92 



PROCEEDINGS OF THE ACADEMY OF 



On favorable report of the Committee, the following paper was 

 ordered to be published : 



On some New Species of FISHES obtained by Prof. Orton from the Maranon, 

 or Upper Amazon, and Napo Rivers. 



BY THEODORE GILL, M. D, PH. D. 



In an expedition to the Andes of Ecquador and Peru, and thence across 

 the continent of South America, under the command of Prof. James Orton, a 

 considerable zoological collection was formed, and the fishes being submitted 

 to the writer for determination, the following appeared to be undescribed. Of 

 previously known species, the most noteworthy were Chalcinus nematurus 

 Kner, Gasteropelecus stellatus Kner, Pimeletropis lateralis Gill, and Cyclopium 

 Humbolrftii Swains. 



Subfamily TETRAGONOPTERIX^E. 



Tetragonopterus Ortonii Gill. 



[D. 11. A. 34. L. 1. 31. 



The height is contained about twice in the distance between the snout and 

 the median margin of the caudal, and the head about four times in tne same, 

 or three and a half in the length, exclusive of the caudal. The profile is con- 

 cave at the parietal region ; the interorbital area is transversely convex. The 

 diameter of the eye is contained two and a half times in the head's length. 

 The supramaxillary extends nearly to the vertical of the anterior margin of the 

 pupil. The dorsal is immediately behind the roots of the ventrals ; its height 

 equals about f of that of the body. The pectoral equals f the length of the 

 head ; the ventrals extend to the anal. 



The scapular spot is indistinct ; that at the base of the caudal well defined. 



Most nearly related to T. orbicularis Val. 



I dedicate this species to Prof. Orton. 



Astyanax Carolina Gill. 



D. 11. A. 26. V. 9. L. lat. 37 38 . 



5 



The height of the body enters 2| times in the length, exclusive of the cau- 

 dal ; the length of the head 3f ; the profile to the convex snout is rectilinear, 

 and the interorbital space scarcely arched ; the latter is as wide or rather 

 wiiler than the diameter of the orbit, and about a third of the head's length. 

 The maxillary ceases in front of the vertical of the front of the pupil, and 

 the end of the first suborbital. The dorsal commences considerably behind 

 the origin of the ventrals. The pectorals extend beyond the same point, and 

 the ventrals to the anus. The usual silver tinged lateral band, and humeral 

 and caudal spots exict, but are very faint. 



The species is represented by a single specimen, 4] inches long, taken in 

 the river Napo or Maranon and belongs to the same group as A. peruvianvs 

 (Tetragonopterus peruvianus M. T.), A. humilis (T. humilis Gthr.), A. scabrt- 

 pinnis (T. scabripinnis Jen.), A. maculatus (T. maculatus M. T. ex L.), A. Bre- 

 voortii (Poec. Brevoortii Gill), A. fasciatus (T. fasciatus Cuv.) A. microstoma (T. 

 microstoma Gthr.) and allies. 



Subfamily HYDROCYONIN'.E. 

 R^eboides Myersii Gill. 

 P. 10. V. 0. D. 12. A. 53. 

 The height enters two and a half times in the length, exclusive of the cau- 



[Aug. 





