16 Mr. R. B. Hinds's Descriptions of new Shells. 



2. Ryania Ccmdollci, Vahl, Patrisia bicolor, DeC. Prod. i. p. 25; 



3. R. Patrisii, Vahl, Pntrisia parvifiora, DeC. I.e. 



4. R. dentata, Vahl, Patrisia dentata, H. B. K. 



5. R. Kunthii, Vahl, Patrisia affinis, H. B. K. 



Roterodanii, m. Novemb. 1S42. 



V. — Descriptions of new Shells from the Collection q/" Captain 

 Belcher, R.N., C.B., ^c. By Richard Brinsley Hixds, 

 Esq., Surgeon R.N. 



The genus Triphoris^ was established by M. Deshayes in 1824 

 to receive a small fossil reversed shell, having a near affinity 

 to Cerithium, and which was characterized as the type of a 

 group, as an elongated shell, turrited, inflated about the mid- 

 dle, sinistral, terminated by three rounded openings, the an- 

 terior being the largest, another at the base tubular, and a 

 third posterior. Some recent shells were, however, soon con- 

 veniently placed in the same group, as the Cerithium perversnm 

 of Lamarck, and the old Murex adversus of our own coasts. 

 The number of recent species amounts to five in Kiener's re- 

 sume of Cerithium, where they constitute his fourth group. I 

 have found the species so numerous in the collection of Capt. 

 Belcher, C.B., that they give a very formidable appearance to 

 the genus, which seems likely to become extensive. This 

 accession also makes it necessary to alter the character of the 

 genus to some extent. Though all the species have diminu- 

 tive shells, and generally require the assistance of a glass for 

 their examination, yet they will be found to possess very di- 

 stinct characters, and are at the same time eminently beautiful 

 in their form and sculpture. If we except some fluctuation 

 in colour, which may probably be attributable to locality, they 

 seem liable to little variation. The only circumstance neces- 

 sary to guard against in the discrimination of species, accord- 

 ing to my own experience, is the circumstance, that in the 

 transverse series of granulations which prevail in many, the 

 number will be found to fluctuate with age. Thus, in the 

 Mediterranean shell, Triphoris pei'versus, the young will be 

 found to possess only two series of granules ; when more ad- 

 vanced in age, a third, intermediate in position, and smaller, 

 is added ; and in the full-grown shell the last whorl has four 

 distinct series. Whilst the shells from Captain Belcher's col- 

 lection were under examination, Mr. J. E. Gray and Mr. W. 

 Metcalfe did me the favour to place their specimens at my 

 disposal, which has enabled me to add several more species. 



* Triphoriix of Swainson's Treatise, and Triphora of Sowerby's Manual. 



