COPEIA 75 



Accompanying tin's abnormality in coloration 

 there were irregularities in scale pattern, espe- 

 cially on the head, which suggests that whatever 

 cause operated to prevent the formation of black 

 pigment also may have had some effect on scale 

 formation. Several of the head scales are of quite 

 different shape than those found on a normal 

 specimen, and some show suggestions of divisions 

 which were not completed. There are four post- 

 oculars, where but three normally occur. The 

 body scales, save for the interpolation of an 

 incomplete gastrotege which extends but half way 

 across the body, are quite typical and numerically 

 are within the limits given by Cope. (The Crocodil- 

 ians, Lizards and Snakes of North America, Ann. 

 Rept. Smithsonian Inst., for 1898, 1900, pp. 877, 

 878), viz: Dorsal scale rows, 31 (Cope, 29-33) ; gas- 

 trosteges, 223V2 (204-245); urosteges, 64 (56-72). 



This snake was kept in captivity for more than 

 a year, confined in a glass terrarium with a screened 

 top. It was provided with water and at intervals 

 small white mice were fed to it; one of these bit the 

 snake on the head and produced a "scalp" wound. 

 One morning after the animal had been in captivity 

 for about four months the skin on the preorbital por- 

 tion of its head was seen to be free from the scales 

 beneath. Some straw was placed in the terrarium and 

 within a few minutes the snake was working rapidly 

 back and forth through the straw, freeing itself from 

 the old skin. At the place where its body was just 

 being freed from the skin, violent muscular expan- 

 sions and contractions were being executed. The 

 surface of the snake's body and the outside, originally 

 the inside, of the sluffed skin were noticeably moist 

 as a result of the secretion which had been poured 

 out to assist in moulting. For several weeks previous 

 to moulting the snake had been quite sluggish, re- 

 maining coiled in one corner of the terrarium and 

 refusing food. During this time its eye became grad- 



