270 PROCEEDINGS OF THE ACADEMY OF [Apr.^ 



slightly elevated cutaneous rims, though posterior pair larger and 

 placed opposite and within space between front edges of eyes. Inter- 

 orbital level. Preopercle with a cluster of 5 more or less concealed 

 large conic spines, partly eractile. Opercle with 2 similar, only 

 smaller, spines. 



Gill-opening small, lateral, just before pectoral base. 

 Body naked, covered with smooth skin. T.. 1. complete, simple 

 or without branches, and median along side. 



Dorsal origin a little nearer caudal base than pectoral origin, 

 first branched ray longest, and depressed fin extends about f to- 

 caudal base. Anal inserted just behind dorsal base, first branched 

 ray longest or extends back beyond tip of last so that fin reaches 

 y to caudal base. Caudal slightly emarginate, elongate and with 

 well-developed fulcra. Pectoral low, broad, extend about | to ven- 

 tral. Latter inserted well before dorsal origin or about midway 

 between pectoral origin and caudal base, and extends back f to anal 

 origin. Vent midway between depressed pectoral tip and anal origin. 



Color in alcohol pale or very light brownish, shading to whitish 

 on lower or under surface. Predorsal region with about four series 

 of dusky irregular spots. From behind dorsal only a few median 

 dusky spots, though upper surface of head with spots of similar size 

 to those of predorsal region. ' One of these blotches marks opercular 

 spines and another preopercular spines. Also a dark spot above 

 pectoral base. Following course of 1. 1. 16 dusky blotches, at first 

 small, then gradually larger until maximum size obtains on side 

 of caudal peduncle. Along upper extent of this series also several 

 smaller dark scattered spots. Fins all pale or whitish, several obscure 

 spots of dusky on dorsal, caudal, and pectoral base, others uniform. 

 Iris slaty. 



Length 93 mm. 



Type, No. 39,344, A. N. S. P. Rupununi River, British Guiana. 

 J. Ogilvie. 



This species resembles Ochmacanthus flahelUferus Eigenmann, l)ut 

 differs in its dentition, coloration, and position of its fins. 



{Td^fi, row; ^r^/za, spot; with reference- to the series of large dark 

 lateral blotches along the lateral line.) 



CALLIOHTHYID^. 

 Callichthys callichthys (I.innisus). 



One example 128 mm. 



Hoplosternum thoracatum (Valenciennes). 



One example 70 mm. 



