L. Stieda on the Taenia*;. 105 



accurate statements as to the length and size of this Taenia, as 

 the examples of it which I have seen were never quite perfect, 

 and, especially, never possessed maturely developed proglottides. 

 I mention only that this Tapeworm exactly resembles the T. 

 omphalodes in regard to its head and upper part, although it is 

 of rather smaller dimensions; in the lower part, however, it 

 differs in that the joints, as they grow narrower, become con- 

 siderably elongated, so that the last joints are three times as 

 long as broad, and appear somewhat compressed laterally. I 

 regard this Tapeworm as identical with the Taenia pusilla, Goeze, 

 which, indeed, has hitherto only been mentioned as occurring in 

 the common mice and rats, but the description of which suits 

 very well with the present Tapeworm. 



In the small intestine of the Shrew (Sorex araneus) I have 

 met with two Tapeworms distinctly differing from each other 

 both in size and in the form of the hooks, which, however, do 

 not agree with the characters given by Dujardin* of some Taeniae 

 found by him in the Shrews. I regard them, therefore, as 

 hitherto unknown forms. 



One of these two Taenia, which occurs very frequentl}*, num- 

 bering from ten to twenty in each Shrew, and which I will de- 

 nominate T. uncinata, is 10-15 mill, in length. The head is 

 0*280 mill, in breadth, has four sucking-disks 0*050 mill, in 

 diameter, and a short proboscis, which has a simple circlet con- 

 sisting of fourteen to eighteen hooks. The head passes imme- 

 diately into the neck, which is but little narrower, and exhibits 

 no segmentation. The number of recognizable joints is about 

 120. The joints immediately following the neck are 0*182 mill, 

 in breadth ; and as they advance they increase both in length 

 and breadth, so that the last joints are about 0*560 mill, broad 

 and 0*210 mill. long. The sexual orifices all occur upon one 

 side of the worm, each in the middle of the joint. The hooks 

 have a very characteristic form ; they are very strongly curved, 

 and have a rather fine point. The extreme point of the hook is 

 distant from the extremity of the root-process 00175 mill., and 

 from that of the dental process only 0*0035 mill. ; the two pro- 

 cesses are 00140 mill, apart. 



The various stages of development of the sexual organs as 

 presented in the different joints are not so easy to observe in 

 this Tapeworm as in T. omphalodes. It appears only that in 

 this case also the development commences especially at three 

 points in each joint. One of these points is at the upper margin 

 of each joint, where the cirrus-pouch and vagina are formed, 

 whilst the germ-preparing organs are produced from two aggre- 

 gations of cells situated in the middle of the joint. 

 * Hist. Nat. des Helminthes, p. 562. 



Ann. fy Mag. N. Hist. Ser. 3. Vol. xi. 8 



