1862.] DR. A. GXiNTHER ON NEW REPTILES AND FISHES. 191 



the diameter of which is scarcely more than one-third of the length 

 of the head. Cleft of the mouth slightly oblique, of moderate width, 

 the maxillary extending beyond the front margin of the orbit ; jaws 

 equal in length anteriorly. Each turbinal bone with an obtuse spine 

 superiorly; prseorbital spine strong ; prseoperculum with five spines, 

 the upper of which is the longest ; operculum with two ridges ; 

 spines on the occiput small and obtuse. Head naked, without cu- 

 taneous appendages ; vomerine teeth in a narrow angular band. 



The dorsal fin commences immediately behind the occiput, its 

 spines are of moderate length and strength ; the third to the sixth 

 are the longest, half as long as the head ; the following decrease in 

 length, the last, again, being a little longer than the penultimate ; the 

 soft dorsal rather more elevated than the spinous, short, the length 

 of its base being contained thrice and a fifth in that of the spinous 

 dorsal. Caudal fin scaleless, rounded, contained four times and two- 

 thirds in the total length. The anal commences opposite the four- 

 teenth dorsal spine ; its second spine is the longest, contained twice 

 and two-thirds in the length of the head. The pectoral has the rays 

 branched, and extends nearly as far backwards as the ventral, which 

 is composed of a strong spine and five soft rays ; the region round 

 the base of the pectoral and ventral fins is naked, covered with soft 

 skin. 



The gill-membranes are scarcely united below the throat. There 

 is a distinct cleft behind the fourth gill*. 



Length of the specimen, 3 inches. 



Catopra siamensis. (PI. XXVI. fig. A.) 

 D. ^. A. ^. L. lat. 27. L. transv. fj. 



The height of the body is contained twice and a third in the total 

 length. Cheek with six series of scales, the lower of which covers 

 the prseopercular limb. Body with eight dark cross bands ; scales 

 on the nape with some minute whitish dots ; the outer edge of the 

 ventral white. 



Siam. 



Description. — The height of the body is contained twice and a 

 third in the total length, the length of the head thrice and a third ; 

 head as high as long. Snout rather shorter than the eye, the dia- 

 meter of which is one-fourth of the length of the head, and equal to 

 the width of the interorbital space. The lower jaw is scarcely longer 

 than the upper, and the maxillary extends slightly beyond the ante- 

 rior margin of the orbit. Two nostrils remote from each other, both 

 very small. Prseorbital and angle of the prseoperculum slightly ser- 

 rated ; opercles, throat, and isthmus entirely scaly. The dorsal fin 

 commences above the end of the operculum, and terminates close by 

 the caudal ; its spines are very strong, and can be received in a 



* I have been induced by that circumstance to re-examine C. australis, and 

 have found a very small opening behind the fourth gill ; so that the presence of 

 such a narrow cleft is to be introduced into the diagnosis of the genus Centro- 

 pogon (Catal. Fish. ii. p. 128). 



