112 T. H. JOHNSTON. 



middle of the pore-bearing edge, on a small papilla. The 

 alternation is similar in each. The whole of the male and 

 female genitalia with their accessory organs, do not show 

 any important differences in the three species, except that 

 the vagina opens in front of the cirrus in I. biroi, whilst it 

 may or may not do so in I. tidswelli and I. saccifera. Ratz 

 states that the vitellaria occupy a wide zone in I. biroi, 

 whereas they form a very narrow and inconspicuous series 

 in our species. The cirrus sac is pyriform in I. tidswelli, 

 roundish in I. saccifera, and cylindrical but somewhat 

 swollen on its inner half in I. biroi. The ovary is branched 

 in I. tidswelli and I. biroi but not in J. saccifera. The 

 uterus in the last species is widest immediately in front of 

 the ovary, whilst in the other two, it has a fairly regular 

 lumen and forms egg-pouches. It will thus be seen that 

 the cestode from Varanus varius approaches I. biroi in 

 most of its characters. 



The description of Taenia mychocephala is too short to 

 allow of its systematic position being assigned with cer- 

 tainty. 



In 1903 Dr. von Linstow 1 described a cestode from a 

 Ceylon Monitor, Varanus (Hydrosaurus) salvator, under 

 the name of Acanthotaenia shipleyi. Having only a single 

 mounted specimen, he was unable to section it, and conse- 

 quently the description is incomplete. However, the 

 parasite possessed certain well marked characters which 

 led him to make it the type of a new genus, Acanthotaenia, 

 with the following characters; the cuticle of the scolex 

 and of the anterior part of the body densely covered with 

 fine bristles; the rostellum unarmed; genital openings 

 lateral and alternating irregularly; testes about fifty 

 in each segment; segmentation hardly distinguishable 

 externally. 



1 (a) Centrb. f . Bach, I, Orig. xxxiii, 1903, p. 532 ; (6) Spolia Zeylanica, 

 I, 3, 1903, p. 51. 



