Cope.] J-^^ [Jan. 5, 



posteriorly. The latter character reduces the number of scales of the 

 lateral line and alters the relative proportions generally. Thus the length 

 of the caudal peduncle equals that of the preorbilal bone to the orbit ; in 

 the O. (jymnogenys it equals the length of that bone plus the diameter of 

 the orbit. The coloration of the fins is also peculiar. 



Geophagus brasiliensis Quoy and Gaimard ; Steindachner, Sitzb. K. 

 Wien Akad., 1871, December, p. 13. 



Anterior border of orbit considerably farther from the end of the muz- 

 zle than the posterior border is from the convex edge of the operculum. 

 The middle of the length of the head falls near the middle of the pupil. 

 Profile straight and steeply descending. Preorbital bone 1.75 times as 

 long as the diameter of the orbit. Cheeks with five rows of scales. 



Form of body oval, a little higher in front. Scales 28. Fin radii, D. 



~8~ 



XV". 11 ; A. III. 9. Greatest depth two and one-third times in length to 

 base of caudal fin ; length of head in same two and three-quarter times. 

 Diameter of eye entering head 4.66 times, and twice in the interorbital 

 width, measured over its strong convexity. Caudal fin rounded, trun- 

 cate in tlie middle, its basal portion scaly throughout. 



Color light brown in alcohol, each scale with a paler centre ; a large 

 black spot below the lateral line opposite the middle of the spinous dor- 

 sal fin. A few scattered pearl Itlue spots on the operculum and on the 

 scales posterior to it. Caudal fin, spinous dorsal,, and base of soft dorsal 

 dusky ; the caudal with oval transparent spots and the spinous dorsal 

 with a few oblique transparent streaks, directed upwards posteriorly. A 

 few round transparent spots at the posterior base of the soft dorsal. 

 Faired fins unspotted, the anterior rays of the ventrals dusky. 



Total length, 193 mm.; length to base of caudal fin, 153 mm.; length 

 to base of anal, 102 mm.; length to base of ventrals, 58 mm.; length of 

 head, 54 mm. 



This species agrees with the O. gymnogenys and camurus in its scale for- 

 mula, and with the G. brachyurus in its scaly cheek and coloration. It 

 diflFers from all of them in the more posterior position of the eye and 

 length of preorbital bone, and in the shape of the caudal fin. In some 

 respects it agrees with the Geophagus macrolepis of Gunther,* but in that 

 fish the eye has a much more posterior position. There is but one speci- 

 men of the G. brattiiiensis in the collection. 



AcARA TETUAMERA Heckel BvasU. FluiS-Fuclie ; Ann. derWien Mas , ii, 

 p. 341. Steindachner Sitzber. Wien Akad., 1875, January, p. 5. 



Numerous specimens. Dr. Steindachner having endeavored to show 

 that the A. flavilabris Cope, is identical with this species, I embrace the 

 present opportunity of making a direct comparison. With five speci- 



• Calal. Fishes Brit. Mus., iv, p. 314. 



