6 



DR. F. E. BEDDAED ON 



It must be remembei^ed that when Dr. Shipley desci'ibed Falaia 

 varani the genus Ichthyotcenia had not actually been described 

 from Varanus, since Ratz's memoirs appeared contemporaneously 

 with that of Dr. Shipley. Dr. Shipley himself thought that 

 Palaia came nearest to Oochoristica, a genus which also occurs in 

 reptiles. He did not consider Panceria^ to which I shall refer 

 immediately in this connection. 



The reasons which lead me to regard Palaia varani as a species 

 of Ichthyotcenia are largely negative, but there are also one or 

 two positive facts. Firstlj^, the only Ttenioid parasites of Varanus 

 are Ichthyotcenia and Pancerinco, and as to the former it is now 

 known that four species of Varanus harbour different species of 

 Ichthyotcenia. This is not obviously conclusive against the 

 occurrence of another genus ; but it may be borne in mind 

 as something of an argument. The general structure of Palccicc 

 is not in the least opposed to its inclusion in the genus Ichthyo- 

 tcenia. It is of course true that the same characters would fit 

 other genera, and unfortunately the reproductive sj^stem could 

 not be described in any detail. The author gives a figure of a 

 transverse section of the worm, whence it would appear that the 

 transverse muscular layer lies in the medullary parenchyma, as 

 has been described by Schwarz in his memoir referred to on this 

 genus Ichihyotasnia. The most important positive reason for the 

 inclusion of Palaia varani in the genus Ichthyotcenia is in the 

 chai'acter of the eggs, which are particularly described and figured 

 as lying in clumps, the individual eggs being adherent. This is 

 highly char-acteristic of the reptilian members of the genus, and 

 I have something in the present paper to say upon the matter. 



The genus Pancerina (originally described under the pre- 

 occupied name of Panceria) occurs in Varanus arenarius, whence 

 it has been described by Sonsino * and Stossich t, more fully 

 by the former of these two authorities. Pancerina is placed by 

 systematists t in the neighbourhood of Oochoristica, to Avhich 

 Dr. Shipley thought that Palaia was allied. The double repro- 

 ductive organs in each proglottid prevent any confusion between 

 this genus and Ichthyotcenia. Nevertheless there do not appear 

 to me to be any positive facts which forbid the near relationship 

 of Pancerina and Ichthyotcenia, there.being no definite statement 

 by Sonsino as to the vitelline gland. 



In two specimens of Varamis niloticus a series of small tape- 

 worms was found which clearly belong to this genus Ichthyotcenia. 

 I am inclined to think that the wornas from one specimen of this 

 Varanus Sire difi'erentfrom those found in another specimen of the 

 lizard. But inasmuch as the worms of one series were not mature, 

 I am not able to speak Avith certainty as to some necessary specific 

 characters. Moreover, I had the opportunity of examining one 

 series in the living condition, and am not therefore able to report 



* Monit. Zool. Ital. vi. 1895, pp. 121 & 189. 



t Boll. Soc. Adr. Trieste, xvi. 1895, p. 42. Described as Tcenia varani. 



X JE. g., Ransom, Bull. U.S. Nat. Mus. no. 69, 1909. 



