1890.] 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 Heloierma is placed beyond tlie 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 HelodermatidcB, 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 VaranidcB or perhaps to Iguanidce. 

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

 XenosauridcB and the Anguidce ; while Gill (56) has created a 

 superfamily for them, ranging it as the Helodermatoidea next above 

 his superfamily the Faranoidea, and the Aniellidts, of his superfamily 

 Anielloidea, immediately preceding them. Bocourt (34) recognizes 

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

 Tracliydermi, Wiegm., several lizards to which it offers 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 Helodenna, but this dental character, of great importance 

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

 Reptiles, as is exemplified by the serrated teeth of Macroscincus 

 cocteei, 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 borneensis, 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 Helodermatidcs 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 HelodermatidcB 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 

 affines 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 HelodermatidcB will not be 

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

 from some of its external characters. 



Proc. Zool. Soc— 1890, No. XII. 12 



[11] 



