838 PROCEEDI.XfrS OF THE NATIONAL MUSEUM. 



groove is shallow and but little Gwry^di {onduUe). The external face 

 of the ridge is concave as far as the neck. The entepicondylar fora- 

 men is perfect. The internal tuberosity is raised into a thin ridge 

 toward the posterior face.''" 



These two species, while the}' present certain similarities, as indi- 

 cated by the tigures pul)lished by Yaw Beneden/' seem to me to ditfer 

 in so many details, at least as regards the humerus, that they can hardly 

 be considered as belonging in the same genus. The principal resem- 

 blance between them is in the flatness of the inner face of the deltoid 

 ridge, or, in other words, the shallowness of the bicipital groove. On 

 the other hand, the two forms, aside from marked disparity' in size, 

 present numerous difi'erences. In P. rousseaid the humerus is very 

 massive and the protile of the shaft has nearly the same concavity on 

 the two sides, while in P. )>ro.r!iiia the humerus is slender and the 

 external protile of the shaft nearly straight, and the internal protile is 

 strongly concave. Again, the posterior protile of the shaft is concave 

 in P. rortsseav! and straight in P. pro.rlind. In the former the free 

 margin of the deltoid ridge is thick throughout and bends down grad- 

 ually to the general surface of the shaft distally, while in ]\ pro.rliiia 

 it is thick in upper poi'tion. but diminishes suddenly in breadth at 

 about the middle of its length, forming a distinct thin edge distally. 

 Its distal termination joins the shaft at a sharp angle. The lower por- 

 tion of the humerus of P. rouxs-rtan' is wanting, and it is not known, 

 therefore, whether there is an entepicondylar foramen in this species. 



On account of the difl'erences above mentioned, I am inclined to con- 

 sider P. roiissea in' as the type and only species of the genus Pruphoca. 

 P. jtroxiiiKt^ as far as may ])e judg(»d from A an Beneden's tigures, pre- 

 sents the peculiar feature of a thin-edged deltoid ridge, nuich as in 

 Leptophoca^ l)ut as it difl'ei-s in that the shaft of the humerus is 

 straighter and that the concavity below the neck on the posterior face 

 of the shaft is lacking, I am uncertain as to whether it should be 

 referred to that genus. It is a little larger than L. len'ix. 



A considerable number of other species of European fossil seals 

 have been described more or less fully by various authors. The 

 majority of these are not comparable with Leptopliova^ having been 

 founded on teeth or on hones belonging to parts of the skeleton difier- 

 ent from those on which Lcjdophoca is based. Of the two or three in 

 which the humems is known, the form from Bessaral>ia described and 

 figured by T-Ordmann in I860 undei'the name of Pliord inneot'x'd*' shows 

 a close aHinity to LrptojiJuicti. The humi^rus is almost of equal size, 

 and in its genei'al form and characters and in many details, as judged 



"PrJ. Van Beiiedi'ii, Description des Ossements Fossiles des environs d' An vers, 

 Ire Partie, Pinnipe<les oa Aniphithcrioiis, Ann. Mns. Roy. d'Hist. Nat. Belg., I, 

 1877, texte et j)lanches, p. 80. 



''Idem, J)], .wui. 



'A. Nordniann, Paleontologie Sudri'isslands, IV, ISliO, i)p. JHH and ;>17, pi. .win, 

 figs. 1, 2. 



