Dr. J. E. Gray on a new species of Dolphin. 157 



both above and below ; but the whorls, which are three, instead 

 of two and a half, do not increase quite so rapidly in size. Its 

 distinctive feature consists in having three spiral ribs or carinas 

 of a shining fulvous tint, which contrast strongly with the 

 whitish ground colour of the shell ; one is situated on either side 

 extending from the apex to the orifice, and the third, which is 

 not so distinctly elevated, on the centre of the body. 



The entire volutions appear under a good lens strongly 

 wrinkled longitudinally, more especially on the inner sides, and 

 under a still higher power finely striated spirally. The mouth, 

 which is well rounded and does not turn to either side, embraces 

 a considerable portion of the body-whorl. The operculum I 

 have not been able to examine : its diameter hardly equals the 

 twentieth of an inch. 



As yet I have only obtained four specimens, but have still 

 some small portion of the sand in which they were found, remain- 

 ing unexamined. 



If the shell as described above is already known, I should feel 

 greatly obliged if any of your scientific correspondents would 

 favour me with the name. 



I am borne out in my opinion that it is new to the British 

 fauna by Dr. Battersby of Torquay, who has kindly examined the 

 shell ; should it prove equally new to science, Skenea tricarinata 

 would be a very appropriate designation. 



It may be interesting to some of your readers to know, that I 

 met with several fine specimens of the rare Crenella costulata in 

 rock-pools in Mount's Bay, and also with Modiola phaseolina in 

 some abundance in the same locality. 



Yours faithfully, 



Upton Hall, near Birkenhead, W. Webster. 



June 21, 1856. 



EXPLANATION OF PLATE VIII. 



Fig. 12. The shell highly magnified. Fig. 13. Natural size. 



XVII. — Description of a New Species of Dolphin (Steno) from 

 the upper parts of the River Amazon^. By J. E. Gray, Ph.D., 

 F.R.S. &c. 



Mr. H. W.Bates has sent to the British Museum the skulls of 

 two Dolphins which he has procured from the upper parts of the 

 Amazon. 



The first is named Bouto by the natives, and found near 

 Ega. It is evidently the Delphinus Geoffroyii of Desmarest, 



[* A brief abstract of a notice of two species of Dolphins occurring in the 

 Amazon, by M. Paul Gervais, appeared in the Annals, vol. xvii. p. 521. — 

 Ed. Ann. Nat. Hist.'] 



