253 



which enter into its composition. It is deposited here and there, 

 in spots, of various shades of brown, throughout the skin. 



2. The splendid, changeable colors of the surface are due, 

 not to the pigment spots alone, but to the intervening tissue ; 

 and the surface color over the pigment spots is subject to the 

 same variations. These facts may be tested by placing a small 

 portion of the skin on ^plate of glass, and introducing a little 

 water under it, the evaporation of which, by changing the sur- 

 face conditions, generally produces a variety of colors. 



3. The varying hues of the animal are due to the contraction 

 of the muscular fibrillae of the dermis, which changes the sur- 

 face of the skin ; and not, as Mr. Owen has thought, to the con- 

 junction and disjunction of two layers of pigment placed one 

 above the other. By the action of these fibrillse, the most varied 

 shades of surface can be rapidly produced. 



Prof. Wyman stated, in confirmation of these views, that 

 he had noticed large patches of color on the Squid, which 

 at times entirely disappear. This would not be the case if 

 this color were due to pigment. 



Mr. Girard remarked, that in the embryo Squid, before 

 it escapes from the e^2^, he had seen the same changes of 

 color as in the adult. 



Dr. Gould, in behalf of the Committee on Mollusca, to 

 whom had been referred the paper of Mr. T. Prime, on the 

 genus Pisidium, reported in favor of its publication in the 

 Society's Journal. 



Dr. Burnett presented a Collection of Reptiles from the 

 Southern States, of the following species. 



Anolius Carolinensis, Tropidolepis undiilatiis, Ameiva sex- 

 lineata, Scmcus quinque-lineatus, Scincus fasciatus, OpJiisaurus 

 ventralis, Trigonocephalus contortrix, Trigonocephalus piscivo- 

 rus, Coluier constrictor^ Coluber guttatus, Coluber punctatus, 

 Coronella getula, Brachyorrhos amoenus, Rhinostoma coccineum, 

 PsammopMs Jlagelliformis, Heterodon siinus, Heterodon 7iiger, 

 Heterodon platirliinos^ Hylodes gryllus, Engystoma Caroli- 

 nense. 



