256 Quarterly Joiimal of Conchologv. 



direction of Dr. Jeffreys during the cruise of the "Valorous." As 

 the result of these dredgings, 46 species, new to science, were dis- 

 covered and are here described by Dr. Jeffreys. 



In addition to the three genera previously noted at p. 224, a 

 genus is established for the reception of a species of Mytilida, viz. : 

 Idas, Jeffreys. 



Resembles Area in shape, the hinge plate crenated on both 

 sides the beak, cartilage none. 



The revolution in our ideas caused by the prolific results of the 

 recent examinations of the deep sea, in Avhich Dr. Jeffreys has 

 taken so prominent and honorable a part, has shown that the 

 greatest depths teem with a numerous fauna, and that the abysses 

 of the ocean retain in a living state many species of mollusca 

 hitherto supposed to be extinct and previously known only by their 

 fossil remains. 



A very full and carefully compiled synonymy is given of the spe- 

 cies enumerated, and the different depths and localities at which 

 the various species have been obtained in the present as well as 

 former expeditions are all furnished. 



The whole series contain a weahh of information on the deep sea 

 mollusca, and is one of the most important contributions to science 

 that has appeared for some time. 



The following is a list of the new species, omitting those pre- 

 viously mentioned at p. 224. 



Seguenzia formosa, Seguenzia carinata, Cerithium procerum, Lima- 

 cina helicoides, Terebratula tenera, Amussium lucidum, Lima 

 subovata, Idas argenteus, Leda pustulosa, L. lata, L. sericea, 

 Limopsis tenella, L. cristata, Diplodonta Torelli, Poromya rotun- 

 data, Pecchiolia gibbosa, P. tornata, Nexra striata, N. exigua, 

 N. notabilis, N. circinata, N. papyria, N. angularis, Dentalium 

 capillosum, D. ensiculus, D. subterfissum, Cadulus tumidosus, 

 C. gracilis, C. cylindratu>, Puncturella profundi, Scissurella 

 tenuis, Cyclostrema basistriatum, Acirsa pnxlonga. 



