1864. ] DR. J. E. GRAY ON THE SPECIES OF SEALS. 29 
inner sides, those of the two sides of the jaws being parallel and 
near together in the centre. 
The angle at the hinder lower edge of the lower jaw is much 
more produced, and with a more prominent tubercle, than in either 
Callocephalus hispidus or Pagophilus greenlandicus. 
4. The hinder edge of the palate being concave forwards, and not 
straight and transverse as in Pagophilus, nor angularly cut out as in 
Callocephalus. 
4 
Fig. 1. Skull of Halicyon richardit. 
2. End of lower jaw of Phoca barbata, to show the dilatations and inflexions 
of the lobe over the angle. 
3. End of the lower jaw of Pagomys fetidus. The end of the jaw of Callo- 
cephalus vitulinus is somewhat similar. 
4. Lower edge of the lower jaw of Halicyon richardit. 
5. Lower edge of the lower jaw of Phoca barbata. 
6. Lower edge of the lower jaw of Pagophilus grenlandicus. The jaw of 
Pagomys fetidus is somewhat similar, but much smaller. 
