1G2 PROFESSOR STRUTHERS. 



Width of the space (naturally subdivided into the two anterior 

 nares) in Megaptera 13| inches, in B. musculus 10 inches; 

 height, from level of upper edge of vomer, in Megaptera about 

 5 inches, in B. musculus averaging about 5J inches; height 

 from the floor of the vomer,in Megaptera 13 inches, in B. musculus 

 12 inches. That would give the anterior nares in B. musculus 

 as smaller than in Megaptera, although the posterior are larger 

 than in Megaptera. In connection with this, it is to be noted 

 that the blow-hole space in front of the anterior nares is wider 

 in Megaptera than in B. musculus. Also that the cavity of the 

 vomer near the anterior nares is wider as well as deeper in 

 Megaptera; width in Megaptera, inner margin, 7^ inches, in 

 B. musculus, at the inverted margin 4| inches, at the cavity 5^. 

 13, Nasal Cavity. — A very marked difference here is in 

 the much larger deficiency of bone in the outer wall in B. 

 musculus, between the palate, maxillary, and frontal. It is best 

 seen when viewed from the anterior naris. The fissure in both 

 goes back to where the frontal forms the anterior scroll of the 

 orbital cone, and opens there. In Megaptera it extends for- 

 wards for 11 inches, of which 7 are between the palate and 

 frontal, the remainder in a recess in the hinder end of the nasal 

 plate of the maxillary; height 1 inch, 1^ anteriorly; distance of 

 anterior end from anterior nares 9 inches. In B. musculus the 

 fissure begins at the anterior naris, and as a wide gap, has a 

 length of 17 inches, and a height of 4 inches anteriorly, 

 diminishing backwards to 3 inches. It is entirely palato-frontal, 

 except at the anterior end, where it is bounded by the hinder 

 border of the nasal plate of the maxillary. In Megaptera this 

 plate passes back for 12 inches behind the anterior naris. Seen 

 from the palatal aspect, this fissure in Megaptera, 7 inches in 

 length, 1 to 1| inch in height, is between the palate bone 

 below and the maxillary and frontal above, the latter after the 

 maxillary terminates at 3 inches from the root of the orbital 

 cone. In B. musculus it is 17 inches in length, the upper 

 boundary formed by the palate plate of the maxillary for 13 of 

 these, the 4 posterior by the frontal. The total length of the 

 nasal cavity, measured straight from between the upper 

 margins of the posterior and anterior nares, is in Megaptera 

 30 inches, in B. musculus 23, the shortness in the latter owing 



