186 UALiENOPTERIDiE. 



Proc. Zool. Soc. 1804, p. 208). The cranium is now in an extremely 

 imperfect condition, the maxillaries, premaxillaries, and nasals being 

 absent. There is, however, enough to show that it is not a Mega- 

 ptera, but belongs to the subfomily Balcenopterince, and probably, on 

 account of the great width of the external part of the orbital process 

 of the frontal bone, to the genus SihhaJdins. The lower jaw is 52" 

 long, wliich would indicate an animal of about 18 feet, perhaps a 

 young individual of the species last described." — Floiver, P. Z. S. 

 1864, 408. 



III. Dorsal Jin high, erect, compressed, falcate, about tivo-thirds of the 

 entire length from the 7tose. Pectoral moderate, with 4 short JingerSf 

 of 4: or G Joints. Vertehrce 50. Cervical vertebrce sometimes aiich)/- 

 losed. Neural canal hroad, trigonal, broader than high. Hibs 11 . 11. 

 Balteuopterina, or Beaked Whales. 



8. BAL^NOPTERA. 



Ralfenoptera, Sect. 1 (Balajnoptera), Gi'at/, Zool. Ereb. ^ Terr. 50. 

 Balfenoptera, Gray, P. Z. S. 1847, 89 ; Cat. Cetac. B. 31. 1850, ;}1 ; 



P. Z. S. 1864, 226; Ann. Sf Mag. N. Jf. 1804, xiv. 352; Fkncer, 



P. Z. S. 1864, 393. 

 Balfenoptera (pars), Laccpede, Cetac. 



Pterobalpena (pars), Eschricht, JVord. Wallthiere, 1849, fol. 

 Balsena (pars), Linn. ; Midler, Zool, Dan. ; Illiger, Prodr. 242. 

 Rorqualus, sp., Dekay ; F. Cuvier, Cetac. 321. 

 Balseua minimus, Knox, Cat. Whale, 14. 



. nead elongate, flattened, throat and chest with deep longitudinal 

 folds and very dilatile. The dorsal fins compressed, falcate, two- 

 thirds the length of the body from the nose and behind the line 

 above the orifices of generation. The i^ectoral fins moderate, one- 

 eighth the length of the body, one-third the length of the body from 

 the head, witli 4 short fingers of few joints. The humerus short, thick. 

 The radius nearly twice as long as the humerus. Lower jaw-bone 

 moderate, with a distinct high conical coronoid process. Vertebra? 50 ; 

 last very smaU. The first pair of ribs undivided near the condyle. 



The lateral process of the second cer\acal vertebra elongate, pierced 

 at the base ; of the third, fourth, and fifth cervical elongate, slender, 

 separate ; the lower with an angidar bend below. The front ribs 

 simple, thick, with only a slight swelling on the inner edge near 

 the condyle. Tympanic bones obovate, short, ventricose. 



The lateral process of the second corneal vertebra expanded, broad, 

 with a large ovate perforation in the middle of its base, the upjier 

 and lower margins being broad and of nearly equal width, the upper 

 being, if anything, rather the broader of the two, very unlike the 

 lateral process of the same bone in Phijsahts. The neiiral arch high, 

 acute, with a rather high subcircular canal for the spinal marrow. 

 The l)ody of the atlas vertebra oblong, transverse, with a subcylin- 

 drieal lateral process produced from the middle of the side. 



" Total number of vertebnt) 48-50. llibs 11 pairs. Orbital pro- 

 cess of frontal almost as broad at the outer end as the base. Nasal 

 bones rather narrow and elongate, truncated at their anterior ends. 



