SNAKES. 17 



of a Python (287) and a Boa Constrictor (300) are exhibited to display 

 the claw-like vestiges of the hind limbs and the rudimentary support- 

 ing bones (fig. 12). Eggs of Python sebm (287) are also exhibited. 



The huge Anaconda (Eunectes murinus, 28 1 ) differs from the mem- Table- 

 bers of the genus Boa chiefly by the circumstances that the innermost case - 

 of the three nasal shields of the head is in contact with its fellow, and 

 likewise by the absence of small scales between the labial shields and 

 the eye. Moreover, the muzzle is covered with large shields instead 

 of small scales. During life the pupil of the eye is vertical. 

 Anacondas are both arboreal and aquatic, and thus admirably suited 

 to a life in the flooded forests of tropical America. Their food 

 consists chiefly of mammals and birds, which are captured (mainly 

 at night) both on land and in the water. Specimens are stated to 

 attain a length of over 30 feet ; but the one exhibited is only about 

 18| feet. These Snakes produce their young alive. 



We next come to the Burrowing Snakes, constituting the families Case 14. 

 Typhlopidw, Glauconiidm, Uropeltidm, and Ilysiidm, which are small 

 Snakes of more or less completely burrowing habits, in all but the 

 third of which traces of the pelvis remain. In the Typhlopidcv (303, 

 304) the eyes are vestigial, there are no teeth in the lower jaw, and 

 the body is uniformly covered with small scales. They are entirely 

 burrowing and insectivorous ; and may be regarded as survivors of a 

 generalised group connecting Snakes with Lizards. Most of the 

 species belong to Typhlops (303, 304)- The Glauconiidce differ 

 chiefly by having teeth only in the lower jaw ; the pelvis and hind- 

 limbs are less aborted than in any other Snakes. In the Shield- 

 tails, or UropeltidcB (297-299), which take their name from the 

 large shield terminating the tail, the eyes are very small, the head is 

 not distinct, and the scales on the lower surface of the body are 

 but little enlarged. The Ilysiidw (296) differ by the eyes being 

 generally free, although sometimes covered with scales. There are 

 vestiges of the pelvis and hind-limbs, the latter visible externally 

 as spur-like claws by the vent. Teeth (as in the Uropeltidce) are 

 present in both jaws, but the short tail does not terminate in a 

 shield. Of the few species, Cylhidrophis rufus (296), is exhibited, 

 while one of the best known is the Coral-Snake {Ilysia scytalis) of 

 tropical South America. All the members of this family feed on 

 worms, insects, and small Typldopukc, and produce living young. 

 The more completely burrowing species of this group are not unlike 

 large worms in appearance and habits, for which, indeed, they are 

 not infrequently mistaken. 



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