330 Mr. C. T. Regan on the Fishes of the 



I have given a list of the specimens in the British ^rusenni 

 on -which my descriptions are based^ with the total length of 

 each in millimetres. 



ACARA. 



Acara (part.), Heck. Ann. Mus. Wien, ii. 1840, p. 338; Giinth. Cat. 



Fish. iv. p. 276 (1862) ; Steind. Sitzb. Ak. Wien, Ixxi. 1875, p. 63. 

 j^quidens*, Eigenm. k Brav, Ann. Ac. N. York, vii. 1894, p. 616. 

 Acara, Pellegr. M<5m. Soc. Zool. France, xvi. l'J03, p. 171 (1004). 



Body deep or moderately elongate, compressed ; scales 

 large, usually finely ctenoid. Two lateral lines, the upper 

 well separated from the spinous dorsal. jNIouth small or 

 moderate; prsemaxillarics moderately protractile; maxillary 

 not exposed distally ; jaws with small conical teeth in bands, 

 those of the outer series more or less enlarged ; upper surface 

 of head scaly to between the orbits ; cheeks and opercular 

 bones scaly ; praeoperculum entire. Gill-rakers few and 

 short; no lobe on the upper part of the anterior branchial 

 arch. A single dorsal, with XIII-XVI 7-12 rays ; anal 

 with III 6-11 rays; soft dorsal and anal scaleless or scaly at 

 the base; caudal truncate or rounded. Pectoral asym- 

 metrical, with 12-15 rays; veutrals below or a little behind 

 the base of the pectoral. 



Eighteen species from S. America, extending into Panama. 



Skeleton. 



In A. tetrameriis the supraoccipital crest is high and 

 extends forwards on the frontals, which are hollowed out 

 anteriorly to form the posterior margin of the depression in 

 which the prsemaxillary processes lie. The latter are rather 

 short, extending nearly to above the orbit ; the parietal crests 

 are moderately strong and extend to above the middle of the 

 orbits. There are 26 vertebrae (13 + 13); parapophyses are 

 developed on the prrecaudal vertebrae from the fourth ; the 

 ribs are subsessile. The fourth vertebra bears a pair of feeble 

 inferior apophyses. The lower pharyngeals are united by a 

 straight suture. 



* Eigenmann and Bray say, " No type was indicated for Acara until 

 Gill in 1858 restricted it by exclusion of species of Astrunotus and 

 Cichlasoma to Heckel's Acara crassispinis. But it has since been deter- 

 mined that the Acara crassispinis of Heckel is a syuomm of Lvbotes 

 ocellatus, Agassiz, which is the type of Astronotus. Tlie name Acara is 

 therefore the exact syntmyui ot Astrojioftts.^' This argument appears 

 unsound. After removing from Heckel's genus tlie species Avliich belong 

 to Astrmwtus, Cichlosovia, and Acaropsis, I use Acara for the remainder, 

 regarding Gill's restricticin of the name Acara to a species which was 

 already the type of another genus as invalid. 



