142 



THE WHALEBONE WHALES OF THE WESTERN NORTH ATLANTIC. 



16045 from Cape Cod, Mass. (See pi. 7, fig. 4.) The Cayeux specimen, cited by 

 Fischer as young, appears to be exceptional in having the anterior border entire, 

 with a vacuity below it, and the stem and wings scarcely differentiated. A close 

 approximation to the normal form of the immature sternum is perpetuated in the 

 adult in Malm's Finmark specimen, and Sars's Christiania Museum specimen. The 

 latter leads to the more extraordinary adult form exhibited by the Groix Id., Albany 

 (N. Y.) museum, Rochester (N. Y.) museum, and Langrune specimens, in which 

 the anterior emargination is generally pronounced and the wings long and pointed. 

 A quite different adult form is shown in the Vlieland Id., Herault, Borselaer 

 (Schelde R.), Bayonne, and Cambridge (Mass.) museum specimens, in which the 

 anterior border is convex, forming a fourth projection and converting the trefoil 

 into a quatrefoil. This is carried to an extreme in Struthers's Peterhead specimen, 

 in which the stem is aborted, and in the St. Cyprien specimen, in which the anterior 

 portion is very large, with a straight margin and a vacuity within it. Finally, we 

 have a variation in which the anterior and lateral limbs are merged together, as 

 shown in the Falmouth and Cambridge (Mass.) museum specimens. 



In all these variations the American specimens run parallel with the European 



ones. 



FIG. 33. 



FIG. 35. 



FIG. 34. FIG. 36. 



SCAPULA OF BALMNOPTERA PHYSALUS (L.). AMERICAN AND EUROPEAN. 



FIG. 33. LOFOTEN IDS., NORWAY. JR. (FROM SARS.) FIG. 34. SINEPUXENT BAY, MARYLAND. IM. S 

 TYPE OF B. tectiroslris (COPE). FIG. 35. CAPE COD, MASS. IM. No. 16039 U. S. N. M. FIG. 36. CAPE COD, 

 MASS. IM. No. 16045 U. S. N. M. 



PECTOKAL LIMBS. 



The figures of the scapula of B. physalus published by Malm (65, pi. 3, fig. 

 5) and Fischer (44, pi. 2, fig. 4) show the superior, or spinal, border quite evenly 

 convex and the acromion low. These are probably incorrect, as Menge's photo- 



