PARKER: OPTIC CHIASMA IN TELEOSTS. 



225 



therefore, be adopted here. I shall begin with a consideration of the 



soles. 



The Soleidae, according to Jordan and Evermann ('96-00, p. 2692), 



may be divided into three subfamilies : the Achirinae, or American 



soles ; the Soleinae, or European soles ; and the Cynoglossinae, or 



tongue fishes. The Achirinae and Soleinae have their eyes on the right 



side, that is, they are dextral ; the Cynoglossinae are sinistral. I have had 



the opportunity of studying representatives of all three subfamilies, 



and the positions of their optic nerves at the chiasmata are given in 



Table II. 



TABLE II. 



Of the American soles two species were examined, Achirus lineatus 

 and A. fasciatus. All specimens were dextral, as is typical for this sub- 

 family, and in both species individuals with the left nerve dorsal, and 

 others with the right nerve dorsal were found. The numbers given in 

 the Table indicate an approximate equality in the occurrence of these 



1 Material supplied by the United States Commission of Fish and Fisheries. 



2 Material from the collections of the Museum of Comparative Zoology. 



