2. PROTOTROCTES. 383 



conical snout, with the upper jaw longest ; the snout is rather longer 

 than the diameter of the eye, whicli is one-fourth of the length of 

 the head, and equal to the -width of the convex interorbital space. 

 The cleft of the month extends to below the anterior margin of the 

 orbit ; the intermaxillary and maxillary are very soUd bones, firmly 

 adherent to each other, and extending equallj* far backwards. The 

 intermaxillary alone is toothed, the minute teeth forming a single 

 series ; a similar series of teeth runs across the vomer and along each 

 palatine bone. The cheek and the opercular apparatus are naked. 

 Operculum quadrangular, as long as deep ; suboperculum well deve- 

 loped ; interoperculum hidden beneath the pra^operculiun. Bran- 

 chiostegals rather broad and short. The origin of the dorsal fin is 

 exactly midway between the end of the snout and the end of the 

 caudal, and its base corresponds to the middle of the interspace be- 

 tween the anal and ventrals ; it is rather higher than long. Anal 

 considerably longer than high. Caudal emarginate, with the lobes 

 equal in length, somewhat shorter than the head. The pectorals are 

 rather longer than the ventrals, two-thirds of the length of the head. 

 The scales are of moderate size, but rather irregularly arranged, thin, 

 and cycloid ; there is no lateral hue. Back greenish oKve ; sides 

 and bell}' silvery. 

 Southern Australia. 



a. Ten and a half inches long. From the International Exhibition, 

 1862. 



