NATRIX 87 



Color in life. — Above olive gray, with three dark stripes run- 

 ning the length of body, separated by two lighter lines ; light 

 stripes are barred with lighter transverse spots at regular in- 

 tervals. Each light stripe covers the equivalent of three scale 

 rows; the dark stripes are much wider and are spotted with 

 dark black spots, those on median stripe being largest and most 

 conspicuous. Outer row of scales has an indistinct row of 

 lighter spots ; two nuchal light spots, quite large, of a creamy 

 yellow ; upper lip cream, with dark spots on sutures of three 

 anterior labials ; lower rim of orbit dark ; chin and lower labials 

 light, with a spot on ninth lower labial ; outer edge of ventrals 

 grayish ; ventrally flesh colored, with numerous dark spots, five 

 or six on each ventral scale. 



Measurements of Natrix spilogaster (Boie) . 



mm. 



Total length 735 



Snqut to vent , .535 



Tail 200 



Width of head 14 



Length of head 23 



Variation. — In the numerous specimens examined the follow- 

 ing variations are evident : The frontal varies from one and a 

 half to one and two-thirds times as long as broad ; there are 1 or 

 2 preoculars ; postoculars, 2, 3 or 4 ; temporals 2 + 2 or 2 + 3, 

 very rarely 1 -j- 2 or 1 -f 3. There are 5 or 6 lower labials in con- 

 tact with the anterior chin shields ; the ventrals vary between 147 

 and 155; the subcaudals vary between 80 and 91. The distinct- 

 ness of the dorsal stripes varies considerably. 



Re-marks. — The species is common in Luzon. It has been re- 

 ported from Negros and Palawan by Boulenger and from Min- 

 danao by J. G. Fischer. Specimens in the collections examined 

 are from Polillo, Luzon, and Camiguin (Babuyan Islands). 

 The species feeds almost wholly on frogs. It is frequently en- 

 countered in the city of Manila. 



MATRIX CHRYSARGA (Schlegel) 



Plate 4, fig. 5 

 Tropidonotus chrysargus Schlegel, Phys. Serp. 2 (1837) 312; GtJN- 



THER, Cat. Col. Snakes (1858) 70; Fischer, Arch. Nat. (1885) 



57, pi. 4, fig. 2; Boulenger, Fauna Brit. India, Kept. (1890) 345; 



Cat. Snakes Brit. Mus. 1 (1893) 258. 

 Tropidonotus jimceus Cantor, Cat. Mai. Rept. (1847) 93; Blyth, 



Journ. As. Soc. Bengal 24 (1855) 716; Gunther, Rept. Brit. India 



(1864) 268, pi. 22, fig. F. 

 Natrix chryaarga Stejnegee, Bull. U. S. Nat. Mus. 58 (1907) 265-, 



Griefin, Philip. Journ. Sci. § D 6 (1911) 2.57. 



