256 



PROCEEDINGS OF THE ACADEMY OF 



: [May, 



May 27. 

 Mr. Arthur Erwin Broavx, Vice-President, in the Chair. 

 Seventeen per.sons present. 



Papers under the following titles were presented for publication : 

 " The ]\Iollusca of the Mount Mitchell Region," by Henry A. 

 Pilsbry and Bryant Walker. 



" Synopsis of the American Martens," by Samuel N. Rhoads. 



The deaths of Ferdinand J. Dreer, a member, on the 25th inst. , 

 and of Henri Filhol, a correspondent, were announced. 



A Peculiar Heliozoan. — Mr. How'Ard Crawley remarked that 

 the heliozoan here figured was found on August 8, 1900, in water 

 taken from a stagnant, spring-fed pool, near ^yyncote, Pa. 



The animal was almost perfectly spherical and showed no altera- 

 tion in form while under observation. Its diameter Avas about 90 

 microns. Around the central part of the body there was an irregu- 

 lar whorl of large alveoli, and, in addition, a number of elements 

 which may have been either small alveoli or large colorless granules. 

 There was no distinction between cortex and medulla, the whorl of 

 alveoli lying in a cytoplasmic matrix, uniform throughout. This 

 matrix was colorless and granular, and closely resembled the 

 endosarc of an Amreba. Within it was a diatom which still showed 

 a little colored substance, and a number of more or less completely 

 digested plant spores. 



Occupying a slightly excentric 

 position was a large vesicle, 

 having the form of an ellipsoid. 

 The contents of this vesicle were 

 jDcrfectly homogeneous under a 

 magnification of 370 diameters, 

 and of a very pale-green color. 

 It was probably a food-ball. 



From the surface of the ani- 

 mal arose a number of minute 

 protoplasmic processes. These 

 occurred in clusters, which were 

 ^' ^^_^ '"^ - separated from each other by 



I 'f approximately the same distance 



as that which ordinarily sepa- 

 rates the typical heliozoan pseudopodia. It was further to be 

 observed that at the points from which these clusters arose there 

 were breaks iu the continuity of the animal's contour, such as 

 those which are seen at the point where a pseudopodium arises. 

 Two conditions which these clusters presented are illustrated iu 



