﻿A new type of Scale in Fishes, developed in 

 the Pterobryconinae 



At Boca de Raspadura, a small village at the junction of the San 

 Pablo with the Kaspadura and near the continental divide between 

 the Atrato and San Juan basins, collections were made in the com- 

 paratively barren Raspadura and San Pablo Rivers. Nothing of 

 note M^as secured that was not also obtained in other parts of the 

 Raspadura, Quito and Atrato Rivers. Behind the town is a small 

 brook, not more than five feet wide, with vertical walls^veral feet 

 high and hidden by overgrowing shrubs and weeds. The use of a 

 cheese-cloth net in a little pool of this brook yielded a startling lot 

 of remarkable fishes. 



Nematohrycon palmeri, heretofore known only from the Pacific ; 

 slope, was taken here. 



BunocepJialus colomhimius, described in the first part of this 

 paper, extends the known distribution of this genus for more than 

 a thousand miles. This was also taken at Quibdo some time later. 



Thoracocharax hrevis, a new species, helps to solve the question 

 arising from the presence of this genus on the Pacific side of 

 Panama. 



To this list of notables must be added a new subfamily of Char- 

 acins represented by a single minute specimen ornamented, as far 

 as I am aware, with an entirely new type of scale. 



PTEROBRYCONIN^ Subf . nov. - 



PTEROBRYCON Gen. no v. 



Dentition as in tlie Tetragonopterinfie. Gill-membranes united, free 

 from the isthmus. Dorsal and anal rounded, the middle rays longer than 

 those before or those after them, last anal ray produced. Caudal naked ; 

 one scale on each side of the shoulder modified ; lateral line incomplete. 



This genus, as far as I know, is unique among fishes in the prolonga- 

 tion of some of the scales into long structures, enlarged and ocellated at 

 the end, thus reniotelj^ recalling an ocellated feather in a peacock's tail. 



Pterobrycon landoni gp. nov. 



Type, 25 mm. Boca de Raspadura. C. M. No. 5051. 

 Head, 3.5: depth 4+; D. 10; A. 17 ; scales?; lateral line incomplete; eye 

 2.5. About 18 scales in front of the dorsal. 



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