4 BULLETIN "3, UNITED STATES NATIONAL MUSEUM. 



specimens represent Mesoplodon europseus (Gervais) . This is a very interesting dis- 

 covery, because the latter species hi»s been known hitherto only from a single skull, 

 and its validity has been frequently questioned. The Annisquam specimen, as will 

 be seen later, presents characters which appear to ally it to M. densirostris. 



MESOPLODON BIDENS (Sowerbyj. 



Physeter hideiis Sowerby, British Miscell., 1804, p. 1; Trans, Linn. Sop. London, vol. 7, 1804, 



p. 310. 

 Ddphinm sowerbcnsis Blainville, Nouv. Diet. Hist. Nat., 2d e(l..vol. 9, 1817, p. 177. 

 Delphinus sowcrbyi Desmarest, Mammalogie, pt. 2, 1822, p. 521. 



The only specimen from the Atlantic coast of the United States which can 

 with certainty be referred to this species is the one from Nantucket mentioned on 

 page 3. Prof. L. Agassiz's original notice of it is so brief that it is quoted in full 

 below: 



Professor Agassiz also brought to the notice of the Society the discovery of a Cetacean, new to 

 America. The skull was exhibited, and its peculiar features pointed out. It was obtained on the 

 coast of Nantucket by Messrs. H. M. and S. C. Martin, of Roxbury. It belonged to thegenus Mesoplodon , 

 as characterized by Gervais, and ought to be separated from the fossil Ziphius, described by Cuvier. 

 Professor Agassiz, however, questioned whether Mesoplodon was not identical with Del phinorliynchus, 

 previously described by De Blainville. The specimen found at Nantucket measiu:ed 16 feet in length." 



The skull of this Nantucket specimen, which I have before me, is thoroughl_v 

 adidt. That the specimen is a female is probul)le from tlie fact that the teeth (one 

 of which is preserved), though fully developed, are only two-thirds as broad and 

 three-fourths as long as those of Sowerby's specimen (the type of the species), 

 which was an adult male.* The skull is 7G.5 nun. long, and about 30 mm. are lack- 

 ing from the end of the beak, so that the original length was about 795 mm. It 

 appears to be, therefore, rather the largest skull of the sj)ecies of which there is any 

 record. The specimen itself, according to Dr. J. A. Allen, was 16 feet 3 inches 

 long. "^ The largest European skidl appears to be the one in the Edinburgh Museum, 

 described by Sir William Turner in 1872.'' The length of this is 749 mm. The 

 specimen was a female, but though the skull is so large, the mesirostral cartilage was 

 not ossified, and the individual was, therefore, probabh' not thoroughly adult. 

 Two other European specimens, of which the total length was almost identical 

 with that of the Nantucket specimen, were (1) the adult female obtained at Over- 

 strand, England, in 1892, and recorded by Southwell and Harmer' (length 16 feet 



oProc. Boston Soc. Nat. Hist., vol. 11, 1866-68, p. 318. 



b One of the teeth of Sowerby's specimen is figured by Lankester in Trans. Roy. Micr. Soc, new 

 ser., vol. 15, 18G7, pi. 5, figs. 1, 2. 



cBull. Mus. Comp. Zool., vol. 1, 1869, p. 205. 



<i Trans. Roy. Soc. Edinburgh, vol. 26, 1872, p. 771. 



« Zoologist, eer. 3, vol. 17, Feb., 1893, p. 42; Ann. and Mag. Nat. Hist., ser. 6, vol. 11. 1893, p. 275. 



