TROPIDOPHORUS 241 



those on belly; scales under tail broadened; a single, large pre- 

 anal; limbs strong, fourth toe with twenty smooth lamellae be- 

 low; auricular opening a little more than half eye. 



Color in life. — Body above reddish brown, barred across back 

 with a series of indistinct irregular crossbands, not or scarcely 

 visible on sides; sides darker, with bright yellow spots, seldom 

 more than two or three scales in size; lateral scales flecked with 

 small yellow or orange spots ; head lighter brown without mark- 

 ings above; lips and underside of throat and chin grayish blue; 

 abdomen and underside of limbs yellowish white; basal third 

 of tail rather pinkish. 



Measurements of Tropidophorus rivularis Thylor. 



mm. 



Total len^h 197 

 Snout to vent 91.5 



Tail (regenerated) 105.5 

 Snout to foreleg 35 



Axilla to groin 45 

 Foreleg: 26 



Hind leg 39 



Variation, — The several specimens from the type locality agree 

 fairly well in scalation. One specimen shows the two inter- 

 parietals fused into one. Several specimens taken near Zam- 

 boanga differ from typical specimens in having the head shields 

 almost smooth and the two interparietals fused. This character 

 of the type is probably variable. A younger specimen with the 

 tail intact measures as follows: Total length, 160 millimeters; 

 snout to vent, 59; tail, 101. The largest taken measures 101 

 millimeters from snout to vent. 



Remarks. — This species and T. misaminius Stejneger are 

 closely related to Tropidophorus brooki Gray, of Borneo. Stej- 

 neger has pointed out the differences between T. misaminius and 

 T. brooki."^ 



The present species differs from both by the presence of 

 a series of small scales above the upper labial scales, and 

 the strong, deep, diagonal groove in front of the eye. The 

 species is common in the small mountain streams of the upper 

 Agusan Valley. These skinks live for the most part under partly 

 submerged rocks and logs, or in small holes in the banks of 

 streams. They are even more aquatic than T. grayi and in- 

 variably take to water when disturbed. I have found the spe- 

 cies only at Bunawan, Agusan, Mindanao, and at Zamboanga. 



* Proc. U. S. Nat. Mus. 34 (1908) 203, 204. 



161466 16 



