16 



MR. R. LYEEXKER OX THE CETACEA OF THE SUFFOLK CRAG-. 



in the Ipswich Museum. The periotic agrees very closely in structure 

 with a specimen of the corresponding bone of 0. gladiator in the 

 Museum of the College of Surgeons, and accords in relative size with 

 the tooth. As I am unable to distinguish the latter from the teeth of 

 the small Orca citoniensis, Capellini*, from the Pliocene of Italy, I am 

 disposed to refer the English form to that species. The next form for 

 consideration is that to which Prof.Lankesterf applied the name Bel- 

 phinus uncidens (the generic term being used in the Linnean sense), 

 with which D. orcoides of the same author may be united, since the 

 larger teeth to which the latter name was applied are merely the 

 hinder ones of the same species. Some confusion occurs in the 

 description of the larger teeth, since they are stated to agree in 

 size with those of Pseudorca and Orca t, whereas they really corre- 

 spond in this and other respects with those of Gfobicephaltts, to which 

 genus they may be referred. The evidence for this reference does 

 not, however, depend solely upon the teeth, since there is in the 

 British Museum a very beautiful associated left periotic and tym- 

 pauic from the Coralline Crag (the former bone being represented in 

 PI. II. fig. 11), which agree precisely in size with the corresponding 

 bones of 67. melas, and only present slight structural differences of 

 specific value. Polled periotics and tympanies of this type are of 

 extremely common occurrence in the Ped Crag, an example of the 

 former being represented in pi. viii. figs. 2, 3 of Prof. Lankester's 

 memoir. To render the foregoing evidence absolutely conclusive, the 

 British Museum possesses a lumbar vertebra (No. 28271) from the 

 Ped Crag which is undistinguisbable from the corresponding bone 

 of G. melas. There are several less perfect vertebras of the same 

 type in the latter collection, while some unnamed vertebras in the 

 Brussels Museum apparently indicate the occurrence of the same 

 species in the Antwerp Crag. The last form I have to notice is one 

 indicated by numerous periotics and tympanies in the British Museum 

 and other collections, which indicate a Dolphin agreeing in size with 

 the existing Lagenorliynchus acutus ; I have not, however, been able 

 to determine the genus of this type, which may include more than 

 one species, and may be identical with one or both of two Belgian 

 species to which Prof. Yan Beneden has applied the name of Bel- 

 jjhinus Wasii and B. Belannoyi (the generic term being used in a 

 wide sense). The specimens in the Brussels Museum do not. however, 

 include any examples of the periotic, so that I could not institute 

 any comparison between the Belgian and the English specimens. 



I may conclude this paper with a list of the well- authenticated § 

 species of Cetacea occurring in the Ped and Coralline Crag, those 

 species of which the identification is doubtful being indicated by a 

 query. 



* Mem. Ac. Sci. 1st. Bologna, ser. 4, vol. iv. p. 670 (1883). 

 t Ann. & Mag. Nat. Hist, ser. 3, vol. xiv. p. 356 (1864). 

 X Mentioned as species of Delphinus in Prof. Lankester's memoir. 

 | I omit a few forms which have been erroneously recorded from the Crag 

 or of which the description is too vague to admit of identification. 



