1890.] NATURAL SCIENCES OF PHILADELPHIA. 149 



tive plenty on the coral and continental islands of the Caribbean 

 group is due to the absence of carbonate of lime in the former and 

 its presence in the latter. 



Hemarks on the exuviae of snakes. — Dr. Benjamin Sharp further 

 spoke on the exuviae of two snakes, Avhich were shed in the labora- 

 tory of the Academy two days previously. These snakes, Eutameia 

 sirtalis, B. & G., had been presented to the Academy on the 19th 

 of March, 1890, and had been captured the day before in New 

 Jersey. The whole process of shedding the skin had been observed. 

 One of the snakes was in the water when first seen, and coming out 

 upon the sod it shrugged and shook itself for a moment ; then getting 

 between the glass of the vivarium and the box containing the earth, 

 the skin parted at the jaws and the animal crawled out leaving the 

 exuvia. The cerebral portion being fixed, the animal passed through 

 the opening, so that the discarded skin, as is always the case, was 

 turned wrong side out. One of the specimens was interesting as it 

 was entirely perfect, without the slightest rent and not a scale missing. 

 The other was perfect, but there was a considerable rent on 

 each side of the jaw. The operation took less than one -minute. 

 The snake was startled about the middle of the process. It 

 crawled away from the exuvia very rapidly. 



April 22. 

 ]\Ir. Thomas Meehan, Vice-President, in the chair. 

 Twenty-three persons present. 

 The following were presented for jiublication : — 

 " New East Indian Land Shells." By H. A. Pilsbry. 

 " Description of a new species of Helix." By John Ford. 



April 29. 

 The President, Dr. Leidy, in the chair. 

 Twenty-six persons present. 

 The folloAving were elected members : — 

 Abraham Barker, William K. Shryock and Walter Conrad. 

 The following was ordered to be printed : — 



