MEMOIRS 



OF THE 



OAENEGIE MUSEUM. 



VOL. VI. NO. III. 



THE GYMNOTID EELS OF TROPICAL AMERICA.^ 



By. Max Mapes Ellis. 



(Plates XV-XXIII.) 



Introduction. 



In 1909 I undertook the identification of the specimens of Gymnotid eels 

 collected by Dr. Eigenmann in British Guiana. Three new species were found, 

 Sternarchus leptorhynchus, Porotergus gymnotus, and Gytmiorhamphichthys hypo- 

 stomus. The second and third of these represented new genera. Numerous 

 specimens of Eigenmannia macrops (Boulenger), a species listed but once before, 

 were also part of this collection. In all five species of Gymnotids were added to 

 the fauna of Guiana. 



Subsequently all of the Gymnotidce collected by Mr. John D. Haseman of the 

 Carnegie Museum Expedition to Central South America were received for study. 

 As these collections contained several new species and specimens of many little 

 known species, a revision of the entire family was begun. Mr. Haseman visited 

 many new localities, and his collections were of particular value in the study of the 

 geographical distribution of these fishes. 



While engaged in the systematic revision several interesting questions arose. 

 Three in particular may be mentioned: (1) the use of the mental filaments of 

 Steatogenes elegans (Steindachner) ; (2) the relation to their general ecology of the 



1 Contributions from tlie Zoological Laboratory of Indiana University, under the direction of C. H. 

 Eigenmann, No. 116. A tliesis accepted as in part fulfilling tlie requirements for the degree of Doctor of 

 Philosophy, June, 1911. 



Tliis paper is a partial report on the Gimbel Expedition to British Guiana and the Carnegie Museum 

 Expedition to Central South America. 



109 



