152 MR. C, TATE REGAN ON SOUTH-AMERICAN [Mar. 7, 1. A Revision of the Fishes o£ the South-American Cichlid Genera Crenacara, Batraohops, and Crenicichla. By C, Tate Eegan, B.A., F.Z.S. [Received Februarj-7, 1905. | (Plates XIY. & XV.*) The genei"a dealt with in the following revision are distinguished from all other Cichlid^ by the denticulated posterior margin of the preeoperculum. I have given a list of the specimens in the British Museum Collection on which my descriptions are based, with the total length in millimetres of each. Crenacara. Crenicara Steind. Sitzb. Ak. Wien, Ixxi. 1875, p. 99 ; Eigenm. & Bray, Ann. Ac. N. York, vii. 1894, p. 619 ; Pellegr. Mem. Soc. Zool. France, xvi. 1903, p. 169 (1904). Dicrossus Steind. t. c. p. 102 ; Eigenm. & Bray, t. c. p. 620; Pellegr. t. c. p. 170. Body ovate or elongate, more or less compressed ; scales large, ctenoid. Two lateral lines ; scales of the lateral line of the same size as those above and below it. Mouth small ; Jaws equal anteriorly ; maxillary not exposed ; a band of small conical teeth in each jaw ; upper surface of head scaly to between the orbits ; cheeks and opercular bones scaly ; posterior border of p'rseoperculum finely denticulated. Gill-rakers short, few. A single dorsal with XIV-XYII 8-9 rays. Anal with III 7-8 rays. Pectoral asymmetrical, with 15 rays; ventrals a little behind the bases of the pectorals. Caudal rounded. Two species from the Amazon and Guiana. 1. Crenacara punctulata. Acara punctulata (part.) Glinth. Ann. Mag. Nat. Hist, xii, 1863, p. 441. Crenicara elegans Steind. Sitzb. Ak. Wien, Ixxi. 1875, p. 99, pi. i. fig. 1. Crenicara punctulata Pellegr. Mem. Soc. Zool. France, xvi. 1903, p. 169 (1904). Depth of body 2^-2|-in the length, length of head 3^. Snout a little shorter than eye, the diameter of which is 2| in the length of head and equals the interorbital width. Depth of prseorbital | the diameter of eye. Maxillary not extending to below the eye ; jaws eqvial anteriorly ; cheek with 3 or 4 series of scales, none on the prseoperculum ; 6 gill-rakers on the lower part of anterior arch. Scales 29 |, 1 between lateral line and * For explanation of the Plates, see p. 168.