156 



slightly festooned borders of the jaws, between this species and the Crocodilus Schlegelii from 

 Borneo. Number of alveoli in the premaxillary, 44 ; in the maxillary, 13 13 ; in the 

 dentary, 15 15. 



Presented by Sir Wm. Blizard, F.R.S. 



711. The skeleton of a young Sharp-nosed Crocodile (Crocodilus acutus). The 



number of alveoli in the premaxillary is 5 5 ; in the maxillary, 14 14 ; in 

 the dentary, 15 15. 



The rib of the axis is expanded and sub-bifurcate at its proximal end, but is slightly ad- 

 vanced in position, and articulates with two transverse processes, a parapophysis and diapo- 

 physis of the odontoid. The ribs of the five succeeding vertebrae are short and developed 

 forwards and backwards, overlapping each other. The ribs of the eighth and ninth vertebrae 

 are long, slender and pointed, but do not articulate with the sternum. This character is 

 presented by the seven succeeding ribs, the semiossified haemapophyses of which are divided 

 into two parts. The cartilaginous appendage of the eighth rib joins that of the preceding 

 one. The ribs of the eighteenth and nineteenth vertebrae are again free or floating. The 

 rudiments of the ribs of the twentieth vertebra have not been preserved, but the surface at the 

 end of the long diapophysis indicates that they existed. The diapophyses of the next four 

 vertebrae seem not to have had pleurapophyses, and represent lumbar vertebrae. There are 

 two sacral vertebrae, characterized like those in the Gavial. Diapophyses are developed from 

 the fourteen anterior caudal vertebrae : the haemapophyses commence at the interspace between 

 the second and third vertebrae. 



Mm. Heaviside. 



712. The skull of the Sharp-nosed Crocodile (Crocodilus acutus), in three transverse 



sections. 



One is taken through the prefrontal and lachrymal bones, immediately in front of the 

 orbits, and shows the junction of the descending or neurapophysial plates of the prefrontals 

 with the upper vomerine or coalesced portion of the pterygoids. The second transverse 

 section is taken between the thirteenth and fourteenth tooth, through the nasal, maxillary, 

 vomerine, and palatine bones. It shows the commencement of the posterior respiratory 

 canals formed by the external lamella of the vomer, which arches outwards to join the 

 external ascending plate of the palatines, and which is continued backwards by the vomerine 

 tubular portions of the pterygoids. In the anterior part of the section the vomerine bones 

 may be seen extending forwards to join the nasal processes of the maxillaries. The maxillary 

 and palatine sinuses are exposed by the anterior section : the maxillary sinuses are separated 

 from the nasal cavities by a thin, vertical, bony plate. They communicate by an oval aper- 

 ture at their back part with the posterior part of the nasal cavities. A palpebral ossicle is 

 displayed at the superior and anterior part of the orbit. Number of alveoli in the pre- 

 maxillary 5 5, in the maxillary 14 14. 



Presented by Prof. Owen, F.R.S. 



