2. cnROMis. 209 



agree with Prof. Peters, who considers both as identical : there are 

 three very distinct series of scales un the cheek, and one series less 

 above the lateral line ; the teeth are equal in number in both species, 

 but conspicuously larger in that from the coast of Mozambique ; the 

 cleft of the mouth is wider. 



3. Chromis spamnamii. 



Tilapia sparrniauni, Smith, III. Zool. S. Afi: Pise. pi. 6 (not good), 

 l^-^'- ^-^-^o- r..lat.28. L.transv.i-, 



Teeth small, in several scries ; scales below the eye in two series ; 

 snout very obtuse and short; caudal subtruncated ; the soft dorsal 

 extends nearly to the middle of the caudal, if laid backwards. An 

 ovate black spot at the base of the anterior soft dorsal rays. 



Freshwater streams to the north of Orange River. 



a-h. Five inches long: stuffed. From Sir A. Smith's Collection. — 



Types of the species. 

 c, d. Fine specimens. From Sir A. Smith's Collection. 



Description. — This species is very different from Ch. niloticus and 

 Ch. mossambicus, with which it has been confounded, and may be 

 readily distinguished by its larger teeth and low cheeks. The height 

 of the body is contained twice and a half in the total length (without 

 caudal), the length of the head thrice and a third. Tho upper profile 

 of the head is slightly convex. Snout obtuse, short, not longer than 

 the eye ; cleft of the mouth as long as broad. Teeth small, in three 

 series ; there are twenty-two on each side of the front series of the 

 upper jaw. Interorbital space as broad as the orbit, rather flat. The 

 naked portion of the praeoperculum is higher than long, and at the 

 angle narrower than the scaly part below the eye. 



The first ventral ray is produced into a filament, which sometimes 

 extends to the middle of the anal. 



Greenish-olive, shining silvery, with indistinct darker transverse 

 bands ; a dark spot on the operculum ; the soft portions of the ver- 

 tical fins with transverse series of dark spots ; an ovate black spot on 

 the base of the last spine and of the three first rays of the dorsal fin. 



4. Chromis tristrami. 

 Haligenes tristrami, Gunth. Proc. Zool. Soc. 1859, p. 471. pi. 9. fig. B. 

 -p i4_M7) ^1 L. lat. 28. L. transv, 3/11. 



Teeth rather small, twenty-three on each side of the outer series 

 of the upper jaw ; scales below the eye in three series ; snout obtuse 

 and rather elevated ; the height of the body is two-fifths of the total 

 length (without caudal) ; the lower profile scarcely curved ; the soft 

 dorsal extends to, or beyond, the middle of the caudal, if laid back- 

 wards. Greenish, with seven or eight dark vertical bars ; a dark 



