NATURAL SCIENCES OF PHILADELPHIA. 113 



membrane behind each of which is deeply and acutely notched. Ventral gene- 

 rally obtuse or rounded. Caudal fin truncated or subtruncated. 



Chironemus appears to be entitled to take rank as the type of a distinct group 

 of Cirrhitoids, its physiognomy being quite different from that of any other 

 division 5 the characters above, given are sufficient to distinguish it, and they 

 will doubtless be found to be accompanied by others of more importance when 

 the family shall have been fully investigated. 



Chironemus Cuv. et Val. 



Synonymy. 



Chironemus Cuv. et Vol., Histoire Naturelie des Poissons, vol. iii., p. 78. 

 Threpterius Richardson, Proc. Zoological Society of London, 1850, p. 68 ; ib. 



in Annals and Magazine of Natural History, vol. vii., p. 284, 1851. 

 Chironemus Giinther, Catalogue of the Acanthopterygian Fishes, &c, vol. ii., 

 p. 76. 



Body oblong, highest above or before the ventral fins. Scales rather large. 

 Head moderate, subcorneal and longer than high. Occipito-nasal profile nearly 

 straight; snout scarcely convex. Crown, forehead and cheeks naked. Oper- 

 culum, suboperculum and interoperculum scaly. Preoperculum entire, nearly 

 vertical or slightly oblique behind and rounded at its angle; operculum with 

 two spines. Eyes anterior. Suborbital bones narrow. Anterior nostrils with 

 a membranous appendage. Mouth oblique, moderate. Supramaxillary bones 

 ending near the vertical of the anterior borders of the orbits. Teeth generally 

 villiform, in a band on each jaw and on the front of the vomer. Branchios- 

 tegal rays 6, 6. Dorsal fin commencing above or little before the bases of the 

 pectorals, with its spinous portion longer than the soft, convex and with four- 

 teen or fifteen spines, the penultimate of which is lower than the soft portion ; 

 its membrane is deeply notched behind each spine. Anal fin short, with three 

 spines and six or seven branched rays. Caudal fin entire or convex. Pectoral 

 fins with its inferior simple rays produced, and the intervening membrane 

 deeply no'ched. 



Type. Chironemus georgianus Cuv. et Val. 



With Dr. Giinther, we have, for the present, retained the Threpterius maculo- 

 sus of Sir John Richardson and the Chironemus marmoratus of the former 

 gentleman in this genus to which both have been referred. It is quite probable, 

 however, that the genus may be hereafter found not to be homogenous, and 

 that Threpterius may be re-established, but with quite different characters from 

 those assigned to it by its founder, who named it from a misconception of its 

 true relations, and did not perceive its affinity to the Cuvieran Chironemi. 



The principal distinctive characters of the three species combined under this 

 generic designation are as follows : 



Second simple pectoral ray produced to the anal ; soft dorsal 



half as long as spinous C. georgianus. 



None of the pectoral rays much produced beyond others. 



Teeth of jaws nearly uniserial : soft dorsal two thirds 



as long as spinous C. maculosus. 



Teeth of jaws villiform, in a broad band ; soft dorsal 



rather shorter than spinous C. marmoratus. 



Not having been able to examine any of the species of the genus, we are not 

 prepared to state what may be the value of those characters, or whether they 

 are entitled to be regarded as more than specific. The type of the genus is 

 very imperfectly known, having been only described by Cuvier and Valenci- 

 ennes from a much injured specimen. 



The three species are confined to the Australian seas. 



1862.] 8 



