189U.] HELODERMA SUSPECTUM. 157 



Experiments made by a number of competent investigators during 

 the past few years have satisfactorily demonstrated the fact to my 

 mind that the venomous or non-venomous character of the bite of 

 the Heloderma is placed beyond the peradventure of cavil, for there 

 can be no doubt now but that its bite is soon fatal, at least to the 

 smaller kinds of animals. Whether it has ever proved fatal in the 

 case of man I believe still remains an open question, although I 

 am inclined to believe that that, too, will sooner or later be substan- 

 tiated. 



With respect to the affinities of the Heloclermatidce, authors have 



entertained a variety of opinions; and, so far as I can ascertain, herpe- 



tologists are still considerably in doubt as to the position of these 



reptiles in the system, and which group constitute their nearest kin. 



The opinion has been very generally held that the Heloderms are 



more or less nearly related to the Varanidce or perhaps to Iguaiiidm. 



Cope, in his recent work (61), places them as a family between the 



Xenosauridce and the Anyuidce ; while Gill (56) has created a 



superfamily for them, ranging it as the Helodermatoidea next above 



his superfamily the Faranoidea, and the Aniellidce, of his superfamily 



Anielloidea, immediately preceding them. Bocourt (34) recognizes 



the family Helodermidce, and " associates with it under the family 



Trachydermi, Wiegui., several lizards to which it oifers considerable 



zoological affinities ; they differ from it in having smooth ungrooved 



teeth. Such a difference might at first seem to militate against their 



union with Heloderma, hut this dental character, of great importance 



in the higher Vertebrata, has only a secondary importance among the 



lleptiles, as is exemplified by the serrated teeth of Macroscmcus 



coctcei, D. & B." (Zool. Rec. 1878). A few years ago, Steindachner 



(35) described a new reptile from Borneo to which he gave the name 



of Lanthanotus bonieensis, and which he claimed was related to the 



Heloderms. We are, however, of the opinion that that fact is by 



no means a settled one. Nevertheless, Boulenger has placed the 



genus Lanthanotus after the family Helodennatidce in the Catalogue 



of Reptiles in the British Museum (55), but remarks that " Whether 



the following genus is to be placed here, or constitutes a distinct 



allied family {Lanthanotidce, Steindachner), must remain doubtful 



until its anatomical characters are known. Its dentition was 



originally stated to be the same as in Heloderma, but this has been 



subsequently corrected by Steindachner." In the Catalogue we 



have cited, Boulenger has characterized the Helodermatidce for us 



in a masterly manner, and in the same place he presents us with the 



characters of Lanthanotus, so far as they are at present known 



from Steindachner's description. It is evident, then, that a complete 



account of the anatomy of this Bornean reptile, one of the supposed 



affiues of Heloderma, is very much to be desired ; I am inclined to 



think, however, at present, that when its morphology comes to be 



fully known, its affinity with the Helodermatidce will not be 



found to be a near one by any manner of means, judging, as I do, 



from some of its external characters. 



Troc. Zool. Soc— 1890, No. XII. 12 



