16 ACAJS^THOPTERTGII. 



Sfjiwjjsis of the Cichlid Genera represented in Mexico and Central America. 



I. Aual fin with 3 spines. 



No lobe on the anterior branchial arch ] . Acara. 



A compressed lobe on the npper part of the anterior branchial arch . 2. Geophagus. 



II. Anal fin with more than 3 spines. 



Teeth all conical or cylindrical ; mouth small or moderate, moderately 

 protractile, the pmemaxillary spines (ascending processes) shorter 

 than the head 3. Cichloso.ua. 



Teeth all conical or cylindrical ; month large, very protractile, the 



prcemaxillary spines as long as the head J?. Petenia. 



Several series of small conical teeth and an outer series of larger teeth, 



all or most of which are compressed, incisor-like 5. Herichthys. 



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, onh^ the median ones of the 



outer series being entire, with truncate apices 8. Herotilapia. 



1. ACARA, Heck., 1840. 

 Acara, Picgan, Ann. jMng. Nat. Hist. (7) xv. 1905, p. 330. 



This, the most generalized genus of American Cichlidse, is very closely allied to the 

 African l^tratilajna, 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 prajorbital in Acara, whilst it is more or less exposed distally in 

 Paraiilnpia. Of the nineteen species of Acara, only one is found as far north as tlie 

 Isthmus of Panama. 



1. Acara cceruleopunctata, Kner & Steind., 1863. 



Acara Cn-rnlenimnctata, Ttcgan, Ann. J\Iag. Nat. Hist. (7) xv. 1905, p. 33G. 



D. XIV-XV 10-11. A. Ill 8-i). Sc. l(;-2S — . rricoperculum scalcless ; dorsal and anal fins scalclcss ; 



dopth of bodj' 2 to 2tJ in the length ; ii gill-rakers on the lower part of anterior arch ; dorsal spines 

 increasing in length to the last, which is nearly h tlie length of head. 



Halt. Panama, Eio Chagres. — N.W. Ecuador. 



2. GEOPIIAGUS, Heck., 1840. 



Geopl:a(ju!<, Regan, Ann. Mag. Nat. Hist. (7) xvii. 1906, p. 50. 



Closely allied to Acara, differing only in the structure of the anterior hranehial arch, ("if the twelve siiecies 

 eleven are Soutli American. 



1. Geopliagus crassilateis, Steind., 1877. 



Geojilidjjus cra.\s//ii6ri.s, liX'gan, vVnn. Mag. Nat. Hist. (7) xvii. 190(i, p. 5<S. 



1). XVI 10-11. A. Ill 7-8. So. 30-31 ,^'j|. 14 or 15 gdl-rakers on the lower part of anterior arch; 

 pectoral 'r^-:^ the Icnglh of head, not extending to ahofc the aual. 



JIub. PA.VAilA. 



