670 ON NKW SOUTH- AMERICAN FISHES. 



10. Arges cirratus, sp. n. 



Length of head 3f in the length of the fish. Interocular width 

 rather more than distance from eye to posterior nostril, rather 

 less than | the length of head. Nasal flap produced into a barbel 

 which is as long as the diameter of the eye ; maxillary barbel not 

 quite reaching gill-opening ; teeth of outer series of preemaxil- 

 laries unicuspid, acute ; mandibulary teeth bicuspid. First dorsal 

 ray f the length of head ; pectoral extending to base of ventral ; 

 ventrals inserted below anterior part of dorsal, nearly reaching 

 anal. Spine of adipose fin well developed, movable, connected" 

 by a membrane with the caudal peduncle, inserted at a distance 

 from caudal equal to about | the length of the middle rays of 

 that fin. Distance from tip of snout to origin of dorsal fin 2|- 

 in the length of the fish, from base of last anal i-ay to caudal 5f . 

 A few large dark spots on body ; a blackish bar across middle of 

 caudal fin. 



A single specimen, 24 mm. in total length, from the Rio 

 Condoto, Rio San Juan, S.W. Colombia, collected by Mr. G. 

 Palmer. 



EXPLANATION OF THE PLATES. 



Plate LXXV. 



Fig. 1. Chcetostomns lepfiorus. 

 Fig. 2. „ ^aucispinis. 



Fig. 3. „ palmeri. 



Plate LXXVI. 



Fig. 1. Xenocara multispmis. 

 Fig. 2. „ heterorhynchus. 



Fig. 3. Flecostomus Jiondce. 



Plate LXXVII. 



Fig. 1. Oxyloricaria tamance (Xf). 

 Figs, la, ih. Heads of d* & ? • 

 Fig. 2. O. leightoni. 

 Fig. 3. Otocinchis maculipinnis {X2). 



