629 



much reduced, concavity nearly effaced and visible only on 

 account of the hooks; 100-130 hooks on each sucker with base 

 7 u to 8 fi, prong 3 /i to i u. Neck 90 ;*to 140 /^ by 45 u to 70 ft. 

 One specimen with 20 segments, last segiment 153 /J- long by 195 

 /i broad. Genital pores near anterior corner of segment; cirrus 

 pouch large, extending over halfway across the segment. 

 Type specimens: Collection Rosseter; Collection Stiles. 

 Life history: Cysticercold in Cypris cinera Brady. 

 Hosts: Adults in tame duck (Anas boschas dom.), experi- 

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



Geographical distribution: Canterbury (Kent), England, by 

 Roisseter. 



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

 Royal Microscopical Society stating that he had infected ducks 

 with a cysticercus 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 (1891B., pp. 

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

 Canter'bury for cysticercoids, and noticed that Cypris cinera 

 Brady contained two species of parasites. One was the larval 

 form of Taenia coronula (=Dieranotaenia coronula); a less 

 commoh 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 conti'actions, 

 but when fully developed to a point where it can be trans- 

 mitted to vertebrates it remains quiescent; rostellum invag- 

 inated, bearing a crown of 10 hooks 32 fi 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 /i long. 



A large number of crustaceans were fed to a duck daily from 

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

 number of tapeworms, which showed the same characters as 

 the cysticercold, were found in the upper portion of the small 

 intestine. The largest was 1.27mni 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 (1S81B, pp. 420-42S, figs. 1-2) examined some of 

 Rosseters material and recogrnized that this form was not 

 identical with T. lanceolata. He romparpd it with all the 



