629 



much leduced, concavity nearly elTaced and visible only on 

 accounl of the hooks; 100-130 hooks on oach sucker wltli bas.> 

 7 u to S n, prong 3 /» to 4 u. Neck 90 /'to 140 // by 4J u to 70 li. 

 One specimen with 20 segmento, last segment 163 /* long by ISS 

 II broad. Genital pores near anterior corner of segment; cirrus 

 pouch large, extending over halfway across the segment. 

 Tyi)e specimens: Collection Rosseter; Collection Stiles. 

 Life history: Cystlcercold In Cyprls cinera Brady. 

 Ilo.sts: Adults In tame duck (Anas boschaa dom.), experi- 

 mentally by Rosseter; Bengal duck (Anas sp ?) by Rosseter. 



Geographical distribution: Canterbury (Kent), Kngland, by 

 Rosseter. 



Rosseter (1891A., p. 438) presented a communication to the 

 Royal Microscopical Society stating that he had Infected ducks 

 with a cystloercus and thus raised Taenia lanceolata. There 

 were from 180-200 minute hooks on the head. A fuller account 

 Is given In his second paper. In which Rosseter (1891 B., pp. 

 224-228) states that he examined the Cyprldae of a pond near 

 Canterbury for cystlcercolds, and noticed that Cyprls cinera 

 Brady contained two species of parasites. One was the larval 

 form of Taenia coronula (^Dleranotaenla coronula); a less 

 common form occurred in about 2 per cent, of those examined. 

 The latter form Is oval. Invaginated anteriorly and provided 

 with a long caudal appendage; cyst Is not fenestrated. While 

 developing. Its substance submits to active contractions, 

 but when fully develaped to a point where It can be trans- 

 mitted to vertebrates It remains quiescent; ro.'^tellum Invag- 

 inated, bearing a crown of 10 hooks 32 /i long, of which three- 

 fifths are occupied by the dorsal root; ventral 'root rather trun- 

 cate; prong short and slightly curved. Suckers oval, armed 

 with about 132 booklets, arranged symmetrically around the 

 suckers; the hooks are very delicate, about 5 fi long. 



A large numlber of crustaceans were fed to a duck dally from 

 February 19 to March 21. Upon killing the duck a considerable 

 number of tapeworms, which showed the same characters as 

 the cystlcercold, were found In the upper portion of the small 

 Intestine. The largest was 1.27mm long; the greater number of 

 specimens possessed 17 segments. Male organs were well de- 

 veloped, but the female organs were not visible. Rosseter be- 

 lieved that the adult parasite which he had thus developed was 

 Taenia lanceolata Goeze. 



Blanchard (ISSIB, pp. 420-428, figs, 1-2) examined some of 

 Rosseter's material and recognized that this form was not 

 identical with T. lanceolata. lie compared It with all the 



