ICHTHYOLOGY. 557 



is unnamed, is black above and of a lighter colour beneath. D. 14, 14; 

 A. 3, U. 15". 



Gerres equula, id. (ib.) 1). 9, 11 ; A. 3, 8. Greenish blue. 



Ditrema, n. g. id. (ib.), in the family of the Maeuides, is distinguished by 

 a very low dorsal fin and an opening behind the anus. The spscies has D. 

 10, 22 ; A. 3. 27. 



He has instituted a new genus Cheetopteriis, wliich, in habit, would appear 

 very nearly to approach Aphareus ; but it is furnished with voraeral teeth 

 and four rays in the branchiostegous membrane. D. 10, 10; A. 3, 8. 



In the family of the Squamipennes several new genera 

 and species have been instituted. 



Cheetodon wmlr*/ />.-;, Schlegel (Fauna Japonica, p. 80.) resembles Ch. 

 melanopus, Reiuwardt ; it is milk-white, with four light brown bauds, a black 

 spot on the commencement of the soft part of the dorsal fin. D. 11, 21 ; 

 A. 3, 20. Ch. aureus, id. Brownish yellow, a black perpendicular stripe 

 across the eyes, and twenty dark longitudinal bands on the sides. 



Holacanthus septentrionalis, id., allied to (tnnularis ; but the dorsal and 

 abdominal fins are not prolonged into points ; about twelve blue longitudinal 

 stripes. D. 13, IS ; A. 3, 18. 



A new genus, Hypsinotus, has been instituted by the same naturalist, after 

 a figure by Burger. It is characterized by the position of the ventral fins 

 close to the anus, by the lowness of the soft dorsal fin ; the body is nearly as 

 high as it is long. The fish is brick-red. B. 6 ; D. 8, 27 ; A.*3, 26. The 

 genus is placed near Drepane. 



Another new genus, Histiopterus, by the same author, is placed near 

 Tawrichthys and Heniochus, which it resembles in the figure of the body. 

 The dorsal fin is very high, and presents four strong spines ; head covered 

 with asperities, teeth setiform, no scales on the fins. It includes two spe- 

 cies : H typus, D. 4, 27 ; A. 3, 11. The third ray of the dorsal fin the 

 longest. H. acutirostris, the snout shorter, and the fourth ray the 

 longest. 



Valenciennes has described, in the Ichthyologie des Canaries, a fish, 

 approaching the genus Brama, as a new genus, Neobrama Webbii. The 

 same fish had been already named by Lowe Polymixia nobilis, which name 

 has the priority. Valenciennes gives the following characters .- Corpus 

 oblongum, squamis asperrimis tectum ; caput parvum, squamosum, rostrum 

 ac rnandibula superior nuda ; maxilla inferior squamosa, infra cirris duobus 

 lougis symphysi affixis instructa ; deutes in maxillis, in palato, in vomere ac 

 in lingua miuuti, creberrimi, velutiui ; ossa opercularia iuermia, squamosa, 

 prseter interoperculum nudum, cutaceum ; pinnae dorsales coadnatse, ventrales 

 radiis ramosis septem ; membrana brauchiostega racliis quatuor. 



