10 PLEISTOCENE MAMMALIA. 



CHAPTER III. 

 Felis spelcea — Os innominatum, PL III, fig. 1. 



We have met with but four specimens of this bone from the British Pleistocene 

 deposits, all more or less imperfect. Of these, three were obtained by Messrs. Williams 

 and Beard out of the bone-caverns of the Men dip Hills, and are preserved in the Taunton 

 Museum, while the fourth and largest, which we figure, is derived from the brick-earth on 

 the south side of the Thames Valley, at Slade Green, near Erith, in Kent, and is in the 

 national collection. It consists of the ilium and ischium, tolerably perfect, and a portion 

 of the OS pubis of the left side. 



The ilium may be described as resembhng the blade of an oar in form, slightly con- 

 cave on the external, and nearly flat on the internal or sacral surface ; the parts answering 

 to the crest (fig. 1, a, a) and spinous processes {p, U, b") forming the strong rounded 

 and raised border of the blade. The external surface is traversed by a longitudinal ridge 

 (c, c) that strengthens the attachments of the glutei muscles. This ridge is very slightly 

 developed in the specimens from the Mendip caverns, while in that figm-ed it reaches a 

 maximum development. The symphysis of the sacrum extends slightly along the upper 

 edge of the shaft or body, and takes the form of a small spine or process at b. This 

 shaft or body (c, d) is massive, and of great strength, flattened internally and rounded 

 externally, and ending inferiorily in a sharp free edge {d). The anterior inferior spinous 

 process {e) varies in form and size in the different individuals, but bears a general 

 resemblance to that of the lion. 



The portion (/) of the os innominatum that composes the apex of the sacro-ischiatic 

 arch immediately above the acetabulum is convex and rounded, and without any ridge. 

 It forms the connection between the shafts of the ilium and ischium. That of the latter 

 {ci,h) is prismatic in form, tapering posteriorly and expanding downwards and transversely 

 into a broad triangular blade, the anterior edge of which forms the posterior boundary (?) 

 of the pubic arch. The ischial spine {k) is a small pyramidal process immediately above 

 the posterior edge of the acetabulum. 



