NO. 2258 TAENIOID CESTODES OF DOGS AND CATS— HALL. 



13 



Hosts. — Primary: Felis catus {F. domestica) , F. maniculata, F. 

 macrom'a, F. concalor, F. melivora, F. onca, F. mitls^ F. tigrlna^ F. 

 eyr'a, F. sylvestris {Catus sylvestris) .^ Lynx uintd {Lynx tienta)., 

 Miistdla erminea {Putorius erminea). Secondary: Miis musculus^ 

 Epimys rattus alexandrinus {M. rattus alexandrinus, M. tectorum)^ 

 Epimys norvefficus, E. rattus rattus, Micro f us arvalls {Arvicola ar- 

 valis), A. amphibius {A. amphibia), '''' Lenh7mis tei'vestHs,^^ Ondatra 

 zibethica {Fiber zibethicus) , Talpa europaea, Plecotus auritus. 



Location. — In small intestine of primary hosts. In liver of sec- 

 ondary hosts. 



Localities. — Germany, Austria, Italy, France, Enghmd, Denmark, 

 Iceland, Persia, Japan, United States. 



Life history. — Eggs developed by the adult worm in the intestine 

 of the primary host pass out and are ingested by the secondary host 

 in contaminated food or water. In 

 the digestive tract of the second- 

 ary host, the embryo escapes from 

 the shell and makes its way to the 

 liver, where it develops into the 

 larval stage or bladderworm, com- 

 monly known as Gysticercus fascio- 

 laris. This bladderworm is char- 

 acterized by the presence of a very 

 small caudal bladder or vesicle 

 filled with fluid and a very long 

 strobilate connection between this 

 caudal bladder and the head. 

 When the cysticercus is ingested by 

 the primary host, the caudal blad- 

 der digests off and new segments are formed back of the existing 

 strobilate portion, thereby developing into the strobilate tapeworm. 



The record from Lynx uinta in the above list is new. It should 

 be noted that Liilie (1910) states that an examination of Diesing's 

 South American cestodes, on which some of Diesing's records of T. 

 taeniae formis are based, did not disclose a single specimen of this 

 worm. 



TAENIA MACROCYSTIS (Diesing, 1850o) Liihe, 1910. 



Synonym. — Cysticercus Tnacrocystis Diesing, 1850(Z. 



Specific diagnosis. — Taenia: Head 1.25 to 1.6 mm. in diameter. 

 Rostellum from 515 to 690 [jl in diameter and armed with a double 

 crown of 60 to 74 hooks (fig. 7). The large hooks are alternated 

 with the small in the customary manner, but in addition every other 

 large hook is set a little closer to the center of the hook circlet than 

 is the case with the remaining large hooks, with the result that the 

 hook crown is arranged in one circlet of small hooks and two circlets 



Fig. 7.— Taenia macrocystis. Hook circlet 



VIEWED FEOM THE FRONT. X 60. AFTEB 

 Lt)HE, 1910. 



