Benham. — On the Lesser Sperm Whale. 



159 



Now, as is known, certain structures— the corpora cavernosa 

 — are attached to the pelvis in mammals, and in some whales 

 the bone is almost imbedded in this structure ; but in Cogia I 

 was unable to find it. On the other hand, Wall describes and 

 figures the pelvis as consisting of four bones in a transverse 

 row, an inner and outer, more or less quadrangular plates, 

 on each side. I feel certain that no such bones existed in my 

 specimen, for I looked specially for them. We may, I think, 

 conclude that the pelvis is absent, and in this respect Cogia 

 differs from the sperm whale. 



The length of the vertebral column when the cleaned 

 bones were set in position touching one another is 6ft. 8 in., 

 which, with the skull, measuring 1 ft. 3|in., gives a total of 

 7 ft. 11^ in. for the axial skeleton. To this must be added 

 several inches for the intravertebral discs. The epiphyses are 

 separate. 



The seven cervicals are in this genus entirely fused ; 

 and the usual evidences of the individual vertebrae, such as 

 neural arches, spines, and transverse processes, are almost 

 entirely obliterated. The atlas has its outlines distinct 

 enough, and the neural arch and transverse process of the 

 second vertebra are evident, while the seventh is also well 

 marked out, but the intervening four vertebrae are so 

 fused that it is practically impossible to distinguish their 



boundaries : — 



Cervical Vertebral Mass. 



In this case the total length is measured along the 

 ventral mid-line ; the height, from the ventral mid-line to tip 

 of the neural spine, which projects backwards from the hinder 

 end of the mass, which is, really, the height of the 7th 

 cervical vertebra. The anterior central breadth is across 

 the facets from the occipital condyles. 



This cervical mass is followed by forty-six free vertebrae, 

 giving a total of fifty-three vertebrae, of which thirteen are 

 thoracic, bearing ribs,* nine are lumbar, and twenty-three are 

 caudal, of which the first thirteen bear chevrons. Von Haast's 



* The 13th thoracic has on left side a small articular surface at the 

 end of the transverse process, but on the right fide this is absent. 



