OF THE NOKFOLK " FOKEST-BED." 321 



This concavity is such that the intervertebral foramina are raised 

 much above the level of the floor of the neural canal, and this is not 

 the case in the fossil. Even in this particular, however, there is 

 some difi^erence among the recent examples ; but in none of them is 

 the upper surface so flat as it is in the fossil. 



In the Cetacean Gallery of the British Museum, South Kensington, 

 there is a specimen of the cervical vertebra) of a JBalcena, labelled 

 B. hiscayensis (no. 338, /.), which has the upper surfaces of the 

 vertebrae more flattened, and therefore agrees better with this 

 fossil. There is one important point, however, in which this, as well 

 as the B. mi/sticetus, differs from this fossil, and that is in the pro- 

 portion between the width across the cups of the atlas and the 

 length of the vertebral centra measured along their lower surfaces, 

 as shown in the table of measurements on page 320. 



The British-Museum specimen, which was dredged off Selsej, was 

 referred by Dr. Gray at first to Balcena hiscayensis, but afterwards 

 to a new species, and subsequently to a new genus (Proc. Zool. Soc. 

 1873, p. 140). In the latest catalogue of the British-Museum 

 Cetacea (by Prof. Flower, 1885) this specimen, in the absence of 

 sufficient evidence for separation, is included provisionally under 

 the name of Balcena austixdis. 



By some authors B. hiscayensis^ B. australis, and B. antipodarum 

 are regarded as distinct sf)ecies ; but their cervical vertebrae, 

 as figured by Gervais and Van Beneden (Osteographie des Cetaces, 

 pis. i,, iii., and x.), do not show differences which can be taken as 

 definitely specific. 



The fossil forms of Balama, Bala^nula, and Balcenotus described by 

 Van Beneden (" Ossem. Foss. d'Anvers," Ann. Mus. E-oy. Hist. Nat. 

 Belg. tome iv. part 2, 1880) may have some resemblance to the 

 *' Forest-bed " fossil, but are less nearly allied to it than some of the 

 recent forms. 



Mr. Backhouse's specimen is certainly a Bakena, and possibly may 

 represent a new species ; but bearing in mind the uncertainty which 

 exists as to the living species of the genus, it is better not to give a 

 new name, but to refer the fossil provisionally to one of the recent 

 species. It is generally agreed that in the northern hemisphere 

 there are two true whalebone Whales — one the Balcena mysticetiis, 

 which is only found in high northern latitudes and always in the 

 neighbourhood of ice ; the other, which has been named B. hiscay- 

 ensis, is believed to be the form that, until quite modern times, was 

 an inhabitant of our own seas. At present there is some doubt as 

 to the southern species, B. australis and B. antipoclarum, being 

 distinct from B. hiscayensis ; but their identity has yet to be 

 established. Balcp-na mysticetus may, like some other northern 

 mammals, have found its way further south in later Pliocene times 

 than it does at the present day, and it is just possible that this 

 fossil might belong to that species ; but the available evidence seems 

 rather to favour its being referred provisionally to B. hiscayensis. 



In the Survey Memoir on the " Forest-bed " Vertebrata two large 

 Cetacean vertebra) were noticed; but in the absence of sufficient 



