686 YOUNG SPECIMEN OF OliXITHORHYXCHUS AXATIXUS, 



complete circle as shown in Poulton's plate.) The dorsal contour 

 line from tip to tip as already stated measures 80 mm., while the 

 distance between the extreme points of the curved body 

 (vertex to root of tail) in a straight line, is 40 mm. There is no 

 distinct cervical constriction, a " neck " being practically absent. 

 The distance from the tip of the snout to the anterior border of 

 the forelimb is 15 mm. 



The maximum breadth of the head is 11 mm. The snout is 

 sharply separated from the rest of the head by the developing 

 lappet-like fold of integument which forms so prominent a feature 

 at the base of the adult muzzle. This has here the character of 

 a collar-like ridge and is continuous all round the root of the 

 muzzle, though just at or above the elevated angles of the gape 

 which reach up to it, it is somewhat lower than elsewhere and is 

 slightly overlapped by the somewhat projecting hinder angle of 

 the upper lip or maxillary lobe. The length of the snout is pro- 

 portionately small both to the rest of the head and to its own 

 width. It is 4-5 mm. long from tip to basal groove in front of 

 lappet, while it measures 6-5 mm. in width. 



The gape has a sinuous outline and is a simple fissure through- 

 out Avhich is almost closed. No trace of the tongue can be seen 

 from the outside nor any vestige of the integumentary folds 

 which, according to Owen, united the upper and lower lips across 

 the angle of the mouth in his specimen. The upper lip through- 

 out slightly overhangs the sinuous gape, whose posterior extremities 

 turn somewhat dorsally where they reach to the collar-like lappet. 

 The nostrils are situated dorsally and about 1-5 mm. behind 

 the anterior end of the snout. Between, and just in front of the 

 interval betwixt these, the dorsal surface of the snout is sharply 

 elevated into a very prominent " caruncle," which also projects 

 very slightly forward so that it almost reaches the coronal plane 

 of the anterior margin of the snout. The tip of this caruncle is 

 whiter than its surroundings and evidently forms the epidermal 

 covering which was presumed by Owen to exist over the "minute 

 fleshy eminence lodged in a slight depression" and "surrounded 

 by a discontinuous margin of the epidermis " observed by him. 



