AVIAN CESTODES. 601 



is a parasite of anotliei" subspecies of tStruthio, viz. ;S'. moh/bdo- 

 phanes. While the general dimensions and the relative size of 

 the scolex seem to be much the same in v. Linstow's species and 

 in my own, there are sevei^al salient features in which they 

 disagree markedly. The scolex of v. Linstow's worm has no 

 rostellum, in the species ex;imined by myself the rostellum is 

 strong : v. Linstow's species has no calcareous bodies in the 

 scolex, while my species is peculiarly well provided with these 

 bodies : whatever may be the interpretation of the "ovaries" of 

 v. Linstow in the posterior segments of his species, whether they 

 are really a divided uterus or paruterine bodies, that Cestode 

 clearly differs from mine where the embryos are scattered each 

 one in a cavity of its own : finally, if v. Linstow's representation 

 of the cirrus-sac and the vagina- opening quite sepai'ately prove 

 correct, there is here a great difference from my species, where 

 the relations between these ducts is quite normal. These facts 

 are, as I think, sufficient to show that there can be no identity 

 between the two Cestodes of Struthio masaicus and Struthio 

 molyhdojjhanes *. 



On the other hand, an exact comparison of my species with 

 that termed Tcenia stnithionis by Parona is more difficult. If we 

 can trust as differential characters the diameter of the proglottids 

 and the size of the scolex, then the two forms are different. 

 There are no other data that seeni to permit of a more definite 

 expression of opinion. 



* I have snp;gcste<l (P. Z. S. 1015, p. 430) tliflt v. Linstow's spocics may bo 

 actiinn.y rcferablo to the goiins Chapmania, 



