FISH. 63 



of the head and body, denticulated suborbital and preopercle, unarmed opercle, 

 four-rayed branchiostegous membrane, and in the size and mode of arrangement 

 of the scales on the body. I am not aware that any species of Pomacentrus have 

 the dorsal and anal fins so completely covered with scales : but, according to 

 Cuvier and Valenciennes, there is a species of Glyphisodon* to which genus 

 Pomacentrus is closely allied, which has these fins almost as entirely scaled, as 

 in the true Squamipinnati ; and if so, there is nothing but the palatine teeth which 

 of necessity demands the separation of this new genus from the Sciaznidaz. 

 These teeth can be distinctly felt upon the vomer, but I am not quite sure from the 

 small size of the fish, and its mouth also being small, whether they exist on the 

 palatines as well. It may be added that this genus shews further itself an affinity 

 to Glyphisodon, in the filamentous prolongation of the first soft ray in the ventrals. 

 This character is not, I believe, found in Pomacentrus. 



In which ever family it is placed, it forms a beautiful connecting link between 

 the two. It is from the Cape Verde Islands. 



Stegastes imbricatus. Jen. 



Plate IX. fig. 2. 



Form. — Oblong-oval ; the body much compressed. Greatest depth rather more than one-third of 

 the entire length : head one-fourth of the same. Snout short and obtuse ; the profile rising 

 very obliquely, and forming with the dorsal line one continuous curve. The back is sharp, and 

 appears more elevated than it ceally is, in consequence of the dorsal fin being thickly coated 

 with scales, and scarcely distinguishable from the body. Ventral line less convex than the 

 dorsal ; the edge of the abdomen somewhat carinated between the ventral and anal fins, but 

 in advance of the former rounded. The upper and under profile meet at the mouth at a right 

 angle. Mouth small, and scarcely at all protractile. Jaws equal ; each with a single row of 

 cutting teeth, which are small, though rather larger below than above, even and closely set, 

 forming a compact series : no secondary teeth behind : vomer rough with minute velutine teeth. 

 When the mouth is closed, no portion of the maxillary is concealed by the suborbital. Eyes 

 round, moderately large, their diameter rather less than one-third the length of the head, placed 

 high in the cheeks, and nearer the end of the snout than the posterior angle of the opercle, the 

 distance from the former being rather less than one diameter. The nostrils consist of a single 

 minute round aperture, about half-way between the eye and the anterior margin of the 

 suborbital. The suborbital has its margin entire as far as the end of the maxillary, at which 

 point it curves backwards and upwards to form a narrow band beneath the eye, and the lower 

 margin of this band is denticulated. The preopercle is likewise denticulated ; but the denticu- 

 lations, which are principally confined to the ascending margin, are not very obvious, and more 



* G. chrysurus, Cuv. et Val. 



