18 PROCEEDINGS OP THE ACADEMY OF 



Anodonta undulata and A. lacustris, Lea, showed no signs of sensitiveness. Unio 

 ■inflalus exhibited but little motion, while numerous specimens of U. radiatus in- 

 variably gave more or less sign when the interruption of light took place. Some 

 individuals were more sensitive than others, and the females exhibited this 

 power much more than the males, often withdrawing, not only their siphons, 

 but their mantle within the valves. 



It is difficult to say with certainty how far their visual organs are developed, 

 as well also as to number and exact position. The fringes of the branchial and 

 and anal siphons are, in the Uniones, formed of small, subconical tentacula. 

 These are larger in the branchial siphon of Unio, while they do not exist at all 

 in the anal opening of Anodonta;. With a good lens the terminal point of the 

 tentacula may be observed to be rounded and furnished with at least the ap- 

 pearance of an eye, and that it will prove to be a true eye, however imperfect, 

 there can be but little doubt. Mr. Lea did not intend to pursue the minute ana- 

 tomy of this organ ; he left it to Dr. Leidy, who had done so much in the histo- 

 logy of the terrestrial Gasteropods, believing that he would be able to make out 

 the complete anatomy of the eye in the U7iio. 



February 17 tJi. 



Vice-President Lea in the Chair. 



Communications for publication in the Proceedings were read, en- 

 titled :— 



1. Notice of a collection of Reptiles made by Dr. Henry A. Ford in 

 the Gaboon country, West Africa, by Edward Hallowell, M. D. 



2. Description of thirteen new species of Uniones from Georgia, by 

 Isaac Lea. 



Which were referred as usual to Committees. 



Dr. Leidy made the following observations on entozoa found in the 

 Naiades. 



He had observed a curious parasite allied to Aspidogaster conchicola, infesting 

 Anodonta fiuviatilis and Anodonta lacustris, within the cleft of the upper bran- 

 chial cavity, adhering to the outer surface of the renal organ and the con- 

 tiguous margin of the foot. The new parasite, for which the name of Cotylaspis 

 insignis was proposed, is from ^ aline to 1 line long, curved funnel shaped, with 

 the base forming an oval ventral disk provided with an outer circle and an inner 

 row of acetabula 29 in number. The animal is provided with distinct eyes, 

 while Aspidogaster, in accordance with its being imprisoned in the pericardium 

 of the Naiades, is blind. 



February 2At7i. 



Vice-President Bridges in the Chair. 



The following communications, on report of the Committees to which 

 they had been referred, were ordered to be published in the Proceed- 

 ings. 



Descriptions of Americau L and Shells. 



BY W. G. BINNEY. 



Helix intercisa. Testa solidissima, luteo-ciuerea, apicc rufa, globoso-conica ; 

 epira brevis, sutura impressa ; anfr. quinque convexiusculi, lineis parallelis, vol- 

 ventibas, yalde demissis, strias incrementales distiactas intercidentibus ; anfractue 



[Feb. 



