Ml 



tin-in. Id the Aptrryx the small lacrymal boon are represented by two com- 

 pimd plates of bone descending obliquely forwards from the intrrior extremities of the 

 tmiiuls, and are articulated below to a (mall depression in tin- maxillary plate. Thry arc 

 each pierced by a single small foramen. The frontal, naial. and intermaxillary bones form 

 one (iintiituoas bony piece, too lUtmg to admit of any clastic yielding movrinrut between the 

 upper jaw and cranium. The natal and the upper or mcaial portion of tin- intermaxillary 

 bow* form an elongated depressed narrow process, convex abore, and with the outer margin* 

 bent inward* beneath the long na*al psssagrs. of which they form the outer and part of tin 



Tht lower jaw presents all the uiual ornithic characters with the Strulhious modification* 

 traceable in the individual peculiarities. The transversely expanded angular and artiruUr 

 extremities offer the inwardly extended process for the attachment of the pterygoidei nuuclr* : 

 the superior transverse plate behind the articular surfaces is thin and concave towariN il 

 neatus uditorius externus, and is lined by the mucous membrane of tliat pasaage, of which 

 tk farm* part of the bony pahetes. There are two distinct narrow oblique artiruUr nurfare*. 

 eoncave in the longitudinal and convex in the transverse direction! ; the internal one is the 

 largest, and behind this there is a small excavation into which a small process of the air-sac 

 - laMg the tympanum is continued ; and this is the only pan of the skeleton not immediately 

 concerned in the formation of the organs of bearing or smelling into which air is admitted. 

 The entry to the air-cells in the lower jaw of the Ostrich is situated in the part cormpumliiig 

 to the above depression or sinus in the jaw of the Aptrryx. Traces of the compound struc- 

 ture of the lower jaw are very evident in that of the Apteryx, and the limits of the angular, 

 articular and coroooid pieces may be in part defined. There is a linear vacancy, bounded by 

 the surangular and angular pieces behind, and by the bifurcate commencement of the man 

 dibular or dentary piece in front : the surangular is compressed, and sends upwards n very 

 slightly elevated coronoid ridge. A second narrower fissure occurs between the thick iplenial 

 element and the upper fork of the maudibular piece. 



The relations of the modifications of the skull of the Apteryx to its peculiar habit* and 

 kind of food are well-marked and very easily traced ; those which concern the maxillary por- 

 tions have already been noticed in the account of the digestive ytcm, and I need only add 

 here, that the anchylosed condition of all the parts concerned in the formation of the upper 

 mandible is more complete than in the larger Strutkiomidte, and relates to the greater force 

 ith which the beak is used in obtaining the fnod. 



The nocturnal habits of the Apteryx, combined with the necessity for a highly developed 

 organ of smell, which chiefly compensate* for the low condition of the organ of vision, pro- 

 duces the moat singular modifications which the skull presents, and we may say that those 

 cavities which in other birds are devoted to the lodgement of the eyes, are here almost ex- 

 dusively occupied by the nose. 



The spinal column is relatively stronger, especially in the cervical region, than in the larger 

 SinHuomida : in consist! of fifteen cervical, nine dorsal, characterized by moveable ribs, and 

 twenty-two remaining vertebra; in the sacral and caudal regions. 



The dorsal vertebra- are arranged in a straight line, and slightly increase in breadth to the 

 seventh ; the transverse processes of the eighth and ninth suddenly diminish. The third. 



