.— C. B. Ad. Pan. Shells, p. 38, no. 12. 

 + Cyprsea fusca, Gray in Sotv. Conch. Lll. no. 120, f. 37. — Bve. 



Canch. Lc. pi. 24. sp. lU.—Mke. in Zeit.f. Mai. 1851, p. 34. 



no. 115. (G-alapagos & Bay of Guayaquil, Cuming.) 

 Comp. Cypraoa rubescens,* Gray, Proc. Zool. Soc. 1832, 



p. 185.— i^t-e. Conch. Ic. pi. 25, sp. 141.— C. B. Ad. Pan. 



Shells, p. 38, no. 11. (Gralapago.s, Cuming. — Panama, C. B. 



Adams.) 



After very careful and repeated examinations of many 

 hundred specimens, I feel unable to separate the C. fusca from 

 the C. sanguinea. Tlie colour varies from very dark brownish 

 purple, with blood-red stain on the back, to a brown with 

 scarcely any admixture of purple or red ; and again to a general 

 reddish pink, like C. rubescens. The differences of shape, 

 from a rounded form approaching T. subrostrata to an elonga- 

 tion approaching T. suffusa, do not accompany the differ- 

 ences of colour, but are found in each state. The swelling at 

 the basal margins is very variable. The sculpture is by no 

 means constant, the ribs (of uncertain number) being continu- 

 ous over the back, or variously inlerrupted ; intercalations and 

 confluences frequejitly appearing. The columella is broadly 

 indented over the whole length, with a wave in the middle. 

 The smallest sp. measures long. "27, lat. "21, alt. '17. 



Tbe largest sp. „ , 



An elongated sp. „ , 



A broad sp. „ , 



Hab. — Panama and Mexico, Sowerby. — St. Elena, under 

 stones, Cuming. — Panama, one dead sp. C. B. Adams. — 

 Mazatlan ; abundant, (generally dead ;) L'pool Col. 

 Tablet 1796 contains 5 sp. dark brownish purple, red stain 



developed.— 1797, 4 do. red scarcely appearing.— 1798, 5 sp. 



dark brown, red stain slight.- 1799, 4 do. red evanescent.— 



• The specimens of T. fusca and T. rubescens in Mus. Cuming seem to be 

 utreme varieties of T. sau^juinea. Those in Mus. Uaskoin however appear dis- 

 tinct, especially of the form rubescens. 



