(Contributions from the Zoological Laboratory of Indiana University, 

 No. 140.) 



24. On New Species of Fishes from Colombia, 

 Ecuador, and Brazil 



By Carl H. Eigenmann and Ar'hur Fenn 



Rhoadsia minor Eigenmann and Henn, sp. nov. 

 Type 95 mm. I. U. M. 13419. 



Paratypes, 3, 98-104 mm.; 88, 10-59 mm., I. U. M. 13420. 



Mindo, Province of Pichincha, Ecuador. Rio Blanco of Rio Esmeraldas 

 system, elevation 4,000 feet. Coll. Arthur Henn. 



Head 3.8; depth 2.8-3; D. 11; A. 28-30; scales 9-15 + 25-8; eye 1.2-1.4 in 

 snout, 3.8-4 in head and 1.3-1.6 in interorbital in mature specimens. Gill 

 rakers 10 -f- 14. 



Slender, compressed; profile oblique to end of occipital process, thence 

 arched to dorsal. Predorsal area narrow, without a median series of scales, 

 those of the two sides overlapping. Occipital process elongate, with five or 

 six scales along its side. 



Dorsal placed slightly in advance of middle of entire length, fourth and 

 fifth rays longest, reaching to caudal base; adipose well developed; origin 

 of anal under last rays of dorsal, 4th to 7th rays prolonged forming an anterior 

 lobe; pectorals just to ventrals, the latter overlap considerably on the anal. 



Scales regularly imbricate, lateral line developed on first 14 or 15 scales, 

 caudal naked, one or two inconspicuous rows of small scales developed on 

 about the first ten rays of the anal. ^ 



Teeth and maxillary greatly modified in development. Maxillary in 

 young without teeth; on the premaxillary a series of five-pointed or six-pointed 

 incisors, opposing identical incisors in the mandible. Maxillary in mature 

 specimens elongate, slender, reaching below vertical from posterior margin 

 of the orbit. Maxillary teeth in mature specimens consist of 13 conical spike- 

 like incisors arranged along the anterior margin in addition to two tricuspid 

 incisors near the premaxillary symphysis. Teeth of the premaxillary in two 

 series, an outer series of one or two conical cusps in each premaxillary; these 

 have no opponents in the mandible but simply project downwards and out- 

 wards from the snout. An inner series of five tricuspid incisors in each pre- 

 maxillary interlocking with the incisors of the mandible. In each ramus of 

 the mandible are ten teeth, the two innermost are conical and recm*ved, then 

 three conical; the first is vertical, the outer two slant forward. At right 

 angles because of the square mouth are five tricuspid incisors meeting their 

 identical opponents in the premaxillary. 



Exact field notes of color were not preserved. Coloration in life brilliant, 

 the anal a combination of bright red and yellow, dorsal paler yellow, an oblong 

 or deltoid spot of bright black in the mid-lateral line below the last rays of 

 the dorsal. This is often produced as a straight line to the base of the caudal. 

 Very young specimens possess a circular spot on the caudal base. This be- 

 comes obsolete with age and is lost when 40 mm. is attained. There is no 

 indication of the lateral subdorsal spot below 28 mm. An obscure dark 

 oval, humeral spot behind operculum followed by a vertical bar. Upper part 

 of opercle silvery white, lower part deep black. 



(231) 



