512 PROF. FLOWER ON PHOCA HISPIDA. [June 6, 



whereas in P. vitulina, which has not this expansion, they diverge 

 rapidly immediately behind the symphysis. I must, however, re- 

 mark that some examples of the latter species present in this region 

 a considerable approximation to the form met with in the other 

 members of the genus. 



The principal dimensions of the skull are as follow : — 



rnillims. 

 Length of cranium, from anterior extremity of praemaxilla to 



occipital condyle 183 



Greatest breadth across zygomata 120 



Breadth of skull in temporal fossse, just above the posterior 



roots of the zygomata 90 



Breadth of frontals between orbits 8 



Breadth of both nasals at middle of their length 9 



Length of nasal 44 



Breadth of occipital condyle 62 



Breadth of foramen magnum 26 



Height of foramen magnum 21 



Greatest length of malar bone 49 



Breadth between external borders of lower margin of external 



auditory meatus 112 



Shortest distance between the auditory bullae (near their an- 

 terior ends) 33 



Antero-posterior length of auditory bullae 37 



Length from lower border of foramen magnum to bottom of 



notch in middle of hinder border of palate 100 



From the last-named spot to the anterior extremity of the 



praemaxilla 75 



From anterior extremity of prsemaxilla to hinder edge of pos- 

 terior molar tooth 62 



From anterior extremity of prsemaxilla to anterior margin of 



orbit 53 



Breadth between inner surfaces of posterior upper molar teeth 39 



Breadth between upper canines 16 



Length of ramus of mandible from anterior extremity to pos- 

 terior edge of condyle 117 



From anterior extremity to apex of subangular process .... 101 

 From the top of the coronoid process to the apex of the sub- 

 angular process 55 



From the posterior edge of the condyle to the anterior edge 



of the masseteric depression 45 



Height of ramus opposite last molar tooth 21 



Length of symphysis 22 



Width between apices of subangular processes 63 



Width between outer edges of condyles t 100 



