T^ENIA MEDIOCANELLATA. 135 



Rostellum nullum. Collum perbreve, sed distinctius, quam in 

 T. soliura. Articuli posteriores latissimi, ad 17 millim. lat. et ad 

 9 14 millim. long, crassi, poris genitalibus irregulariter alter- 

 nantibus. Proglottides permagrwe et pervivaces, scepissime sponte 

 et sine faecibus humanis ex ano demissce, cegrotumque valde 

 perturbantes ; in maxima sua extensions. 25 30 millim. long, et 

 ad 7 millim. lat. 



Uterus permultos ramos (ex utroque latere usque ad 30), in 

 margitie libero clav&formes , non amplius dendritice, ad summum 

 bifurcatim divisos, inter se paralltlos. 



Ovula magis ovalia, laeviora et clariora, quam in Tsenia solium, 

 ad 0-036 millim. longa et 0-028 33 lata ; testa crassd } uti in 

 T. solium. Embryones 0'028 32 mill, longi, 0*023 26 lati. 



Scolex quiescens ignotus. Fortasse in Sue aut Bove, fortasse in 

 animal, inferior, ordinum. 



The epidermis of this animal is thick and very distinct, of soft 

 structure, consisting of delicate lines crossing each other, and 

 without calcareous corpuscles. The epidermis is followed by a 

 layer of longitudinal muscles, which run through the whole body 

 of the animal, and form bundles of 0-245'" = 0-545 millim. 

 These, as well as the next layer of transverse muscles, contain 

 the calcareous corpuscles imbedded in them. The fasciculi into 

 which the layers can be split are about 0-070'" = 0-158 millim. 

 in diameter; they pass nearly to the upper and lower margins of 

 the segments, but always disappear at a short distance from these 

 margins. 



The size of the sucking discs, which are quite black, gives the 

 head of this T&nia a considerable bulk, and it is easy to under- 

 stand how the older authors spoke of four large black eyes in 

 this animal. I have seen, in all, seven heads of this Ttenia ; two 

 of these are in Paris, and were given with my prize essay; one 

 is in the possession of Van Beneden ; I possess two myself; 

 I have seen one with M. Gurlt, and the other was left with the 

 patient. From their size, they were all of different ages ; the 

 segments were of different sizes, but the heads of all were in the 

 same state, and only that expelled in Travemiinde was paler, 

 because more sparingly furnished with pigment. 



The very simple vascular net-work consists of a transverse branch, 

 running through the free space between the four sucking discs ; 

 from this a branch runs to and around the sucking discs, until 

 the four well-known longitudinal vessels are developed from them 



