48 AGArnELmac. 



anterior caudal vertebrae ; they are of a much more elongate form 

 than any I have seen or found figured, excepting those of the Balce- 

 noptera rostrata (as figured by Gaimard in ' Voyage de la Recherche'), 

 which, however, are relatively shorter. Those of the present species 

 are of greater length than transverse diameter, the lumbars most 

 elongate ; all furnished with an acute hypapophysial keel and con- 

 cave sides, and entirely transverse diapophyses. This peculiarity is 

 consistent with the account of my informant, who stated the animal 

 to have been of an unusually elongate and slender form. When it 

 came ashore it had perhaps been dead ten days ; the flukes and 

 muscular region as far as the third caudal vertebra had been de- 

 voured, probably by Sharks and Killers, and the abdominal region 

 much lacerated ; the edge of a fin preserved was slit by the teeth of 

 some carnivorous enemy. The measurement from the end of the 

 muzzle to the end of the third caudal was 35 feet, which may be 

 reduced to 33 feet axial. Up to this point the dorsal line was, ac- 

 cording to my informant, entirely smooth, without knob or fin, or 

 scar of one ; hence I suppose the fin (if present) to have been situ- 

 ated, as in Sibbaldius &c, at the posterior fourth of the length, and 

 not, as in Balcenoptera, on the posterior third. It may then be safely 

 assumed, bearing in mind the form of vertebrae, that ten feet of the 

 whale's length had been removed, making in all 43 feet. That the 

 species attains over 50 feet is probable, as the present individual 

 was quite young, the epiphyses separating from the vertebrae with 

 the greatest ease. The slender form of the animal is corroborated 

 by the slenderness and slight curvature of the ribs, one attached 

 beneath the scapula, probably the second, being narrower than the 

 corresponding ones in Sibbaldius. I therefore think it most probable 

 that in this form the anterior ribs are single-headed." — Cope, I. c. 

 p. 223. 



1. Agaphelus gibbosus. The Scrag Whale. 



Agapkelus gibbosus, Cope. 



Balaana gibbosa, Gray, Cat. Seals §■ Whales, p. 90. 



Scrag Whale, Dudley, Phil. Trans, xxxiii. p. 259. 



Inhab. North Atlantic. 



2. RHACHIANECTES. 



Rhachianectes, Cope, Proc. Acad. N. So. Philad. 1809, pp. 14 & 15. 



Cervical vertebrae free. Throat without plaits. Dorsal fin 

 none. Scapula without acromion. 



1. Rhachianectes glaucus. The Calif omian Grey Whale. 



Rhachianectes glaucus, Cope, Proc. Acad. N. Sc. Philad. 1809, pp. 17 



& 40, fig. 8. 

 Agaphelus glaucus, Cope, ibid. 1808, p. 225. 



Inhab. California, San Francisco. 



"The points in which this species differs from those of the genus 

 Balaam previously known are numerous, and will no doubt be in- 

 creased on a further knowledge of the animal. 



