Sheppard : Notes on the Skeleton of Sibbald's Rorqual. 235 



read a paper to the London Zoological Society ' On Physalus 

 sibbaldii Gray .' This is printed in the Society's 'Proceeding's,' 

 for 1865, pp. 472-474. Professor Flower agrees with Gray in 

 regarding the Hull skeleton as a distinct species, and he points 

 out that it coincides precisely with a specimen which had then 

 recently been acquired by the trustees of the British Museum, 

 from the collection of the late Professor Lidth de Jeude, of 

 Utrecht, to which Flower had given the name of Physalus lati- 

 rostris, but he withdrew this name in favour of the one previously 

 given by Gray to the Hull specimen. Flower goes on to say : 

 ' The Hull and the Utrecht skeletons are at nearly the same 

 stage of growth ; the epiphyses are disunited in almost all the 

 vertebrae, as well as on both ends of the humerus, radius, and 

 ulna. In the Hull specimen the ossification of the transverse 

 process of the second cervical vertebra has proceeded so far as 

 to surround the vertebral foramen ; in the Utrecht skeleton the 

 foramen is still open, though only by a narrow fissure on one 

 side. I should judge from this that the former is rather the 

 older of the two. In both, the transverse processes of all the 

 remaining cervical vertebras are incompletely ossified, and not 

 united at their ends by bone. In general size and proportions 

 the two specimens very nearly correspond, the advantage being 

 in favour of the Hull one, which is stated to have a total length 

 of 47 feet, the cranium being 10 feet 6 inches, while the Utrecht 

 specimen is about 43 or 44 feet long, the skull being 9 feet 

 10 inches. Either example, when full grown, would probably 

 be not far short of 60 feet, or somewhat less than the averag'e 

 size of the common species.' 



' The two skeletons agree in possessing 64 vertebrae, both 

 being in this respect, fortunately, complete. In P. antiqiiorum 

 [another species] the number never appears to exceed 62. In the 

 Hull skeleton the foramen in the transverse process of the axis is 

 very small, and nearly circular, about 2 inches in diameter. In 

 the Utrecht specimen it is more oval, 3^ inches high, and 

 4^ inches long. This difference in so variable a part is pro- 

 bably only individual. The four following vertebrae have in 

 both a converging upper and lower process, which are, as said 

 before, incomplete and ununited. In the Hull specimen the 

 seventh has a short but distinct inferior process, which in that 

 at Utrecht is represented by a mere tubercle. In the terminal 

 caudal vertebrae there is a great similarity ; the last is very 

 small, short, and disc-like ; the second from the end is of similar 

 form, but somewhat larger; the third presents a sudden increase 



1901 August 2. 



