150 



apophyses. After the eighteenth pair the ribs suddenly shorten, and end at the twenty-eighth 

 vertebra as they began at the sixth, as short, straight appendages to the diapophyses : the 

 twenty-ninth vertebra has no ossified ribs, and is a lumbar vertebra. All the pleurapophyses 

 have simple expanded articular extremities. The suprascapula is a broad semiossified plate : 

 the scapula is short and broad, and appears to have coalesced with the coracoid. This bone 

 is much expanded, and has two deep notches anteriorly, and a perforation near the humeral 

 articulation. The ossified stemum is a long narrow piece of bone ; the semiossified part is a 

 broad rhomboidal plate. The innermost toe of the fore-foot has two phalanges, the second 

 three phalanges, the third has four, the fourth five, and the outer one has three phalanges. 

 The elongated iliac bone abuts against the transverse processes of the two sacral vertebrae, the 

 first on the right side and the second on the left side being applied on a plane higher than the 

 opposite processes : that of the first caudal vertebra also abuts against the ilium on the left 

 side. The ilium sends off a tuberosity in front of the sacro-iliac syndesmosis, and it joins the 

 pubis and ischium by a broad suture. The trochanter arises from the inner and back part 

 of the proximal end of the shaft of the femur. There are two ossified patellae in the tendon 

 of the great extensor of the leg. Both tibia and fibula articulate below with the upper sur- 

 face of the transversely extended bone, representing the astragalus and calcaneum coalesced. 

 The phalanges of the hind toes are arranged in the same numerical order as in the fore-foot, 

 viz. 2, 3, 4, 5, 3. 



The second caudal vertebra presents a pair of hypapophyses near its hinder end, indicating 

 the attachment of a haemal arch. This arch is preserved in the succeeding vertebrae, articu- 

 lated to similar hypapophyses. 



In the skull the basioccipital sends down a pair of short, large, obtuse hypapophyses : those 

 of the basisphenoid are larger and abut against the pterygoids : these bones are applied to the 

 back part of the tympanic, and the slender ' columella ' rests upon the middls of their upper 

 surface. 



The parietal is perforated near its anterior border. The postfrontal has a descending post- 

 orbital process. The prefrontal supports an antorbital dermal bone : the small perforated 

 lachrymal is a distinct bone. The nasal and premaxillary are both single or undivided bones. 

 The premaxillary supports eight small conical teeth : each maxillary has nine teeth progress- 

 ively increasing in size and obtuseness to the penultimate one : the left dentary has ten 

 teeth ; the right has twelve teeth, resembling those above. 



Purchased, 



679. An abdominal vertebra of a Monitor Lizard (Far anus variegatus}. 



The centrum is subdepressed, triangular, the posterior articular ball forming the rounded 

 apex : the position of this and of the anterior cup is extremely oblique. The diapophysis is 

 a simple convex tubercle between the articular cup of the centrum and the anterior zygapo- 

 physis. The articular surface of the latter is directed upwards and inwards, that of the 

 posterior zygapophysis downwards and outwards : the neural spine has considerable antero- 

 posterior extent, but is low and truncate. The fore part of its base is a simple ridge, and the 

 back part is without articular depressions. 



Hunterian. 



