SPHENOMORPHUS 167 



species. Many are rather local in distribution and doubtless 

 many species remain undiscovered, especially in the northern 

 part of Luzon, in Mindanao, and on high mountains. Most of 

 these skinks are terrestrial in habit, although Sphenomorphus 

 arbor ens, and to some extent S. acutus and S. variegatus, are ex- 

 ceptions in this respect. Sphenomorphus fasciatus is a burrow- 

 ing form and is never seen except when disturbed under some 

 log, rock, or plant. In consequence of this habitat the eye is 

 reduced somewhat in size. Most of the species of Sphenomor- 

 phus are rather diminutive. The largest form is S. jagorii 

 subsp. grandis; it reaches a length of more than 260 millimeters. 

 Sphenomorphus steer ei, S. decipiens, S. luzonensis, S. atrigularis, 

 S. hiparietalis, and S. moellendorffi probably never attain a length 

 of 100 millimeters, and most of the individuals are much shorter. 



Key to the Philippine species of Sphenomorphus Fitzinger. 

 a^. Frontoparietal single. 



6\ Anterior frenals, 2, superimposed.* 



c\ Six supraoculars; 26 to 30 scale rows; 32 to 34 subdigital lamellae; f 



180 millimeters in length S. acutus (Peters) (p. 168). 



c\ Four supraoculars; 40 scale rows; 16 to 19 subdigital lamellae on 

 longest toe; 98 millimeters in length. 



S. curtirostris Taylor (p. 170). 

 6^ Anterior frenal single. 



c\ Five supraoculars; 34 to 36 scale rows; 22 lamellae; 166 millimeters 



in length S. coxi Taylor (p. 173). 



c^ Four supraoculars. 



<f. Twenty-eight scale, rows; hind leg equals distance between eye 

 and foreleg; 80 millimeters in length. 



S. luzonensis (Boulenger) (p. 175). 

 d\ Thirty-six scale rows; hind leg equals distance between nostril 

 and foreleg; 80 millimeters in length. 



S. decipiens (Boulenger) (p. 176). 

 d\ Thirty to 34 scale rows; 10 lamellae; 70 millimeters in length; 



2 pairs of parietals S. biparietalis Taylor (p. 177). 



d\ Thirty-two scale rows; 16 lamellae; 90 millimeters in length. 



S. moellendorffi (Boettger) (p. 179). 

 d\ Thirty scale rows; 12 lamellae; 74 millimeters in length. 



S. steerei Stejneger (p. 180). 

 a\ Frontoparietal double. 



6\ Anterior frenals, 2, superimposed; 5 supraoculars. 



c\ Forty-two scale rows; 23 lamellae; 148 millimeters in length. 



S. llanosi Taylor (p. 182). 

 c\ Thirty-eight to 40 scale rows; 20 to 25 smooth lamellae; 139 



millimeters in length S. variegatus (Peters) (p. 184). 



b\ Anterior frenal single. 



* Sphenomorphus steerei and S. curtirostris vary in the condition of the 

 anterior frenal. See descriptions. 



t The count of subdigital lamellae is for the fourth toe. 



