ON A NEW REPTILIAN CESTODE. Ill 



then this species, for which the specific name tidsivelli is 

 suggested in recognition of the scientific interest shown 

 by the Directer of the Bureau of Microbiology, Dr. F. 

 Tidswell, must come under this genus. 



Prof. S. v. Ratz in a preliminary communication 1 dealing 

 with three new cestodes from Varanus sp., from New Guinea 

 described two species of Ichthyotaenia (I. biroi and I. 

 saccifera) and a Taenia (T. mychocephala). Unfortunately 

 the fuller descriptions were published in journals 2 which 

 are not available in this State, and consequently I can only 

 compare my specimens with Ratz's unfigured account. 

 However, his descriptions are fairly full and leave very 

 little doubt in my mind that I. biroi, I. saccifera, and I. 

 tidsivelli are very closely related. The scolex is very 

 similar in all three, all possessing the delicate covering 

 of spines which do not deserve the name " hooks " given 

 to them by Ratz. The worms are unarmed, since I do not 

 consider a mere raising of the cuticle in the manner 

 described, to be comparable to an armature. Ratz, how- 

 ever, considers the scolex to be armed in his species. I. 

 biroi possesses a narrower scolex and more projecting 

 suckers than I. tidsivelli. The depression mentioned as 

 being present at the apex of the rostellum in the former is 

 absent in the latter. No measurements of the scolex of 

 I. saccifera are given. A long neck is present in the first 

 two but practically absent in the last species. The seg- 

 mentation in our tapeworm is similar to that described for 

 I. biroi. The genital openings, however, are differently 

 situated. In I. tidswelli, they are not borne on a papilla, 

 and are situated in the posterior half of the mature segments 

 whilst in I. biroi and I. saccifera they open in front of the 



1 Centrb. f. Bact. I, Orig. xxvin, 1900, p. 657. 



2 (a) Arch. d. Parasitol., iv, 1901, p. 329. (6) Compt. Kend, Soc. Biol., 

 lii, 1900, p. 980. (c) Kiilonlenyom at a Potfuzetek, lvii, 1900, p. 22. 



