376 AQAMlDiE. 



the median dorsals, or more enlarged ; supraorbital scales very small,, 

 granular, or nearly as large as median dorsals; nostril directed 

 forwards and slightly upwards ; nasal separated from its feUow by 

 three to five longitudinal series of scales. Dorsal scales homogeneous, 

 small, granular on the sides, enlarged, flat and subimbricate, smooth 

 or feebly keeled on the vertebral region. Gular scales smooth or 

 indistinctly keeled ; pectoral and anterior ventral scales strongly 

 keeled and mucronate, posterior ventrals smooth. Scales on upper 

 surface of limbs keeled. Both sides of third and fourth toes with a 

 strong fringe of acute lobules. Tibia longer than the skull. Tail 

 swollen and much depressed at the base, then roundish depressed, 

 tapering to a rather fine point, the end curling upwards ; except 

 on the basal portion of the tail, the scales are keeled. Greyish 

 above, spotted, marbled, or vermiculated with blackish ; sometimes 

 with whitish, dark-edged spots forming ocelli on the back ; tail 

 inferiorly with black bars alternating with white ones of nearly 

 equal width ; lower surfaces white. 



The specimens faU into two distinct forms, which are perhaps 

 entitled to specific separation : — 



A. (P. caudivolvulus.) Occipital scales much larger than dorsals. 

 Tail not quite twice as long as the distance from gular fold to 

 vent. Three to five black spots under the tail. 



Total length 114 millim. 



Head 11 „ 



Width of head 11 „ 



Body 38 „ 



Fore limb 23 „ 



Hind limb 40 „ 



Tail 65 „ . 



Shores of the Caspian Sea ; Turkestan ; Tibet. 



a ft. 5 . Astrachan. 



c, ^ . Turkestan. M. Severzow [C.]. 



^^ ^ . Ladak. Messrs. v. Schlagintweit [C.]. 



B. {P. ocellatus.) Occipital scales not larger than the largest 

 / dorsals. Tail more than twice as long as the distance from 

 / gular fold to vent. Six to nine black spots under the tail. 



Total length 125 millim. 



Head 12 „ 



Width of head 12 „ 



Body 38 „ 



Fore limb 24 „ 



Hind limb 43 „ 



Tail 75 „ 



Eastern Central Asia. 



a-b. 2 • Shore of Lake Alakul. St. Petersburg Museum. 



e-e. S- West Khara-Kum. St. Petersburg Museum. 



f-g. Yg. Lppsinskaja Staniza. St. Petersburg Museum. 



