RHYNCHOCEPHALIA. 619 



like in appearance, it measures from one to two feet 

 in length, has a compressed crested tail, is dull olive-green 

 spotted with yellow above and whitish below. It is now 

 rare, but is preserved in some small islands off the New 

 Zealand coast. It lives in holes among the rocks or in 

 small burrows, feeds on small animals, and is nocturnal in 

 habit 



FIG. 337. Heart and associated vessels of tortoise. After Nuhn. 



r.a., Right auricle ; superior venae cavae (s.v.c.) and inferior vena 

 cava (t.v.c.) enter it. r.v., Right half of ventricle ; pulmonary 

 arteries (/*.#.) and left aortic arch (l.ao.) leave it ; ccel., coeliac ; 

 d.ao., dorsal aorta. l.a. t Left auricle ;/.#., pulmonary veins 

 enter it. l.v.. Left half of ventricle ; right aortic arch (r.ao.), 

 giving off carotids (c.) and subclavians (s.cl.). 



The skull, unlike that of any lizard, has an ossified quadrato-jugal, 

 and therefore a complete infra-temporal arcade : the quadrate is firmly 

 united to pterygoid, squamosal, and quadrato-jugal; the pterygoids 

 meet the vomer and separate the palatines; there are teeth on the 

 palatine in a single longitudinal row, parallel with those on maxilla 

 and mandible, and the three sets seem to wear one another away; 

 there is also a single tooth on each side of a kind of beak formed by 

 the premaxillse ; the nares are divided. 



The vertebrae are amphicoelous or biconcave, as in geckos among 

 lizards and in many extinct Reptiles. Some of the ribs bear uncinate 



