BY H. H. SCOTT AND CLIVE E. LORD, 13 



In the evohition of whales, the true zygapo'physes o\ 

 the dorsal series have been ovedapped by the metapophy- 

 ses, that have in oonseqvience suffered a complete atrophy. 



Chevron-hearing Vertehrce. (Plat© VI.) 



These vertebrae beautifully illustrate the reduction of 

 the nietapophyses upon the neural spines as we advance 

 tailward. Hjemad, they carry bony arches to protect the 

 extensive blood vessels that go to nourish the powerful 

 tail — such bones whicn relate to the vertebral haemal arch 

 may be designated either "haemal arches," or chevron 

 bones. 



Sternum of Orca. (Plate VII.) 



An excellent illustration of the sternum of this Orca. 

 is depicted. As will be noted the anterior moiety (manu- 

 briimi) is penetrated by a fossa, an inch and seven-eighths 

 long, and one inch. wide. The articular facets of four ribs 

 are manifest, the next few pairs being articulated by car- 

 tilage to the distal (or ziphoid) end of the sternum. This 

 arrangement is tO' be seen in the articulated skeleton of 

 the pseudorca shown in connection with the description of 

 that animal. 



Ribs. (Plate VIII.) 



To practically illustrate the awful fights that "Killers'' 

 indulge in, and their incidental results, some of the ribs of 

 this Orca, have been photographed. These ribs are paired, 

 and therefore the mutilated rib can be directly compared 

 with its normal congener. Apparently this particular 

 specimen was unusually unlucky, for having early in life 

 broken several ribs upon one side, and tided over the mis- 

 adventure, he lived to face a second similar, but more ex- 

 tensive, fracture upon the other side. This second accident 

 was responsible for the awfiil distortions shown in the 

 picture. 



GLOBICEPHALUS MELAS. 



(For detailed Synonymy see Gray, B.M. Cat. Whales, 

 p. 313, et seq.). 



The specimens representing Globicejjhalus (Nos. 5, 6, 

 7 and 8) consisted of three skeletons, of which two were 

 complete, and a non-associated skull (Plate IX.). These 

 are undoubtedly specimens presented by the late Dr W. 

 L. Crowther, and were evidently carefully prepared in 

 order to show certain essential data. The three specimens 

 may be classed as follows :■ — 



A. (No. 5) shov/s the characters of an adult male. 



B. (No. 6) shows the characters of an adult female. 



C. (No. 7) shows the characters of an immature Glohi- 

 cephalus. 



