BY H. H. SCOTT AND CLIVE E. LOl:D, 13 



In the evolution of whales, the true zygapophyses ox 

 the dorsal series have been overlapjDcd by the mctapophy- 

 ses, that have in consequence suffered a complete atrophy. 



Clievron-hearin;/ Vertehra'- (Plate VI.) 



These vertebrae beautifully illustrate the reduction of 

 the metapophyses upon the neural spines as we advance 

 tailward. Haemad, 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 ai'ch 

 may be designated either 'haemal arches, " or chevron 

 bones. 



Stem inn of Orra. (Plate VII.) 



An excellent illustration of the sternum of this Orca 

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

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

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

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

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

 aiTangement is to be seen in the articulated skeleton of 

 the pseudorca shown in connection with the description of 

 that animal. 



Fihx. (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 fare a second similar, but more ex- 

 tensive, fracture upon the other side. This second accident 

 was responsible for the awful distortions shown in the 

 picture. 



GLOBICEPHALUS MELAS. 



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

 p 313, ef seq.). 



The specimens representing C/nhirfjiIid/iiK (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 specim3ns 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) shows the characters of an adult male. 



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



C. (No. 7) sho\vs the characters of an immature Glohi- 

 n plioliix. 



