160 BAL^NOPTERID^. 



^ The short haleen forms the front part of the series, in which the 

 layer in the middle is dark slate-coloured, and the intermediate- 

 sized hlades are more or less slate-coloured on the outer and white 

 on the inner side. The hreast-bone is lozenge-shaped, with a large 

 central perforation. 



Mr. Heddle gives a long account of this species in his paper in the 

 ' Proceedings of the Zoological Society' above referred to. 



*** Tlie upper and lower lateral processes of the third, fourth, artdjiflh 

 cervical vertebree short, strong, separate, directed laterally ; the lateral 

 process of the second cervical short, truncated. Ribs 16 . 16. 



3. Fhysalus Sibbaldii. 



Physalus (Rorqualus) Sibbaldii, Gray, P. Z. S. 1847, 92 ; Cat. Cetae. 

 43,;P.Z. 8. 1864, 222. fig. 15 a ; Ann. Hf Mag. N. H. 1864, xiv. 332. 



Inhab. North Sea, ascending rivers ; in the Humber, Yorkshire. 



Skeleton in Museum of the Hull Eoyal Institution and Literary 

 and Philosophical Society. Length 50 feet. 



The skeleton in the Hull Philosophical Society's Museum is 47 feet 

 long, and evidently of a young animal ; the arm or paddle is rather 

 more than 6 feet long. The baleen is all black. The lower jaw 

 strong, with a conical, large, well-developed ramus. Vertebrae 64: 

 cervical 7, dorsal 16, lumbar and caudal 41. Breast-bone wanting. 

 The cervical vertebrae are all separate ; the second cervical vertebra 

 has a broad lateral expansion, and is oblong, obliquely truncated 

 from the wide upper to the narrow lower edge, and with a small 

 oblong subcentral perforation near the base ; the third, fourth, fifth, 

 sixth, and seventh cervical vertebrae have a straight, rather elongate 

 lateral process, which projects straight out from the body of the 

 vertebra, and the upper and lower ones are of nearly equal length. 

 The ribs 16 . 16, all simple. The end of the first rib, near the ver- 

 tebra, has a single head ; and the head of the first and second rib is 

 compressed laterally, and with a slender internal process. The 

 articulating surfaces of the cervical vertebrae are oblong, transverse, 

 much broader than high. 



Fig. 36. 



Second and fifth pervical vertebras oi Physalus Sibhaldii. (From a sketch 

 by Mr. Harrison, of Hull.) 



