232 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.40. 



2. The shape of the caudal fin is variable, the young (fetal) speci- 

 mens having the caudal rounded (see plate 11) while in the adults 

 it is truncate. (See plate 10.) 



3. The adult males seem to be proportionally narrower than the 

 females. This difference is not apparent in the young. The males 

 that are referable to the subspecies umbrosa are especially narrow. 

 We have no females of this form. 



4. The difference in color between the young and the adult should 

 be noted. The young have the dark spots very definite in outline 

 while in the adult they are much less distinct and are sometimes 

 formed by a close grouping of small spots about the size of a pin head. 



An interesting life-liistory note on Narcine brasiliensis by Russell J. 

 Coles is published in Bulletin 28, of the American Museum of Natural 

 History, 1910, page 337. We quote the note in full: 



In July, 1909, I first saw this electric ray and captured two specimens which were 

 presented to the laboratory of the Bureau of Fisheries at Beaufort, N. C. They were 

 the first recorded on our Atlantic coast north of Florida. In July, 1910, I captured 

 and preserved eleven specimens at Cape Lookout and know of the capture of more 

 than a dozen others by the native fishermen during the same week; and none were 

 seen either before or after that week. This ray can give a very powerful electric 

 shock. I have been knocked down many times by this shock while experimenting 

 with the fish, yet could make no record of this peculiar form of electricity as it had no 

 effect on my battery-testing ammeter and it would not light a little electric lamp which 

 only required two and a half volts. Probably it might have been recorded by a volt- 

 meter, but I had none with me. 



Several specimens which I found buried in the sand in shallow water with only the 

 eyes and a little of the head and back showing were speared, and others were caught 

 in the haul net. 



Several bare foot native fishermen were knocked down by accidentally stepping on 

 them in shallow water. These rays remain soft and rubber like in a formalin solution 

 which hardens other specimens. 



