]899.] 'l.A>-THANOTUS BOKXEE>SIS, 597 



the absence of a postfronto-sqnamosal arch, the slender clavicles, 

 the absence of transverse processes to the interclavicle, together 

 with the character of the tongue, settled the question beyond 

 dispute. The sciagraph further revealed the fusion of the pre- 

 maxillaries and of the parietals, which are devoid of a pineal 

 foramen, the distinctness of the nasals and of the frontals, the 

 presence of a small supratemporal, and the absence of a squamosal. 

 The vertebrae numbered 103: 8 cervical, 26 dorsal, 1 lumbar, 

 2 sacral, 66 caudal. The first three dorsal vertebrfe bore sternal 

 ribs, as in Varaniis, Belodei-ma having 4 sternal ribs. The 

 phalanges, in both mauus and pes, numbered 2, 3, 4, 4, 3 ; there 

 was thus one phalanx less in the fourth digit and in the fifth toe 

 than in Heloderma and Yaranus. 



The resemblance of the open mouth of Lanthanotus, as shown 

 in the accompanyiug figure, to that of Heloderma was extremely 



Open mouth of Lcmthanotus borueensis. 



striking. The teeth were similar in both genera, but they showed 

 no traces of grooves in Lanthamtus. There were 7 teeth in the 

 prgemaxillary bone, 12 in each maxillary, 12 in each raoius of the 

 mandible. The palate was toothed as in Heloderma : one tooth 

 on the palatine bone, four on the pterygoid. The tubercles on the 

 head and body were devoid of ossifications. The lower eyelid was 

 entirely occupied by a single semitransparent shield. 



The specimeu in the Sarawak Museum, a male, obtained in the 

 Eejang Eiver District in 1891 by the Hon. C. A. Bampfylde, was 

 a little smaller than the type in the Vienna Museum. It had a 

 total length of 310 millim., in which the head entered for 22 and 

 the tail for 160 ; fore limb 30, hind limb 38. 



Proc. Zool. Soc— 1899, No. XXXIX. 39 



