THE NAUTILUS. 



Yet of all the species and in spite of their seemingly great 

 powers for existing under such harsh conditions as those of 

 flood, shifting stream bed and chemical erosion, none seems 

 to have been able to survive the river conditions of the middle 

 Tennessee. Not one, present study appears to show, has 

 rounded Walden Ridge and become located in the streams of 

 central Tennessee or of Alabama. Nor, the literature to the 

 contrary, is there clear evidence that Go niolases characteristic 

 of central Tennessee thrive east of the mountains. 



A NEW CHITON FROM SOUTHERN BRAZIL. 



BY W. H. DALL. 



Among some shells sent for identification by Dr. Florentino 

 Felippone of Montevideo is a chiton with quite unique sculp- 

 ture, and a combination of characters which does not admit 

 of its being placed in any of the subdivisions which have 

 hitherto been proposed in the restricted group of Chitonidae. 

 I therefore suggest for it the following designation. 



TYPHLOCHITON. 



Chiton without dorsal eyes, the end valves with numerous 

 slits, the intermediate valves with one slit on each side; the 

 insertion plates externally grooved; the eaves not spongy; 

 the gill rows long but not extending to either head or tail, the 

 margin of the sinus entire. 



Type: 



TYPHLOCHITON PELIPPONEI n. sp. 



Chiton with brownish velvety girdle with rare minute, 

 short, silvery spicules sparsely irregularly distributed; gills 

 about 25 on each side with the ends of the series separated by 

 a marked vacant space from both head and tail ; valves rather 

 acutely ridged and medially posteriorly produced; the an- 

 terior valve with ten, the intermediate valves with one slit on 

 each side, the tail valve with 12 slits ; the eaves pale blue and 

 not spongy ; the insertion plates are radially sharply grooved 



