THE ANNALS 



AND 



MAGAZINE OF NATUEAL HISTOFtY. 



[SEVENTH SERIES.] 

 No. 88. APHIL 1905. 



XLIT. — A Revision of the Fishes of the South- American Cichlid 

 Genera Acara, Nannacara, Acaropsis^ and Astrouotus. 

 By C. Tate Regan, B.A. 



The Cichlidee have recently been monographed by Pellegrin 

 (Mem. Soc. Zooh France, xvi. 1904), who has dealt in a 

 most interesting manner and at considerable length with 

 their anatomy and with the biological problems which they 

 present. However, I have arrived at somewhat different 

 conclusions as to the distinction and arrangement of species 

 in certain genera, which must be my excuse for the present 

 paper. 



The genera here dealt with are distinguished from other 

 American Cichlidae by the following combination of cha- 

 racters : — Dorsal fin without notch between spinous and soft 

 portions ; gill-rakers short, in small or moderate number ; 

 anal hn with 3 spines ; teeth conical; prseoperculum entire; 

 no lobe on the anterior branchial arch. Their relations to 

 each other may be shown thus : — 



I. Soft vertical fins scaleless or scaly at the base onlv. D. XIII-XVI 



7-12; A. Ill G-11. 



A. Maxillary not exposed ; pra2maxillaries moderately protractile. 



Upper lateral line well separated froni dorsiil fin Acarci. 



Upper lateral line separated from dorsal fin by only \ a 



series of scales for most of its leng;th Xannacara. 



B. Maxillary exposed ; prseniaxillaries very protractile. Acaropsis. 



II. Soft vertical fins covered with small scales; D. XII-XIV 19-21; 



A. Ill 15-16 Astronotus. 



Ann. & Mag. N. Hist. Ser. 7. Vol. xv. 23 



