98 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.39. 



ries; four lower labials, first very small, second and third excessively 

 elongate, together nearly as long as five supralabials ; a large unpaired 

 postmental followed by three pairs of large submandibulars, the two 

 anterior pairs of which are in contact on the middle line ; ear-opening 

 oval, slightly smaller than eye-opening; 32 scales around the middle 

 of the body; nine dorsals in the shielded part of the head; dorsals and 

 laterals strongly keeled and on the posterior half of the body strongly 

 mucronate, the keels of the dorsals forming six straight lines on the 

 back, the laterals forming numerous oblique lines converging toward 

 the sacrum; ventrals smooth, much smaller than dorsals, about fif- 

 teen in a head length; a single very large preanal plate; legs covered 

 above with strongly keeled and mucronate scales ; third finger nearly 

 as long as fourth; subdigital lamellae smooth, 24 under the fourth 

 toe; extended hind leg reaches beyond the elbow; tail slightly com- 

 pressed with six series of very strong mucronate keels at base, this 

 arrangement soon giving way to a mass of high, nearly vertical 

 spines, each one occupying the whole scale, and all nearly the same 

 size, there being no pronounced serial nor verticiallate arrangement; 

 tail underneath with a series of smooth, wide plates, on each side 

 with a single series of mucronate scales ; length of tail not one and one- 

 half the length of body. Color (in alcohol) above vandyke-brown, 

 more sooty on the sides, with about eight irregular and more or less 

 interrupted, narrow, pale cross bars; tail with indications of similar 

 pale cross bars; fingers and toes with very distinct cross bars of dark 

 and pale brown of about equal width; head above and on sides uni- 

 form glossy brown; throat and lower neck more grayish brown, a 

 narrow pale line crossing the commissure from the third supralabial 

 and another from the fifth across the submandibulars to the throat; 

 underside of abdomen, legs, and basal portion of tail pale, the termi- 

 nal two-thirds dark brown like the upper side; scale-row nearest 

 subcaudals pale, forming a pale line on more than basal half of tail. 



Dimensions. 



mm. 



Total length (tip of tail regenerated) 212 



Tip of snout to vent 105 



Tip of snout to ear-opening 25 



Width of head 19 



Vent to tip of tail (regenerated) 107 



Fore leg 34 



Hind leg 46 



Remarks. — The most striking feature of this interesting species is 

 the extraordinary spiny tail. The spines, 2 to 2.5 mm. high and very 

 pointed, stand out in all directions, presenting a most formidable 

 appearance, only second to the highly prickly armature of the upper 

 side of the hind legs. This feature alone will distinguish the species 

 from all others hitherto known. 



