am. W. H. FLOWER ON THE OSTEOLOGY OP THE SPERJI-WHALB. 365 



firm this description. lu addition to the single bone which accompanied the skeleton, 

 Mr. Crowther has presented to the Museum two other pelvic bones, taken also from 

 adult male animals ; but neither of them bears traces of any original segmentation. 



They all present the general characters common to the corresponding bones in other 

 Toothed Whales, but have, as is so frequently the case, strongly marked individual 

 peculiarities. They are all more or less compressed, slightly expanded at one end, 

 which was tipped with cartilage, and present some modification of a sigmoid curve. 

 The bone which belonged to the skeleton (see PI. LX. figs. 5 and 6) is 14" long ; at the 

 middle its diameters are l"-3 and 0"'95 ; at the expanded end 2 ' and l"'l. Its surface 

 generally is simple and smooth ; but at 4" from the smaller end one of the margins rises 

 into a triangular elevation surmounted by two short rough processes having different 

 directions. 



Of the two other bones (which, though apparently belonging to opposite sides of the 

 body, are stated to have been taken from different individuals), one (PI. LX. fig. 7), 

 though closely corresponding in actual length and thickness to the last, is so strongly 

 curved that in a straight line its two extremities are but 12" apart. Its surface is more 

 angular, presenting several strong longitudinal ridges and grooves. Near the middle of 

 its greatest convexity is a small but prominent spine 0"-4 in length ; but otherwise there 

 is no appearance of the lateral process so well marked in the last. Both ends were 

 tipped with cartilage. 



The third bone (fig. 8) is the largest of the three. It is distinguished by a very 

 regular sigmoid curve, by its smoothness, and the absence of all spine or process, and 

 especially by its great compression, and corresponding width in the opposite direction. 

 Its length is 14""1, its diameters at the middle 2"-4 and 0"-9, at the broader end 3"-7 

 and 0''9. As in the first-described specimen, the more pointed extremity is smoothly 

 rounded and evidently complete ; the condition of the other end shows that it had a 

 cartilaginous continuation. 



The principal part played by these bones in the economy of the animal would 

 prepare us to find that they presented considerable differences according to the sex of 

 the individual to which they belonged ; but in those genera in which the entire magni- 

 tude of the male and female differs but little, we do not generally find a very marked 

 difference in the pelvic bones. Thus, in two perfectly adult Porpoises of neai-ly equal 

 dimensions, the length of the pelvic bones of the male was 5^', of the female 4^"*. In 

 the Hunterian collection is a dried preparation of the penis of a Hyperoodon with the 

 ischial bones still attached to the crura. The animal, from the size of these and other 

 parts preseiTcd in the Museum, as well as from a statement of Hunter, must have been 

 much larger than the ordinary ffi/j^eroodoii rostratum, and probably belonged to the 

 supposed species called //. latifrons, Gray, regarded by Eschricht as the adult male of 



* It appears, according to Eschric-ht's observations, that in the genus Orea the pelvic bones show consi- 

 derable sexual differences. (Recent Mem. on Cetacca, Ray Soc. 1866, p. 176.) 



VOL. Vr. PART VI. 3 E 



