PROCEEDINGS 



OF THE 



CALIFORNIA ACADEMY OF SCIENCES 



Fourth Series 



Vol. IX, No. 12, pp. 313-329 December 23, 1919 



XII 



MECHANISM IN THE PRODUCTION OF THE 



THROAT-FAN IN THE FLORIDA CHAMELEON, 



ANOLIS CAROLINENSIS^ 



BY CHAS. E. VON GELDERN 



I 



The production of the throat-fan in the Florida Chameleon 

 (Anolis carolmensis) , is, aside from the remarkable cutaneous 

 color changes, one of the most striking features of this 

 lacertilian. 



The distended throat-fan, dewlap or gular pouch, which is 

 best developed in the males, is a thin fold of skin attached 

 along the mid-ventral line of the throat. It is somewhat 

 semicircular in outline and extends from the intersection of 

 the mid-ventral line and a line drawn at right angles passing 

 through the eyes, to a variable distance on the chest. 



The color of the distended fan varies from a delicate pink 

 to a bright vermilion and, on closer observation, is spotted 

 with scattered white scales. 



When the fan is retracted, the skin on the throat is loose 

 and arranged in longitudinal folds. It is white in appearance 

 with minute longitudinal red, linear markings. The scales 

 are prominent and appear as small, laterally depressed cones. 



' The dissection of Anolis was made in the department of Anatomy of Tulane Uni- 

 versity. The comparative work was done in the department of Zoology at Stanford 

 University. I am indebted to Professor J. O. Snyder for the material used in 

 dissection. 



December 23, 1919 



