178 PllOFESSOR STPvUTHEnS. 



receive a large thumb. By means of this beam the process retains 

 its tliickness till close to the top. The beam goes nearly straight 

 down, and is lost at the base of the process. The inner edge of the 

 gi'oove is the anterior border of the process, and is continued as the 

 anterior border of the body of the bone. The border of the process 

 is sharp. Just in front of the base of the process the border of the 

 bone becomes rapidly thickened. This 2^''^^'(^oronoid thickening ex- 

 tends for about 5 inches, and is then gradually continued on the 

 upper edge of the body. Viewed from the side this part is slightly 

 convex upwards. The posterior edge of the coronoid process is thin 

 at the middle third, and on about the lower fourth becomes thick- 

 ened to I inch, as the anterior part of the post-coronoid roughness. 

 The rounding of the top of the process corresponds pretty well to 

 the form of the ends of the four fingers laid together, the fore finger 

 to the front. Viewed from above, the top has a thick, somewhat 

 triangular form, owing to the beam and the groove.] 



In Megaptera, besides its much less height than in B. musculus 

 (in Megaptera 3| inches behind, 1\ in front), the coronoid pro- 

 cess differs in form from that of B. musculus. It is a blunt 

 triangle, the anterior and posterior borders both gently concave 

 till near the top, the anterior the most sloping border, so that 

 the process seems to point a little backwards. It is more everted 

 than in B. musculus, and a little concave on the outer surface. 

 The posterior border of the process is thin throughout (f inch, 

 increasing to 1 inch below). The top is less pointed than in 

 B. musculus, and is thick, averaging | inch, more behind, thinner 

 in front. There is no beam on the outer surface, except a little 

 thickening at the top, and consequently no groove on this 

 surface. The pre-coronoid thickening is more marked than in 

 B, musculus, 8 to 9 inches in length, in its posterior half 1 inch 

 thick, and raised | inch above the level of the border behind 

 and before. It is rough, with an irregular depression dividing 

 it longitudinally, the outer edge of the depression continuous 

 with the anterior edge of the coronoid process. The depression 

 runs back on the inner side of the anterior border of the coronoid, 

 leaving a groove between, which, however, does not correspond to 

 the groove noted in B. musculus. 



Neck. — The neck is about the same length in both, but an 

 elevation on the upper border in Megaptera, at and in front of 

 the middle, forms a marked difference, in contrast with the general 

 gentle concavity in B. musculus. This 2^ost-coronoid elevation 

 is about 7 to 8 inches in length, rising gradually before and 



