Anstvers to Correspondents 



67 



strong and slope directly forwards, as if for digging. The incisor 

 teeth are of less service in the pig than in most animals, and 

 are only exceptionally used for biting or grazing. The pig 

 makes great use of the snout, and the nasal bones are strong 

 and prominent. The molar teeth are well adapted for 

 chewing, and are usually worn flat on their surfaces. Pigs 

 champ but do not ruminate. They are, for the most part, 

 root-eaters. The rim of the orbit is always imperfect. The 

 normal dentition is three incisors, one canine, and seven 

 molars in each jaw. If the upper canine is extracted the 

 lower one will grow into a complete circle and reach the gum 

 close to the root of the tooth. When thus curved it forms 

 an ornament much valued in Fiji. 



SKULL OF THE BABIRUSSA. 



Note especially that the tusk of the upper jaw grows up- 

 ward from the first. No part of it is directed into the mouth. 

 This tusk is of extraordinary size, and it curves upwards so 

 as to touch, and sometimes even to pierce, the skull. They 

 are, as compared with those of other swine, slender tusks, more 

 especially the under ones. The upper tusk grows through 

 the skin of the upper lip. In old animals, when it is well 

 curved, it must be useless as a weapon. It may serve to 

 protect the eyes when the animal rushes through brushwood. 

 In the female the tusks are small. 



ANSWERS TO CORRESPONDENTS, &c. 



CONCHOLOGIST. — Your shells are Helix nemoralis (immature), 

 Hyalmia ( Vitrea) pitra, and Bultminus obscurus. Vitrea pura is a 

 much smaller shell than V. nitidula, the latter may be distinguished 

 from V. radiatula by the striae not being continued from whorl to 

 whorl. B. obscurus is much smaller than any member of the genus 

 Clausilia. If you examine in May the trunks of beech trees growing 

 on calcareous soils you will find B. obscurus and Clausilia laminata 

 ascending them in large numbers to spend the summer aloft, coming* 

 down again in October to go into hybernation at the base of the trees 



