140 BULLETIN 30, UNITED STATES NATIONAL MUSEUM. 



Ft. In. 



Flukes from tip to tip ;5 lu 



Length of mouth 1 3^ 



Length of eye H 



Length of canclal ridge extending upward from notch of llukes 4 4 



Vertical height 3 



Greatest width of caudal region at a distance of 3 feet 1 inch from notch of 



flakes 2 3 



The vertebral formula iii this specimen aud iu the 18 foot skeleton 

 from Florida is as follows: 



Male. Dam Neck Mills, Va. C. 7 ; D. 11 ; L. 11 ; Ca. 28 =.57. 

 Sex ? Osprey, Fla. C. 7 ; D. 10 ; L. 12 ; Ca. 26 (?+2) = 5.5 or 57. 



Measurements of the skulls of all the specimens will be fonnd in the 

 table on page 142. 



The color in every case was entirely black, and the premaxilhne cover 

 the maxilhe in the distal half of the beak. 



On comparing the skulls of these specimens with that of G. scammoni 

 (No. 9074) numerous differences were found which made it apparent that 

 G. hrachypterus and G. scammoni could not be regarded as specifically 

 identical. In G. hrachypternfi the intermaxilhTP project beyond the free 

 margin of the maxillte, which margin is quite deeply grooved. In G. 

 scammonij on the contrary, the intermaxilise do not extend quite to the 

 margin of the maxilla\ This difference in the disposition of parts can 

 not be regarded as an age character, since the skull of G. scammoni is 

 the older. 



In G. scammoni, again, the greatest enlargement of the intermaxillas 

 occurs at the junction of the proximal and second fourths of the dis. 

 tance from the maxillary notch to the extremity of the beak, while in 

 G. hrachypterus the length from the maxillary notch to the point of 

 greatest enlargement of the premaxilla? is contained only abuut two and 

 a half times in the length of the beak. 



The rugosities near the distal extremity of the premaxilhe are very 

 strongly marked in the skull of G. scammoni, but only slightly in any 

 of the skulls of G. hrachypterus. As the largest skull of the latter 

 species is certainly from an adult animal it is improbable that this dif- 

 ference is entirely due to age. 



In both the older and younger skulls of G. hrachypterus the nasal 

 septum is ossified so as to stand above the plane of the adjacent inter- 

 maxillae, which is not the case in G. scammoni. 



The skulls of G. hrachypterus are also distinguished from that of G. 

 scammoni in having the beak longer and narrower, the blowhole nar- 

 rower and placed further oack, the width at the orbits greater and the 

 temporal fossae considerably larger. 



The external characters considered by Professor Cope to be diagnos- 

 tic of G. hrachypterus are (1) the length of the pectoral fin, and (2) the 

 anterior position of the dorsal fin. 



As regards the length of the ])ectoral fin, I find by comparing the 



