39 



angle. They are never arborescently divided, nor 

 furcated at the ends, with the exception of the fore- 

 most and the hindmost in each joint, which run, the 

 former forwards, tlie latter backwards ; both being 

 forked and crooked. The eggs, which are extremely 

 plenty in these joints, and which show the configura- 

 tion of the uterus in a yellowish tint to the naked 

 eye, are 0-033 mil. long and 0-030 mil. broad. They 

 are protected, first, by an outside shell (Chorion), 

 which is 0*003 mil. thick, dark in its outside 

 layers, transparent, yellowish inwards ; then follows 

 a second shell (yolk membrane), 0-0006 mil. thick, 

 entirely transparent. In the cavity of the egg lies 

 the embryo, occupying about two-thirds of it, and 

 measuring only 0-016 mil. We saw other eggs un- 

 ripe, and with one egg-shell only, but very rarely." 



The second on the list, the Tsenia mediocanellata 

 (PI. I. fig. 7), was first described, as separate from 

 Taenia solium, by Kiichenmeister, who in all saw 

 seven heads. The body of this species is broader 

 than that of the Taenia solium: the epidermis is 

 thick, very distinct, soft, and without calcareous cor- 

 puscles. Beneath this is a layer of longitudinal 

 muscles, running the whole length of the body, which 

 form bundles of 0-545 mil. Then, below, follows a 

 layer of transverse muscles, in which, as well as in 

 the layer before it, are found calcareous corpuscles. 

 The head is larger than in the Tsenia solium, as are 

 also the sucking discs, which are four in number, 

 and of a black color (PL I. fig. 7, a). In this species, 

 the rostellum and circlet of hooks are entirely want- 



