DELPHINAPTEKUS LEUCAS. 1 17 



Prior to the year 18G5 naturalists seemed to have been pretty well 

 agreed that there existed but one species of white whale, the "beluga," 

 " witlisch," or " weissfisch." We must except^jray and Desmarest, how- 

 ever, the former haviug erected 1). Kiiujii on a specimen supposed to 

 have come from New Holland, and the latter having- made a distinct 

 species of Duhamel's Dauphin blanc du Canada (Z>. canadensis). Of 

 these species more will be said subsequently. 



In ISG5 Professor Cope, having studied the material brought back 

 by Drs. Hayes aud Kane, divided the genus into three sections from 

 osteological characters, and assigned B. rldnodon and catodon to the 

 first, decUris to the second, and concrcta to the third. 



Upon examination of the diagnosis it appears that the same charac- 

 ters, thirty-six in number, are, with eight exceptions, repeated in two 

 or more species in different combinations. Thus rlihiodun and deeUvis 

 have the vomer well developed between the palatines, while concreta 

 has not. On the other hand decUvis and concreta have the beak one- 

 half the total length of the skull, but rldnodon wot. Uf five skeletons 

 in the British Museum and at Oxford none exhibit the same combina- 

 tion of characters exhibited by any of Professor Cope's species, nor did 

 any two agree together. Thus No. 3G7a (British Museum) has the 

 palatines barely in contact, a character peculiar to rhinodon, but it has 

 also the beak equally one-half the length of the skull, and the teeth 

 9-9, which is not the case in rJiinodon. No. 268a has three characters 

 of catodon, but has the muzzle less than one-half the length of the skull, 

 and the vomer well developed between the palatines, which is not the 

 case in catodon. 



It therefore appears that each of these five specimens must be re- 

 garded as the type of a new species, or the divisions of the original 

 species, D. leucas, must be broken down ; for the former course there is 

 apparently no warrant. 



Let us examine the characters themselves. The first character of 

 Professor Cope's sections relates to the cervical vertebra?. In section 

 a and aa those vertebne are separated, in aaa the axis and third verte- 

 bra are anchylosed together. It is doubtful whether this is anything 

 more than an individual variation. In a skeleton in the national col- 

 lection the third cervical is anchylosed to the axis on the left side, but 

 not on the right side; the area of attachment is small. In one of two 

 skeletons of X. acutus now on my tables, the first three cervicals are 

 united by the centra, and the first four by the spines, the remaining 

 cervicals being free; in tire second skeleton the first three cervicals are 

 united by the centra, and the first five by the spines, while the sixth 

 and seventh cervicals are also united together hy their neural arches 

 and spines. 



Such variations in the amount of anchylosis of the cervicals are of 

 frequent occurretice in this ando'her species of the BeJphinida', and cer- 

 tainly do not indicate specific diversity. The presence or absence of a 



