12 BULLETIN 73, UNITED STATES NATIONAL MUSEUM. 



No additional specimens have been recorded from European waters or else- 

 where, and much doubt has been thrown on the validitj^ of the species, many zoolo- 

 gists rcgardincr it as an adult of the commoner species M. hidens. Van Beneden 

 remarked in 18SS:» 



The opinions of naturalists are divided as regards the identity of this ziphioid, which is unique up 

 to the present time. In the eyes of some it represents an old male of the common Mcsoplodon, in which 

 the tooth, instead of developing near the middle of the jaw, has developed near the anterior extremity. 

 This is the opinion of Doctor FLscher and others, who think that this unique specimen represents merely 

 an indi\idual modification and that conse<iuently it should not figure in the list of species. We do not 

 share this opinion. It is not impo.ssible that this ziphioid may belong to the other hemisphere, and this 

 would explain why only one single individual has been captiu-ed in Europe." 



In view of the circumstances surrounding the discovery of the original specimen, 

 it is of great interest to find that two of the specimens from the east coast of the 

 United States represent the same species. As one of them is adult and the other 

 young, the view that the tj-pe of M. europseus is merely an old individual of M. Udens 

 is satisfactorily disposed of, as is also the opinion that it represents a singular 

 individual variation. 



The two American specimens which represent europseus are those from North 

 Long Branch, New Jersey (adult female; skull, lacking rostrum and mandible, in 

 the Museum of Comparative Zoology), and from Atlantic City, New Jersey (j'oung 

 male; skeleton, cast and photographs in the U. S. National Museum, Cat. No. 23346). 



SPECIFIC CHARACTERS. 



The species europseus differs from hidens in the fohowing characters, which may 

 be regarded as diagnostic: 



Size larger and pectoral limbs relatively shorter and narrower. 



The expanded portion of the maxilla and frontals broader in front of the orbit. 

 The protuberance which projects into the anteorbital notch much larger and the 

 ridge on the maxilla which extends backward from it much higher. Distance from 

 inner margin of maxillary foramen to tip of protuberance much more than one-half 

 the distance between the maxillaiy foramina of the two sides. Rostrum deeper at 

 the base. Inferior surface of pterygoids more or less convex, with a ridge (in adults) 

 runnmg diagonally across it. 



The cranial characters above enumerated are found in the tj'^je-skull, as will 

 be seen by examining the excellent figures in Van Beneden and Gervais' Osteography, 

 plate 24. 



In Dr. Glover M. Allen's account of the Long Branch specimen* it is stated 

 that the fishermen who measin-ed it reported that it was 22 feet long, while none of 

 the European specimens (some of which were certainly adults) was more than 16 J 

 feet long. That the measurement reported by the fishermen is at least approxi- 

 mately correct appears from the fact that the skull is larger than that of any of the 

 European specimens. The beak is missing, so that the total length of the skull can 

 not be given, but the distance from the occipital condyles to the Ime of the maxillary 



a Bull. Acad. Roy. Belgique, vol. 41, 1888, p. 117. 

 b Amer. Nat., vol. 40, 1906, p. 359. 



