534 EIGENMANN 



1889. I. The Eyes of ^/«(5/yc>/5/c/^. Arch. f. Entwickelungsmech., 



VIII, pp. 545-617, plates xi-xv. 

 1900. II. The Eyes of Typhlomol^e rathbunt Ste.]ne^eY. Trans. 



Am. Microsc. Soc, xxi, pp. 49-60, plates iii and iv. 

 1900. III. The Structure and Ontogenic Degeneration of the Eyes 



of the Missouri Cave Salamander. Biological Bulletin, 11, pp. 



33-4O5 Pl^te. 



HABITS OF RHINEURA. 



Rhineura Jloridana Baird is a legless, burrowing, blind Amphis- 

 baenian lizard. It is abundant in some parts of Florida. The largest 

 individual I secured measured 340 mm. The tail is very short, flat- 

 tened dorsoventrally, and the upper surface of its distal half is strongly 

 rugose. Each of the transverse rings is here, w^ith numerous tuber- 

 cles. The mouth is small ; the tip of the lower jaw is some distance 

 behind the tip of the upper jaw. In shape, color and arrangement of 

 its dermal plates it strikingly resembles an earthworm. This resem- 

 blance is heightened by its vermiform progression through the rhythmic 

 movements of its annular plates. Its forward and backward locomo- 

 tion in its burrows is entirely due to this vermiform movement. It 

 burrows rapidly, and for this its small, hard, conical head is well 

 adapted. The point of the snout is turned down and the head then 

 thrust upward in a rooting fashion. An individual will readily disap- 

 pear in from half a minute to two minutes. By placing it in a glass 

 vessel partly filled with earth its burrowing can readily be seen from 

 below. If placed on a bare surface it for a time will wriggle actively 

 from side to side, snake fashion, but without much effect as far as loco- 

 motion is concerned. The tail, under such circumstances, is dragged 

 behind, as if it had no vital connection with the head. Rarely there 

 is a suggestion of a bracing with the tip of the tail against the floor. 

 In one minute an individual moved 250 mm. In an attempt at root- 

 ing, after the snout had become wedged under the edge of an immov- 

 able object, the whole body to the tip of the tail was repeatedly lifted 

 off the floor. 



Rhineura is, as far as I know, one of the two blind vertebrates that 

 have been found in the fossil state. Baur described a species of Rhi- 

 netcra (R. hatcherit) and another Amphisbaenian {^Hypsorhina an- 

 tigud) from the Miocene beds of South Dakota. Baur says nothing 

 concerning the dermal plates, so that nothing is definitely known about 

 the eyes of this fossil Rhineura. Since all the genera of the family 

 Amphisbsenidse have rudimentary eyes, the eyes were veiy probably 

 degenerate before the genera became separated. It seems quite cer- 



