272 CETACEA 



one-fourth the length of the ramus ; other cranial characters as in 

 the preceding genus. Teeth fi to \% of comparatively large size 

 (5-6 mm. in diameter) ; surface of their crowns finely grooved. 

 Vertebrae: C 7, D12, L 15, C 32 ; total 66. Represented by 

 S. rost rati is, from Avhich the forms which have received other names 

 are probably not specifically separable. 



Sotalia. 1 — Pterygoids narrow, not meeting in the middle line, 

 and in their inner borders diverging posteriorly, instead of being 

 parallel as in the preceding genera ; other cranial characters much 

 as in Stem. Teeth tolerably large (4-5 mm. in diameter), f £ to f 4, 

 with smooth enamelled surface. Vertebra? : C 7, D 12, L 10-14, 

 C 22 : total 51-55. Pectoral fin broad at base, the breadth being 

 caused by the considerable development and position of the two 

 outer digits. Six species are provisionally recognised as distinct, 

 including the Chinese White Dolphin (S. sinensis) and S. pallidus 

 from the river Amazon. 



Bibliography of Cetacea. — D. F. Eschriclit, U titer suchungcn iiber die Nordischen 

 WaUthicre, 1849, contains a copious bibliography of the group up to the date of 

 publication. Since that time numerous monographs on special families and 

 genera have been published, and a large illustrated general work, Osteographic des 

 Cetaces, by P. J. Van Beneden and P. Gervais, 1869-80. Besides those already 

 referred to in the footnotes, the following may be mentioned ; viz. J. F. Brandt, 

 " Untersuchungen iiber die Fossilen und Subfossilen Cetaceen Europa's," in 

 Jit oi. de V Acad. Imp. de St. Petersbourg, 7 iime ser. vol. xx. 1873 ; C. M. Scammon, 

 Murine Mammals of the N. W. Coast of North America, 1874 ; W. H. Flower, 

 " On the characters and Divisions of the Families of the Delphinidce" Proc. Zool. 

 Soc. 1SS3, p. 466, and List of the Specimens of Cetacea iii tin- British Museum, 

 1885 ; F. W.Tnie, " Review of the Family Delphinida;, " Bull. U.S. Nat. Museum, 

 Xo. 36, 1SS9 ; P. J. A r an Beneden, Histoire Naturclle des Cetacts des Mers 

 d'Europe, 18S9. 



For fossil forms, in addition to the works of Van Beneden, Gervais, and Brandt, 

 already cited, the reader may refer to various memoirs published by the former 

 writer in the Bull. Ac. P. Belgique and Ann. Mus. P. Hist. Nat. Brig. 

 See also R. Lydekker, " The Cetacea of the Suffolk Crag," Quart. Jour a. Oral. 

 Soc. vol. xlii. p. 7 (1887), and Catalogue of the Fossil Mammalia in the British 

 Museum, pt. v. (18S7). 



1 Gray, Cat. Seals and Whales Brit. Mus. 2d ed. p. 393 (1866). 



