268 CHROMIDKS. 



the orbit, sliglitly convex. The naked portion of the pneoperculum 

 is as high as long, and at the angle as wide as the scaly part below 

 the eye. 



The dorsal spines vary considerably in number and in length ; 

 they are always very strong, broader on one side than on the other ; 

 the seventh and eighth rays form the highest part of the soft dorsal, 

 and extend sometimes to the middle of the caudal. Anal and ventral 

 spines very strong. Pectoral composed of fourteen rays, the fourth 

 and fifth of which extend to the anal ; the ventral extends to the 

 vent. Scales cycloid, higher than long; one of the largest covers 

 three-fourths of the orbit. 



The lower pharyngeals are united by a suture, triangular, and 

 armed with veiy small villiform teeth. 



Greenish-olive, shining silvery, each scale with darker centre ; 

 a dark spot on the operculum ; the soft portions of the vertical fins 

 with whitish spots, surrounded by oblique or transverse blackish 

 streaks. 



This species attains to a length of sixteen inches. 



Skeleton. — The bones of this species are very solid and firmly joined 

 to"'ether. The jaw-bones are short ; the processes of the intermax- 

 illaries are received into a very broad groove, not extending backwards 

 to the front margin of the orbit. The upper surface of the skull is 

 veiy broad, pro\'ided with strong longitudinal crests, of which that of 

 the occipital is the highest. Base of the skull with a pair of flat and 

 rather small condyles for the articulation of the upper pharyngeals. 

 Vertebral column composed of eighteen abdominal and foiu'teen caudal 

 vertebrae, the former portion being considerably the longer. The 

 thii-d vertebra has a very broad and strong process, extending down- 

 wards into the abdominal cavity. 



2. Chromis niossambicus. 



Chromis niossambicus, Peters, Berl. Monatsber. 1852, p. 681. 



niloticus, Peters, Wiegm. Arch. 1855, p. 267 ; 3IuUer, Monatsber. 



Berl. Acad. 1844, p. 32. ' 



D '±^. A. -. L. lat. 30. L. transv. 4/12. 



Teeth small, in several series ; thirty-five on each side of the front 

 series in the upper jaw. Scales below the eye in three series, the 

 upper extending to below the posterior margin of the orbit. Snout 

 obtusely conical, with the upper profile oblique. Caudal subtruncated ; 

 the soft dorsal extends to, or nearly to, the middle of the caudal, if 

 laid backwards. Greenish-olive, shining golden, each scale ^^'ith 

 darker centre ; vertical fins blackish, with more or less distinct 

 whitish spots. Young specimens with an ovate black spot behind 

 the base of the last dorsal spine. 



Fresh waters of Mozambique, 

 a-it. Zambeze. From Prof. Pcters's Collection. 

 /. ni. Mauritius : stuffed. From Sir A. Smith's Collection. 



Although this species is closely allied to Ch. niloticus, we cannot 



