﻿70 BLIND VERTEBRATES AND THEIR EYES. 



THE AMBLYOPSID^. 



The Amblyopsidse are a small family of fishes, first brought to the notice of 

 naturalists by W. T. Craige, who presented a specimen to the Philadelphia Academy 

 in 1842. De Kay, "Natural History of New York" (Reptiles and Fishes, p. 187, 

 1842), gives a brief description of Amhlyopsis spelmts. It was followed at once by 

 articles by Wyman (1843 and later, 1850, 1854 a and b) and other articles by Thomp- 

 son (1844) and by Telkampf (1844). Renewed interest in the Amblyopsidae was 

 aroused by Agassiz's discovery of an epigean relative, Chologaster cornuius, in the 

 ditches of rice fields in South Carolina. 



TyphUchthys suhterrancus was described by Girard in 1859 from a well near 

 Bowling Green, Kentucky ; Chologaster agassizil, by Putnam from a well at Leba- 

 non, Tennessee, in 1872 ; Chologaster papilli/crus, by Forbes in 1882. In 1898 the 

 present author described TyphUchthys rosce, and a short time afterwards he 

 demonstrated that this species is generically distinct from TyphUchthys, naming 

 it TrogUchthys. More recently (1905) he described TyphUchthys osborni and 

 TyphUchthys wyandolle. 



RELATIONSHIPS OF THE AMBLYOPSID^. 



The Amblyopsidae are members of the order Haplomi, first characterized by 

 Cope.' They have recently been defined by Boulenger, as follows : 



Air-bladder, if present, communicating with the digestive tract by a duct. Opercle well devel- 

 oped. Pectoral arch suspended from the skull; no mesochorochoid. Fins usually without, rarely 

 with a few spines; ventrals abdominal, if present. Anterior vertebrae distinct, without Weberian 

 ossicles. 



The order consists of a number of families of wliich the Galaxiidse and Aplochi- 

 tonidse are found in the fresh waters and occasionally in the oceans of the south 

 temperate zone; the Scopelidae are found pelagic and abysmal in the ocean, the 

 Kneriidae in Africa, the Dalliidai in Alaska and Siberia, the Poeciliidae in fresh 

 water and along the shores of the tropical and temperate zones, and the Esocidae in 

 fresh waters of the north temperate zone. 



The Amblyopsidae are distinguished from the other families by the doubling 

 forward of the alimentary tract, the opening of the oviduct and anus being placed 

 close behind the throat, in front of the pectorals. 



The genera of the Amblyopsidje may be distinguished by the following char- 

 acters : 



a. Ventral fins present ; pyloric cceca 2 or 3 Amhlyopsis 



aa. Ventral fins absent 



h. Eye a vestige ; pyloric cceca 2 



c. Sclera with cartilages ............ TrogUchthys 



cc. Sclera without cartilages ........... TyphUchthys 



bb. Eye well developed; body pigmented; pyloric coeca 4 Chologaster 



' Proc. Amer. Assoc, .^dv. Science, Indianapolis, 1872, 328 and ^^;^. 



