110 MEMOIRS OF THE CARNEGIE MUSEUM. 
frequent injury and subsequent regeneration of the caudal region of the members 
of this family; and (3) the mode of locomotion. 
These questions and others made a study of the living fishes very desirable 
before the completion of this monograph. This matter was laid before Mr. Jake 
Gimbel of Vincennes, Indiana, who generously agreed to finance an expedition to 
British Guiana. In August, 1910, the writer, with Mr. William Tucker, a volunteer 
assistant, sailed via the Quebee Line for Georgetown, British Guiana. Studies of 
the living Gymnotide were made in the trenches in and about Georgetown. A trip 
was made to Hubabu Creek, the first inland fresh-water creek emptying into the 
Demerara River. The Demerara is still brackish at the mouth of Hubabu Creek. 
Two excursions were also made to Gluck Island in the Essequibo River opposite 
Rockstone. This island is about one hundred miles from the coast. Collections 
were also made in the harbor and on the mud-flats at Georgetown. A new Gym- 
notid, Porotergus gimbeli, was added from Hubabu Creek. 
During the spring of 1910, Mr. Bertoni of Puerto Bertoni, Paraguay, sent 
Indiana University a small collection of fishes from the upper Parand River. 
Among these was a specimen of the new species Gymnorhamphichthys hypostomus. 
The several collections mentioned, as well as the material in the Indiana 
University Museum, offered an excellent opportunity for a revision of this family. 
Twenty-two of the twenty-seven known species are in the collections examined, 
all of the twenty-two being in the collections of the Carnegie Museum. I wish to 
thank Dr. C. H. Eigenmann for his many helpful suggestions and criticisms. I am 
deeply indebted to Mr. Jake Gimbel for his generous support of the trip to Guiana, 
without which certain sections of this monograph could not have been written. 
I am also under obligations to the Quebec Steamship Line of Quebee and London, 
and Sproston’s Limited of Georgetown, for their grants of transportation, and to 
Mr. Bernard Conrad of Georgetown, who aided me in many ways during my stay 
in Guiana. 
HIstory OF THE LITERATURE OF THE GYMNOTID”. 
The first scientific record of any species of this family is that of Georg Marcgraf 
(1648), who described as “‘carapo”’ the species now known as Gymnotus carapo. 
His fish came from Brazil. The name Gymnotus carapo was given to this species 
by Artedi in 1738. He placed it under “‘Ordo I, Malacopterygii,”’ with the simple 
description, ‘‘Membrana branchiostega ossiculis quinque. Pinna dorsalis nulla”’ 
(Genera, p. 25, and Synonymia, p. 43). Linnzeus under his A podes listed Gymnotus 
carapo and asiaticus in the tenth edition, and Gymnotus carapo, electricus, albifrons, 
rostratus, and asiaticus in the twelfth edition of the Systema Nature. 
The beginning of real interest in this group of fishes was about forty years 
before the appearance of the twelfth edition. In 1729 Richter published the first 
scientific article on the electric eel. This stimulated the study of the Gymnotide. 
As a result, scarcely a decade has passed since Richter’s paper appeared without 
the publication of some contribution bearing upon the electric eel or its relatives. 
