TYPES OF SPECIES OF CESTODA KREFFT. 33 



sink into synonymy. The parasite is very poorly preserved and 

 does not allow of a satisfactory account of its structure being 

 given. 



The known geographical range of F. fascioldris, Pall., is now 

 greatly widened by the inclusion of two Australian hosts, Anas 

 superciliosa. Gmel., and Nettion castaneum, Eyton. 



TiENIA CYLINDRICA, Krefft. 



(Plate vi.) 



Krefft's specimens were taken from the intestine of a Black 

 Duck (Anas superciliosa, Gmel.) and are very indifferently 

 preserved. However, enough of the anatomy was made out, to 

 allow of my recognising that they were specifically identical with 

 a few parasites which I collected along with //. collaris, Batsch, 

 (Titnia bairdii, Krefft), from A. si^erciliosa, shot near Sydney 

 in the latter part of 1910. An examination of Krefft's species 

 shows it to be a Hymenolepis and to be synonymous with II. 

 megalops, Nitzsch. In view of the fact that Ransom 73 has 

 carefully described and figured the anatomy of H. mega/ops, only 

 a short account, more or less confirmatory in nature, need be given 

 here. This author appears to have been the only recent writer 

 who has had an opportunity of studying the species under 

 review. Stiles 74 , in 1896, gave a summary of former accounts 

 and added a few figures of the scolex. 



Since Krefft's specimens are strongly contracted, the following 

 account has been based mainly on my own forms. Most of the 

 tapeworms measure about 16 mm., one of them being a fragment 

 which contains six-hooked embryos. The breadth is fairly uniform, 

 measuring about 06 mm. The almost spherical scolex (PI. vi., 

 fig. 1) is relatively very large and prominent, its breadth and 

 thickness being IT mm. The deep, powerful suckers have a 

 diameter of 038 mm. and are directed antero-laterally. Situated 

 on the apex of the head is the opening leading into the rostellar 

 cavity. Segmentation begins immediately behind the scolex, the 

 width in this region being - 55 mm., gradually increasing to 06 

 mm., this latter breadth being maintained almost to the end of 

 the worm. The final segments in some of the specimens, are 

 slightly narrower and longer than those further forward, and, 



" Ransom— Trans. Amer. Micro. Soc, xxiii., 1901 (1902), pp. 158-167. 

 *± Stiles-Bull. Bur. Anim. Ind., Dept. Agr. U.S.A., 12, 1896, p. 59. 



2a 



