218 PROCEEDINGS OF THE ACADEMY OF [April, 



Squamation. — Scales in 15 rows, continuous throughout, finely 

 striate, without keels or pits. Gastrosteges 137. Anal divided. 

 Urosteges 42 pairs. Rostral one and one-half times broader than 

 long. Suture between the internasals .6 mm., two-thirds of that' 

 between the prefrontals. Frontal 3.9 mm. long, 3 mm. broad, its 

 distance from the rostral 1.5 mm. Parietal 4.2 mm. long. Preocular 

 1, postoculars 2. Temporals anterior 1, posterior 2. Supralabials 7, 

 third and fourth entering the eye; the sixth the highest. Infra- 

 labials 8, the first pair in contact behind the mental. Anterior 

 geneials touching four labials, one and one-half times as large as the 

 posterior. 



Coloration.— Eody dark brown above, with a vertebral series of 

 twelve very small yellow, black-edged spots, tail with two ; between 

 each pair of spots are three transverse rows of minute yellow dots. 

 Under surface orange. Head with two chevron-shaped bands, the 

 posterior twice the broader; beneath with black V-shaped mark on 

 the anterior geneials, a short longitudinal line on the throat, posterior 

 chevron broadly interrupted. 



Anatomy. — Heart apex at the level of the 28th gastrostege, in 

 terms of body vertebrae this is 20.4% down the column. Anterior 

 tip of the liver at the 39th gastrostege. 



Habitat. — Previously known from three specimens secured on 

 Busuanga Island, Calamianes Group, Philippine Islands. 



This species as at present defined cannot be separated from 0. 

 vertebralis by any single isolated character. The few specimens 

 recorded show that the one to which Boettger's description applies 

 may be distinguished from a tj'pical 0. vertebralis in the following 

 details : internasal suture shorter than the prefrontal ; lateral borders 

 of the frontal converge posteriorly, instead of being parallel; loreal 

 broader than deep; two posterior temporals, sixth supralabial lower 

 and not reaching to the superior-posterior temporal; the vertebral 

 series of spots are much smaller and the transverse rows of minute 

 dots are more distinct. These differences are each well within the 

 range of individual variation. The most pronounced character is 

 the absence of the large spots on the back of the adult 0. schadenbergi, 

 but it does not hold for the young. The distribution of the two 

 broadly overlap in the Southern Philippines. As more specimens 

 are secured there will probably be found examples that will form a 

 complete intermediate series. 



U. S. F. S. Albatross, March 17, 1913. 



