140 BULLETIN 36, UNITED STATES NATIONAL MUSEUM. 



Ft. In. 



Flakes fioui tip to tip ;i lu 



Length of mouth 1 3^ 



Length of eye H 



Length of candal ridge extending upwju'd from notch of flukes 4 4 



Vertical height 3 



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



flukes 2 3 



The vertebral formula iu this specimen and in 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) = 55 or 57. 



Measurements of the skulls of all tlie specimens will be found i!i the 

 table on page 142. 



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

 the maxillai in the distal half of the beak. 



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

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

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

 identical. In G. hrachypterus the intermaxillte project beyond the free 

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

 scammoni, on the contrary, the intermaxilla? do not extend quite to the 

 margin of the maxilhiB. 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 intermaxilla? 

 occurs at the junction of the jiroximal 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 premaxillai is contained only about two and 

 a half times in the length of the beak. 



The rugosities near the distal extremity of the premaxilla} 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 ])lane of the adjacent inter- 

 maxillii;, which is not the case in G. scammoni. 



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

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

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

 temporal fossoj 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 pectoral fin, I find by comparing the 



