154 MR. C. TATE REGAN ON SOUTH- AMERICAN [Mar. 7, 



the teeth depressible. Upper surface of head usually scaly about 

 to the level of the orbits ; cheeks and opercular bones scaly ; 

 posterior border of prseoperculum finely denticulated. Gill- rakers 

 short, few. A single dorsal fin, with XXII-XXIV 10-13 rays. 

 Anal with III 7-10 rays. Pectoral symmetrical, rounded, with 

 about 17 rays; ventrals behind the bases of the pectorals. Caudal 

 rounded. 



Five species from South America. 



Synopsis of the Species. 



I. 55-60 scales in a longitudinal series below tlie lateral line. 



Maxillary extending beyond middle of eye 1. ocellatiis. 



Maxillary extending to below anterior margin of eye 2. semifasciatus. 



II. 66-70 scales in a longitudinal series below the lateral line. 



A. Maxillary extending a little beyond anterior margin of 



eye. 

 Diameter of eye 4-5 in the length of head, interorbital width 2^-3 



(in specimens of from 85 to 250 mm. in total length)" 3. reticuJatus. 



Diameter of eye 4^ in the length of head, interorbital width 3^ 



(in a specimen of 140 mm. in total length) 4. punctulatus. 



B. Maxillary extending to below anterior j of eye; diameter 



of eye 3J in the length of head and nearly equal to the 

 interorbital width (in a specimen of 150 mm. in total 

 length) 5. ct/anonotiis. 



1 . Batrachops ocellatus. 



Boggiania ocellata Perugia, Ann. Mus. Genova, (2) xviii. 1897, 

 p. 148 ; Pellegr. Mem. Soc. Zool. France, xvi. 1903, p. 371 (1904). 



Depth of body 4 in the length, length of head 3|. Diameter 

 of eye 5| in the length of head, length of snout 4, interoi-bital 

 width 2i. Xosti-il equidistant from eye and tip of snout. 

 Maxillary extending nearly to below posterior margin of eye ; 

 depth of prfeorbital k the diameter of eye. Anterior teeth 

 forming 3 series in each jaw. 7 or 8 gill-rakers on the lower part 

 of anterior arch. Scales feebly denticulated except on the head, 

 the lower parts of thorax and abdomen and anteriorly above the 



lateral line, 74 j-g, 60 in a longitudinal series below the lateral 

 line, 4 between last dorsal spine and lateral line, 2 between upper 

 and lower lateral lines. Dorsal XXII 11, the spines subequal 

 from about the eighth, the last nearly ^ the length of head. Anal 

 III 8. Pectoral j, ventral nearly |- the length of head. Caudal 

 peduncle | as long as deep. Olivaceous, with indistinct darker 

 longitudinal stripes along the series of scales ; a blackish ocelkis 

 on the upper part of the base of caudal. 



Upper Paraguay. 



Through the kindness of Dr. R. Gestro, of the Genoa Museum, 

 I have been able to examine the type of this species, which 

 measures 265 millimetres in total length. The posterior margin 

 of the prgeoperculum is denticulated and the gill- membranes are 

 free from the isthmus, as in other species of this genus. 



