﻿J6 



IXDIAXA rXITEESITT STUDIES 



its outer ray abruptly produced, 3.5-5 hi tbe length, reaching to origin or 

 third fifth of ventrals ; origin of ventrals liel"V\- the first or third dorsal 

 ray: rentrals lancet shaped, reaching slightly beyond the anus in both 

 the largest male and the largest female : anal short, lower in the male 

 than in the female, the first and still more the second membrane wider 

 than the rest, the last rays being crowded together, not notably prolonged: 

 distance of last anal ray from caudal five and one-half tr» <ix in the 

 length: adipose a low fold, about a third of the length, teiuiinariiiu in a 

 small movable spine attached to the bach by a meml>raiie: d'a-sal very low. 

 the first ray slightly produced. 1.5 to 1.25 in the head, the reniaiidiii: rays 

 subequal. the tip of the second usually not extending to the tii's Mf -'ime 

 of the following ones, the second ray half the length of the Iiead ]l^'^liud 

 anterior nares : distance between dorsal and snout about 2y> in tlie U^niiTli : 

 outer caudal rays produced, the fin otherwise lunate: outer tt" rli mi' the 

 premaxillary slender, pointed, those of the lower jaw nearly e'lnally 

 bilobed. 



Blackish, faintly marbled in adult, more distinctly so in the yoimg; 

 base of caudal dark, faint cross-marblings on the rest of the fin. 



TyiDe, a male 76 mm. over all. Caldas. CM. No. 4866. 



Paratype. a female 75 mm. over all and thirteen smaller specimens 

 both male and female from Caldas in the Dagua and a small tributary 

 CM. No. 4S67 a-g. I.U.M. Xo. 12170 a-g. 



Paratypes. seven specimens, the largest 3S mm. Istmina. CM. Xo. 

 4865. I.U.M. Xo. 12709. 



This species associated with C. trifasciatum can readily be distin- 

 guished by the nasal barblet. the longer barbel, different ventral and posi- 

 tion of the ventrals. 



The small specimens from Istmina were taken from a minute rivulet. 

 The contrast between the light and dark ma ri fling is much greater than in 

 the Caldas specimens. The na-;il li-irb^N ai^"^ inMre^ iirominent. Regan has 

 recently described a Cjiclopiu/n ■ <-l rr<it " m :~ iv^^m C'aidnto. It is imssible 

 that this is veiitralc. in which case the present species should go by the 

 name. C. cirraium. 



14. Megalonema xanthum sp. no v. 



Head 3.75 ; depth 5.33 : D. 7 : A. 3.9 : eye 5 in head. 1.25 in interucular. 

 slightly nearer margin of opercle than t<i rip of snout. 



Elongate: profile steep and nearly straight. Head covered with thin 

 skin : occipital process narrow, not extending half way to dorsal, an inter- 

 neural intervening between it and the dorsal : top of head with some 

 reticulating canals; depth at base of occipital crest slightly more than 

 snout and eye ; head a little wider than deep : eye with a free, oval orbital 

 rim : snout projecting, equal to orbital diameter, ov two-thirds that. Teetb 

 in very narrow bands, the upper band narrowed at middle, almost sepa- 

 rated into two patches, without retral angles: teeth of upper jaw movable, 

 slightly larger than those of lower jaw, which are a little firmer. 



Fourteen rakers on the lower arch. Branchinstegal membrane free 

 from the isthmus, overlapping mesially: maxillary barbel extending nearly 



' Proc. Zool. Soc. London. 1912. 



670. 



