20 PROCEEDINGS OF THE ACADEMY OF 



fin and character of the dorsal line ; it is marked, and of a kind which Lillje- 

 borg has regarded as generic in the case of S. gig as (S. b o r e al i s), but 

 which appears to me to be specific in this case. This species is distinctly 

 smaller than the S. t e c t i r o s t r i s, and presents a tuberculum atlantis articu- 

 lating with the epistrophseus below, which is not indicated by the latter in S. 

 tectirostris. 



In many respects the species appear to be quite similar. The deposit of the 

 specimen of S. t u b e r o s u s in the Museum of the Academy having been de- 

 layed, the nearer comparison must be made when it arrives, which will be in a 

 short time, it is anticipated. 



As compared with the S. g i g a s there is a marked difference in the form 

 of the nasal bones, if Dubar is to be relied on ; he represents them as even 

 more elongate than in the S. 1 a t i c e p s. The first rib of this animal is appa- 

 rently much wider. The annulate cervicals are less numerous. The dorsal 

 fin has a different form and position. 



The type of the S. tectirostris came ashore duringthe winter of the present 

 year, on the coast near Sinepuxent Bay, on the Maryland peninsula. It had 

 been dead some time ; the stomach contained bflt little, and that a mixture of 

 finely divided scaly and stringy material, not readily recognizable. Bottles 

 dropped at numerous points off the coast of Maryland and Virginia by the 

 Coast Survey, were always carried ashore in the caurse of a few days or weeks, 

 to the south-west of the point where dropped. It is therefore probable that 

 this whale is a native of the ocean from which it drifted, and that it is one of 

 the " fin-backs " of the Western Atlantic. 



The species described by Capt. Scammon, if of this genus, belongs to the 

 sub-group of the S. bo re alls, so far as the proportions and position of 

 the dorsal fin are concerned ; the cervical vertebrae are not yet known. Its 

 size would also distinguish it from the species of the other groups, as well as 

 from the S. s c h 1 e ge 1 i i Flower, from the Malaysian Seas. 



SiBBALDIUS SDLFUREU3 CopC. 



The Sulphur-Bottom of the North West Coast. 



This immense whale is as yet too insufficiently known to be distinguished as 

 fully as desirable, but the marked peculiarity of coloratjion separates it from 

 the only species with which a comparison is necessary — the S. b o r e a 1 i s or 

 gigas of the North Atlantic. Capt. Scammon describes it to be a gray or 

 brown above, paler than in the Balaenoptera v e 1 i f e r a, and beneath, a sul- 

 phur yellow. Length from seventy to ninety feet.,. The colors of the S. b o- 

 realis are described as polished black above, milky white beneath, by 

 Dubar. 



DENTICETE. 



Three f;imilies of this order are known, which differ as follows, according to 

 Flower : 



Costal cartilages not ossified. The hinder ribs losing their tubercle and 

 retaining their capitular articulation with the vertebrae. The greater number 

 of the cervical vertebrae ancylosed together. Pterygoid bones thick, produced 

 backwards, meeting in the middle line, and not involuted to form the outer 

 wall of the postpalatine air-sinus Physeteridae. 



Costal cartilages not ossified. The tubercular and capitular articulations of 

 the ribs blending together posteriorly. Cervical vertebrae all free. Pterj-goid 

 bones thin, not conforming in their mode of arrangement with cither of the 

 other sections , Platanistidae. 



Costal cartilages firmly ossified. Posterior ribs losing their capitular articu- 

 lation, and only uniting with the transverse processes of the vertebrae by the 

 tubercle. Anterior (2 — (5) cervical, in most, ancylosed together. Pterygoid 

 bones short, thin involute, to form, with a process with the palatine bone, the 

 outer wall of the postpalatine air-sinus Delijliinidne. 



[April, 



