494 PROF. FLOWER ON THE DELPHINID.E. [NoV. 20, 



bones. The cervical vertebrae have a greater tendency to ankylosis 

 than in other Dolphins, the first three being often united by their 

 bodies, and several of the others by their neural arches. This 

 disposition has not been observed in L. albirostris. The mauus also 

 has a more characteristically flattened and broad form than in L. albi- 

 rostris. 



Of the other species of Dolphins which have been assigned to this 

 group, the following are the most noteworthy : — 



Lagenorhynchus ijei-spicillatus, Cope (Proc, Acad. Nat. Sciences, 

 Philadelphia, 1876, p. 136), said to be abundant on the coast of 

 Maine (North Atlantic). This is apparently closely allied to, if not 

 identical with, L. acutus, as might naturally be supposed from its 

 habitat. Slight differences in the external colouring are pointed out, 

 and the teeth are said to be only ,^. A figure of the animal is 

 given. A more rigid examination both of the osteological and the 

 external characters of a series of specimens is required before its 

 specific distinction from L. acutus can be admitted. 



Lagenorhynchus obliquidens, Gill, from its remote habitat (the 

 North Pacific) might be expected to present greater differences ; but 

 if it does these have not yet been pointed out. It appears to be 

 closely allied to L. acutus, judging by Scammon's figure and de- 

 scription (Marine Mammals of N. America, p. 98). The description 

 of the skeleton by Dall, in the same work, is full of anatomical 

 details, but is without any discrimination as to characters common 

 to many other species, or such as may be peculiar to the individual 

 described, and does not even state the number of the vertebrae or 

 the ribs. 



Gervais's account of this genus is very confused. In enumerating 

 the species (p. 593) he speaks of L. eschrichtii from the North 

 Atlantic, jtiving as synonyms in the footnote L. eschrichtii, Sclilegel, 

 D. leucopleurus, Rasch, and 1). acutus, Gray. In describing the 

 skeleton he speaks of L. eschrichtii and L. leucopleurus as if they 

 were distinct species, pointing out, among other characters, that in 

 L. eschrichtii the six anterior ribs have heads, while in L. leuco- 

 pleurus only five are so provided. He speaks of Gray's L. asia, 

 but makes no mention of Gray's L. electra, which, being placed 

 first in the original description in the ' Zoology of the Erebus and 

 Terror,' should be taken as the type and name-giver, if the two are 

 considered as one, as even Gray appears to consider as probable. He 

 identifies Owen's D. fusiformis with Gray's L. clanculus. In the 

 plate devoted to the genus (tab. xxxvi.), L. albirostris (fig. 5) ap- 

 pears to be the same as Gray's; but the cranium and hinder part of 

 the maxilla are wider, perhaps because it is from a younger indivi- 

 dual. L. leucopleurus (fig. 4) is probably also taken from a young 

 individual. L. asia (fig. 6) is larger even than Gray's electra, though 

 the principal difference between the types of these supposed species 

 is that the former is somewhat smaller than the latter. L. cruciger 

 (fig. 3) is apparently Gray's clanculus ; if so the former name 

 should have the preference, provided any satisfactory identification 



