480 



2720. One of the anterior dorsal vertebrae. 



It shows the proportion of the articular surface for the head of the rib which is formed by 

 the neurapophysis. 



2721. A sacral vertebra. 



It shows the proportions of the articular surface for the iliac bones formed by the neur- 

 apophyses and the centrum respectively. 



2722. The last sacral vertebra. 



In this the neurapophyses have coalesced with the centrum as well as with each other. 



2723. The right os innominatum. 



It shows the proportions in which the three constituent bones enter into the formation of 

 the acetabulum. The ischium and pubis have coalesced below. There is a small accessory 

 ossicle wedged between the ischium and pubis behind the acetabulum. 



2724. A section of the cranium of the Asiatic Elephant. 



It exposes the right half of the cranial cavity, the cribriform plate, the superior turbinal 

 bones, and the extensive and complex air-cells that separate the vitreous from the outer table 

 of the cranium : these cells are extended backwards and penetrate the basioccipital and super- 

 occipital. The petrosal is perforated by the entocarotid canal, but is not impressed by any 

 cerebellar pit. There is a well-marked depression in the compartment for the middle lobe of 

 the cerebrum. The anterior parietes of the rhinencephalic compartment are well defined. 



Hunterian. 



2725. A section of the upper parietes of the cranium of an Elephant, showing the 

 thin, compact, outer table, and the extensive mass of air-cells forming the 

 diploe. Hunterian. 



2726. The left nasal bone and contiguous portion of the right one which has been 

 vertically and longitudinally bisected, of an Elephant. 



The entire bone is occupied by large air-cells continued from those of the frontal bones. 

 The wide aperture of communication may be seen at the back part of the left nasal. 



Mm. Brit. 



2727. The left nasal bone of an Elephant, with the thin parietes at the back part 

 broken away to expose the air-cells. Hunterian. 



