15. MESOPS. 311 



lip is not interrupted in the middle ; maxillary not extending to the 

 vertical from the anterior margin of the eye. The scales on the cheek 

 are much smaller than those of the body, rather irregularly arranged 

 in five series. 



Spines of the fins very stout, gradually increasing in length pos- 

 teriorly ; the soft parts of the vertical fins produced. Pectoral longer 

 than the head, extending to the middle of the anal ; the outer ventral 

 ray, which is produced into a filament, reaches as far backwards as 

 the pectoral. 



YelloAvish-olive, shining golden, with a large black blotch on the 

 middle of the sides ; snout with two parallel bluish streaks : one 

 across the praeorbital, the other along the lower margin of the proo- 

 orbital and the orbit. Vertical fins with blackish streaks. 



I would observe, from notes made at Berlin several years ago, that a 

 specimen in the Collection of the Anatomical Museum, 1^ feet long, 

 also brought by Schomburgk from Guiana, and named Ch.JIavcscens, 

 belongs to this species. The following notes are from a skeleton in 

 the same Collection : — 



Crown of the heiid with a high crest, commencing on the frontal 

 bones ; its formation by two lamella) is very conspicuous anteriorly 

 where the long processes of tlie intcrmaxillaries are received between 

 them. There arc several foramina of the muciferous channels on the 

 procfrontals where they join the principal frontals ; the largest of 

 these channels is continued into the tubiform turbinal. The frontal 

 projects vciy strongly above the orbit, forming a convex roof. There 

 are two other ridges on the side of the occipital crest. The pra)orbital 

 large ; four other infraorbitals form an equally feeble and narrow 

 orbital ring. The dontary has posteriorly a long and broad process 

 which is nearljf rectangular to the articulary ; the latter with a pro- 

 cess directed forwards i)osteriorly : these two processes are remote 

 from each other, but united by a ligament. Os basilare with a broad, 

 sharp, lameUiform ridge. — Thirteen abdominal and as many caudal 

 vertebra) ; ten ribs. 



15. MESOPS. 



Geophagus, sp., Heckel. 



Body compressed, oblong, covered with scales of moderate or rathei- 

 large size ; eye in, or in advance of, the middle of the length of the 

 head ; praiorbital not elevated. Doi'sal spines numerous, anal spines 

 three ; base of the soft dorsal naked. Structure of the branchial 

 arches as in Oeophagus. Cleft of the mouth small ; teeth in a band, 

 small. 



Brazil. 



1. Mesops cupido. 

 Geophagus cupido, Heckel, BrusU. Fluss-Fische, p. 399. 

 D.iJ. A.f L.lat.32. 

 Fold of the lower lip continuous in the middle. Cleft of the mouth 



