131 



The two bonet which intervene between the vomerine and OMB! bonet are the turbinalt : 

 they are beat longitudinally outward* in the fora of tetnicy Under about the termination of 



The spnw of the nasal rertebrm it divided symmetrically u in the Frog, forming the natal 

 bone* (u) : they are elongated, brat plates, with the shorter upper part arching outward* 

 and downwards, completing the olfactory canal above, and with a longer median plate forming 

 a vertical wall, applied closely to itt fdlow, except in front, where the natal procew of the 

 pranaxillary U received in the intenpace of the natalt. 



The acoustic captule remaint in great part cmrtilaginoui : there it no detached centre of 

 ossification in it : to whatever extent thit captule it oaainnJ, it it by a conttnnout extentiou 

 from the alisphenoid. The telerotic captule of the eye it chiefly fibrous, with a thin inner 

 layer of cartilage ; the olfactory captule it in a great measure ottified, at above detcribed. 



MmftHary arek. The palatine (M) or fint piece of thit arch it a strong, oblong bone, 

 having the inner aide of itt obtnte anterior end applied to the sides of the prefrontalt and 

 turbinals, and, near itt potterior end, tending a thort, thick promt upwardt and inwards for 

 ligamentous attachment to the lachrymal, and a tecond similar proeett outward* at the point 

 of suspension of the maxillary bone : between tbete proeettet the p^***"* it perforated, and 

 behind them it terminate* in a point. The chief |>art of the maxillary bone (ti) it continued 

 forward* from itt point of suspension, increasing in depth, and terminating obtusely : a 

 shorter fiuuat it alto, at usual, continued backward*, and trrminatet in a point. The point 

 of taspention of the maxillary form* a thort, narrow, palatine process : the dental branch of 

 the toprainaxillary nerve penetrates the upper and fore part of this proeett, and its chief 

 division escape* by a foramen on the outer and fore part of the maxillary. A ipace occupied 

 by elastic ligament intervene! between the maxillary and the premaxillary (n), which is single 

 and symmetrical, and firmly wedged into the natal intenpace : the anterior expanded part of 

 thit small triangular bone supports two teeth. Thut the bony maxillary arch it interrupted 

 by two ligamentous intervals at the tide* of the premaxillary key-bone, in functional relation 

 to the peculiar independent movements of the maxillary and palatine bonet required by ter- 

 pents during the act of engulfing their usually large prey. 



Two bonet extend backwards at appendages to the maxillary arch ; one it the ' pterygoid ' 

 (M) from the palatine, the other the ectopterygoid (M) from the maxillary. The pterygoid 

 is MmtiimMi from the potterior extremity of the palatine to abut against the end of the tym- 

 panic pedicle : the under part of the anterior half of the pterygoid it beset with teeth. 



The ectopterygoid (M) overlap* the potterior end of the maxillary, and it articulated by itt 

 potteriui obliquely cat end to the outer surface of the middle expanded part of the pterygoid. 



AfsnaVtWtr arc*. The tympanic bone () it a strong, trihedral pedicle, articulated by an 

 oblique upper surface to the end of the mastoid, and expanded transversely below to form the 

 antero-posteriorry convex, transversely concave, condyle for the lower jaw. Thit consists 

 chiefly of an articular and a dentary , with a small ooroooid and splenial piece. 



The articular piece ends obtusely, immediately behind the condyle : it it a little contracted 

 in front of it, and gradually expands to itt middle part, send* op two short ptomsta, then 

 suddenly contract* and terminate* b a point wedged into the posterior and outer notch of the 

 dentary piece. The articular it deeply grooved above, and produced into a ridge below. The 



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