COS A Revision of the American Cichlidse. 



dd. Gill-rakers stiff, lanceolate, crenulate on inner margin. Perciform. 

 .Scales small. Spinous and soft dorsals of nearly equal extent, and 

 -separated by a notch. Anal spines three. Each jaw with a broad 



band of viiliform teeth. Dorsal and anal fins scaly 3. (Jicllla 



<cc. Gill-rakers short and few. 

 /. Vertical limb of preopercle entire. 



g. Scales of the lateral line much longer than the others. About two 

 transverse series of scales in the anterior part to each scale of the 

 lateral line. First series of teeth incisors, separated from the rest 



by a moderate space 4. Uaril 



■gg. Scales of the lateral line not larger than the others. 



h. A series of incisors, a band of viiliform teeth behind them. 



Anal with 8 spines 5. IVeetroplllS 



hh. Teeth all -conioal, the front series remote or not. 

 i. Premaxillary verj greatly protractile. 

 j. Anal spines three. 



k. Lateral line not overlapping. Snout equal to post- 

 orbital portion of head. Mouth oblique, preorbital 

 narrow (^ orbit). Nostrils nearer tip of snout than eye. 



6. Acaropsis 

 kk. Lateral line with the upper and lower limbs overlap- 

 ping. Snout much produced, more than twice the length 

 of postorbital portion of head. Preorbital very large, 

 nearly twice as wide as the eye. Nostrils much nearer 

 orbit than tip of snout. Mouth low, nearly horizontal. 

 Premaxillary an orbital diameter below the eye. Caudal 

 densely scaled. Maxillary reaching to nostrils. 



7. ftetroculiis 

 jj. Anal spines 6. Snout not greater than postorbital portion 

 of head. Preorbital narrow. Mouth oblique, premaxillary 

 on level of lower third of eye, more protractile than in the 

 other genera. Maxillary reaching to front margin of eye. 

 The origin of the ventral falls vertically below that of 



dorsal 8 Petenia 



a. Premaxillary comparatively little protractile. 

 /. Ventrals inserted behind origin of dorsal. 



m. Jaws subequal 9. AstronotllS 



n. Anal spines three. 



o. Soft portions of vertical fins densely scaled to near 

 the tip ; dividing line between fins and body indis- 

 tinct. About 6 of the anterior teeth of lower jaw 



enlarged canines (Astronotus) 



00. Soft portions of dorsal and anal naked or scaled on 

 base only. Caudal scaled at its basal half. Lower 



jaw without enlarged canines.. (jEquidens) 



nn. Anal spines more than three (Cichlasoma) 



