16 ACANTHOPTERYGII. 
Synopsis of the Cichlid Genera represented in Mexico and Central America. 
I. Anal fin with 8 spines. 
No lobe on the anterior branchial arch. . . 2. . . - 1. Acara. 
A compressed lobe on the upper part of the anterior branchial arch - 2. GropHacus. 
II. Anal fin with more than 8 spines. 
Teeth all conical or cylindrical; mouth small or moderate, moderately 
protractile, the preemaxillary spines (ascending processes) shorter 
than the head. . 2. . 2. ww 1 we eee ee 8 CrcHLosoma. 
Teeth all conical or cylindrical; mouth large, very protractile, the 
preemaxillary spines as long as the head . . . . ee - 4, PETENIA, 
Several series of small conical teeth and an outer series of larger teeth, 
all or most of which are compressed, incisor-like . . . . . . 5. Hertcutuys. 
Teeth all compressed, entire, with pointed or rounded apices. . . . 6. PARANEETROPLUS. 
Teeth all compressed, entire, with truncate apices . . . . . 7. NEETROPLUS. 
Teeth all compressed, mostly tricuspid, only the median ones of ‘the 
outer series being entire, with truncate apices . . . . . . . 8. Herorrapia. 
1. ACARA, Heck., 1840. 
Acara, Regan, Ann. Mag. Nat. Hist. (7) xv. 1905, p. 330. 
This, the most generalized genus of American Cichlids, is very closely allied to the 
African Paratilapia, which it resembles not only in external features, but also in 
the anatomy. The only difference between them is that the maxillary is completely 
hidden by the preorbital in Acara, whilst it is more or less exposed distally in 
Paratilapia. Of the nineteen species of Acara, only one is found as far north as thie 
Isthmus of Panama. 
1. Acara ceruleopunctata, Kner & Steind., 1863. 
Acara ceruleopunctata, Regan, Ann. Mag. Nat. Hist. (7) xv. 1905, p. 386. 
D, XIV-XV 10-11. A. III 8-9. Se. 26-28 ~. Preoperculum scaleless ; dorsal and anal fins scaleless ; 
depth of body 2 to 23 in the length; 6 gill-rakers on the lower part of anterior arch; dorsal spines 
increasing in length to the last, which is nearly 4 the length of head. 
Hab. Panama, Rio Chagres.—N.W. Ecuapor. 
2. GEOPHAGUS, Heck., 1840. 
Geophagus, Regan, Ann. Mag. Nat. Hist. (7) xvii. 1906, p. 50. 
Closely allied to Acara, differing only in the structure of the anterior branchial arch. Of the twelve species 
eleven are South American. 
1. Geophagus crassilabris, Steind., 1877. 
Geophagus crassilabris, Regau, Ann. Mag. Nat. Hist. (7) xvii. 1906, p. 58. 
D. XVI 10-11. <A. III 7-8. Se. 30-31 oe. 14 or 15 gill-rakers on the lower part of anterior arch ; 
pectoral $3 the length of head, not extending to above the anal. 
Hab. PANAMA. 
