59^ OPHIDIA 



CHAP. 



COW ; but common sense tells us where to draw the line when it 

 comes to the swallowing of the prey. Small game, although of 

 a bulk apparently far too big for the snake, is so crushed and 

 mangled tliat it is turned into the shape of a sausage preparatory 

 to the long process of swallowing. The Boidae lay eggs, and 

 some species incubate them, or rather the female coils herself 

 round them for the sake of protection. Xo appreciable amount 

 of extra warmth is developed. Unfortunately the observations 

 of one of the best cases on record ^ were conducted so imperfectly 

 that they are of little value. 



Sub-Fam. 1. Pythoninae. — With a pair of supra-orbital 

 bones, intercalated between the prefrontal, frontal, and postfrontal 

 bones. The sub-caudal scales are mostly in two rows. The pre- 

 maxilla often carries a few small teeth. 



The Pythoninae, comprising about twenty species, are 

 restricted to the Palaeotropical and Australian regions, with the 

 sole exception of Loxocemus hicolor in Southern Mexico. 



Tython, the principal genus, has teeth on the premaxilla. 

 The rostral, each of the anterior upper labials, and some of the 

 lower labial shields, contain a deep, probably sensory, pit. The 

 maxillary and mandibular teeth are long, but decrease from 

 before backwards. The head is distinct from the neck, and is 

 covered with symmetrical shields or with small scales. The 

 scales of the body are small and smooth. The tail is short 

 and prehensile ; below with two rows of scales. The pupil of 

 the eye is vertical. The range of the genus extends over the 

 whole of the Palaeotropical and Australian regions, excepting 

 Madagascar and New Zealand. 



P. spilotes, the " Carpet Snake " of Australia and New Guinea, 

 is mostly beautifully marked, but is suliject to much variation in 

 colour. The more typical specimens are Idack above, each scale 

 with a yellowish dot, with yellow spots or combinations of dots, 

 more or less arranged in rows. The under parts are yellow. It 

 reaches a length of about two yards, and spends a great part of 

 its time in trees. 



P. reticidatus is the commonest species in Indo-China and in 



the Malay Islands. Four upper labial shields of each side are 



pitted. The specific name refers to the bold, dark, lozenge-shaped 



markincs upon the lir,diter vellowish or brown ground. A black 



' W. A. Forbes. I'.Z.S. ISSl. p. 960. 



