1879.] NATURAL SCIENCES OF PHILADELPHIA. 11 



generally of much lighter color, and more robust character than 

 the males. In both sexes the body is most attenuated anteriorly, 

 but in the female the body is nearly as thick at the posterior ex- 

 tremity as it is at the middle. Some of the smaller males are pale 

 brownish-white, but most of them, from the smallest to the largest, 

 are of various shades of brown to chocolate-brown. The females 

 are pale brownish to darker brownish. In both sexes the head 

 forms a convex, whitish eminence, encircled by a narrow black 

 ring, from which a hand of brown extends dorsal ly and ventrally 

 along the body. The posterior end of the body is likewise of 

 darker color than the part just in advance. 



The tail of the male makes a spiral turn inwardly, and is furcate. 

 The forks are short, curved, slightly divergent, blunt conical pro- 

 cesses. Just in advance of their conjunction internally, there 

 exists an inverted crescentic fold of browner color than the con- 

 tiguous parts, and immediately in advance is the genital pore. 

 The interval of the caudal forks is smooth, or free from papillae. 



The tail of the female appears truncated; is bluntly rounded, 

 feebly clavate, or slightly thicker than just in advance, and nearly 

 as thick as the middle of the body. It presents a terminal pore, 

 marked by a brown spot, and encircled with a brown ring. 



Under a moderate magnifying power, the brown integument is 

 minutely mottled with whitish spots, and it exhibits fine longitu- 

 dinal and diagonal striation. In sunlight it is beautifully irides- 

 cent as in the earth-worm. 



The worms are still quite lively. When disentangled and left 

 alone they soon become again knotted together in a compact 

 rounded mass as at present, with the heads divergent, and writhing 

 so as to remind one of the head of the fabled Medusa. 



Prof. Leidy then directed attention to several other specimens 

 which had been sent to him for information. One of these is a 

 bunch of tapeworms, 15 individuals of Taenia diminuta, from the 

 intestine of a rat. The other is the liver of a rat, with a multitude 

 of cysts, the size of large peas, containing Cyxticercus fasciolaris. 

 In a letter, accompanying the specimens, Dr. John R. Hewett 

 states, that last spring he had examined about 500 rats (Mm de- 

 cumanus), in Carroll Co., Mo., and only in half a dozen instances 

 did he find the liver free from the parasite. 



Messrs. Geo. A Binder, Jacob Binder, Charles Henry Hart, and 

 H. Dumont Wagner were elected members. 



The following papers were ordered to be printed: 



