286 Zoological Society: — 



developed in very young fishes, such as Dicrotus armatus probably 

 was ; and teeth are apt to disappear from the vomer when fishes ac- 

 quire their full growth. It may be mentioned in confirmation of 

 this view, that I obtained a scaleless fish, not quite six inches in length, 

 which had its ventrals reduced to single spines, had teeth on both 

 palatines and the vomer, and had the last four or five rays of the 

 second dorsal fin distant from, and unconnected by membrane with, 

 the rest of the fin ; whilst the last two or three rays of the anal fin 

 were separated from the anterior portion. This was therefore a Di- 

 crotus with imperfectly formed finlets, showing a closer approach to 

 a fully developed Prometheus atlanticus than D. armatus. 



After attentively considering the descriptions of the species placed 

 by Dr. Giinther under the genus Thyrsites (Brit. Mus. Cat. ii. 350), 

 as well as some of the fishes themselves, it appears to me that a more 

 satisfactory arrangement would be to distribute the species amongst 

 three genera, thus : — 



1. Thyrsites. Fishes having teeth on the palatines, perfect 

 ventrals, finlets, and a skin naked or furnished with simple scales. 



T. Atun, C. & v., and T. lepidopoides, C. & V. 



2. RuvETTUs. Includes a single very distinct species, remark- 

 able for having a keeled abdomen, and the skin everywhere furnished 

 with bony bodies, each bearing several spines — possessing also teeth 

 on the palatines, perfect ventrals, and finlets. 



R. pretiosus, Cocco. 



3. Prometheus. Distinguished by having each ventral reduced 

 to a single spine, as well as by having teeth on the palatines, finlets, 

 and a skin either naked or furnished with simple scales. 



P. atlanticus, Lowe ; P. Solandri, C. & V. ; P. prometheoides, 

 Bleek. 



The genus Gempylus is distinguished from all these by the absence 

 of teeth from the palatines. 



To return for a moment to Ruvettus pretiosus (" ce curieux, ce 

 precieux poisson," — Valenciennes), the "Escolar" of Madeiran 

 fishermen, it may be noted that, although one of the characters given 

 in the ' British Museum Catalogue ' is the want of a lateral line, this 

 line may be made out in fishes fresh from the sea. It commences 

 on a level with the upper border of the opercle, but at some distance 

 behind it, and then descends gently until it arrives at the middle of 

 the height of the fish, which position it keeps on the posterior half 

 of the body. 



May 23, 1865.— John Gould, Esq., F.R.S., in the Chair. 



Notice of a New Species of Australian Sperm Whale 

 (Catodon Krefftii) in the Sydney Museum. By John 

 Edward Gray, Ph.D., F.R.S., V.P.Z.S., F.L.S., etc. 



In a letter which I lately received from Mr. Gerrard KrefFt, the 

 intelligent Secretary and Curator of the Australian Museum, he sent 

 me some photographs (taken like those formerly sent by Mr. Henry 



