THE EYES OF THE BLIND VERTEBRATES OF 

 NORTH AMERICA. III. 



THE STRUCTURE AND ONTOGENIC DEGENERATION OF THE 



EYES OF THE MISSOURI CAVE SALAMANDER, AN 



ACCOUNT BASED ON MATERIAL COLLECTED 



WITH A GRANT FROM THE ELIZABETH 



THOMPSON SCIENCE FUND?- 



CARL H. EIGENMANN AND WINFIELD AUGUSTUS DENNY. 



A SINGLE specimen of a salamander was discovered in Rock 

 House Cave, Barrie County, Missouri, by Mr. F. A. Sampson 

 in July, 1891. The specimen was described by Stejneger in the 

 Proceedings of the U. S. National Museum, Vol. XV, p. 115, 

 as Typhlotriton spelaeus. His diagnosis reads as follows : 

 " Vertebrae opistocoelous ; parasphenoid teeth ; vomerine teeth ; 

 eyes concealed under the continuous skin of the head ; tongue 

 attached in front and along the median line, free laterally and 

 posteriorly ; maxillar and mandibular teeth small and numer- 

 ous ; vomerine teeth in two strongly curved series ; para- 

 sphenoid patches separate ; nostrils very small ; toes five ; six- 

 teen costal grooves, or eighteen if counting the axillary and 

 groin grooves ; tail slightly compressed, not finned ; toes 

 nearly half webbed ; vomerine teeth in two F-shaped series 

 with the curvatures directed forward ; gular fold strong, very 

 concave anteriorly ; color uniformly pale." 



Stejneger fully appreciated the value and nature of his dis- 

 covery. He says : " Although many of our salamanders are 

 known to inhabit caves, this seems to be the only one, so far 

 discovered, which, like some of the other animals exclusively 

 living in caves, has become blind or nearly so." This was 

 written by him before he discovered the Typhlomolge in the 

 underground streams of Texas. 



1 Contribution from the Zoological Laboratory of the Indiana University, No. 31. 



33 



