386 MR. C. TATE REGAN OX [A-pr. 10, 



to the base of ventral. Yentrals 9-rayed, originating in advance 

 o^the vertical from the middle of the dorsal. Caudal forked. 

 Caudal peduncle deeper than long. Silvery ; a blackish spot on 

 the caudal peduncle, another on the basal part of the dorsal fin ; 

 fins pale yellowish. 



Three specimens, 70-100 mm. in total length. 



There are examples of this species fiom Dominica in the British 

 Museum collection, but it has not yet been recorded from othei- 

 localities. 



" Plentiful in the Ravines of the Streatham Lodge Estate." 



10. Oarapus fasciatus Pall. 

 " Cutlass Fish." 



" Found in the Bejucal Swamp and Cumuto. 



" Colour : head and back dark olive-green ; sides with alternate 

 oblique bars of blackish and grey ; anal fin blackish ; head and 

 body sprinkled with metallic specks." 



Hob. Paraguay to Guatemala. 



1 1 . Arius spixii Ag. 



" A silver-grey Cat-fish, found in bi-ackish water at the mouth 

 of the river Caroni, where it attains a large size." 

 Hah. Brazil ; Guiana ; Venezuela. 



12. Arius herzbergii B1. 



Hah. Brazil ; Guiana ; Venezuela. 



13. PiMELODUs (Rhamdia) wilsoni Gill. 



Depth of body about 5 in the length, length of head 4|-4i. 

 Head covered with skin, nearly as broad as long. Snout twice as 

 long as eye, the diameter of which is 6 in the length of head ; 

 interorbital width 2^. Jaws equal anteriorly ; maxillary barbel 

 extending to middle, or even beyond the end of adipose fin ; outer 

 mandibulary barbel about reaching end of pectoral. Occipital 

 process 2^-3 times as long as broad, extending back beneath the 

 skin, separated posteriorly by a distance about equal to its own 

 breadth from the basal shield of the dorsal spine. Dorsal I 6 ; 

 spine slender ; middle branched rays a little more than | the 

 length of head ; free edge of the fin convex. Adipose fin com- 

 mencing a short distance behind the dorsal and extending nearly 

 to the caudal, its length 2i-2| in that of the fish. Anal 1 1 , low 

 anteriorly, rounded posteriorly, the rays gradually increasing in 

 length to the eighth or ninth, which is i the length of head. 

 Caudal forked ; lobes of equal length, the upper pointed, the lower 

 rounded. Pectoral spine with inner edge finely serrated, about '^ 

 as long as the fin, which is 4 the length of head. Ventrals 

 extending |~i of the distance from their base to the origin of 

 anal. 



Back olive-green or grey ; sides blackish blue splashed with 

 whitish ; lower parts white ; body sometimes covered with dark 



