No. 2007. DESCRIPTION OF MESOPLODON MIRUM—TRUE. 653 



teeth was characteristic of the female of that species, but both sexes 

 of the latter are known, and both have the teeth near the posterior 

 end of the symphysis. There seems to be sufficient reason, therefore, 

 to regard the Beaufort specimen as representing a new species. It 

 was therefore described under the name of 



MESOPLODON MIRUM True. 

 Mesoplodon minim Tkue, Smiths. Misc. Coll., vol. 60, No. 25, p. 1, March 14, 1913. 



Tyi^e-locality. — Bird Island Shoal, Beaufort Harbor, North Caro- 

 lina. 



Type-sfedmen. — Cat. No. 175019, U.S.N.M. A skull with man- 

 dible and partial skeleton from an adult female 16 feet long which 

 stranded in Beaufort Harbor, North Carolina, July 26, 1912. 

 Obtained by the United States Bureau of Fisheries Laboratory, Mr. 

 Lewis Radcliffe, director. 



Diagnosis. — Teeth at the extremity of the mandible, small, entirely 

 concealed by the integuments (in the adult female). Mandibular 

 symphysis one-fourth the length of the mandible. No basirostral 

 groove. External free border of the lachrymal bone one-half the 

 length of the orbit; its anterior end curved upward and appearing 

 on the superior surface of the skull where it joins the antero-external 

 angle of the frontal plate of the maxilla. Maxillary prominences 

 short and directed obliquely outward anteriorly, the extremity close 

 to the maxUlary notch. IMaxillary foramina behind the premaxillary 

 foramina. Frontal plates of the maxillae approximately one-half as 

 broad as long. 



SKULL. 



Plates 54-56. 



Superior aspect. — Apex of the supraoccipital at the vertex rounded, 

 extending forward about one-half as far as the recurved internal 

 borders of the frontal plates of the maxillae. The frontals form an 

 irregular area of small extent at the vertex. Nasals elongated, wedge- 

 shaped, with the truncated apices directed forward. Frontal plates 

 of maxillae about half as broad as long, thek supero-internal recurved 

 borders behmd the proximal ends of the premaxillae directed out- 

 ward, rather than forward or backward. Proximal ends of pre- 

 maxillas short and thick, directed outward; portion at the sides of 

 and in front of the nares as in M. europseus. Maxillary prominences 

 large, short, and directed obliquely outward rather than forward as 

 in M. europseus. On account of their relatively slight projection 

 anteriorly, their apices are not as far from the bases of the anteorbital 

 notches as in 21. europseus, M. Jiectori, etc. The base of the notches 

 is occupied by the maxilla, malar and lachrymal in about equal pro- 

 portions. External free border ol the rostrum strongly emarginate at 

 the proximal end but straight more anteriorly, the beak tapering 



