TECHNICAL HISTORY SPECIES. 421 



Jlistriophocaj Pusa, Monaclius, Cystophora, Macrorliinus, Lobodon, 

 Ogmorhinus, Leptonychotes, and Ommatophoca. Wliile Dr. Gill 

 recognized the same number of genera in 1877 as in 1866, the 

 nomenclature is quite different ; but this is due mainly to simply 

 changes of names, as the substitution of Pnsa for Halicliccrus, 

 of Ogmorhinus for Stenorhynchus, and of Leptonychotes for Lcp- 

 tomjx ; but in the later enumeration 'Pagomys is omitted and His- 

 triophoca is added. 



So far as the number of genera is concerned, the .greatest differ- 

 ence of opinion has always obtained in respect to the Piloting 

 all the members of which group are confined to the Northern 

 Hemisphere. Gray, after 1804 (1864-1874), uniformly recog- 

 nized seven ; Gill, 186G-1S77, six, only two of which (Haliclm- 

 ruft and Nonachus, about which authors generally have for many 

 years been in unison) were the exact equivalents of Gray's 

 genera; but the chief disagreement consisted in Gill's use of 

 Phoca for what Gray termed Callocephalus, and of Erignatlius for 

 what Gray termed PJioca. Lilljeborg*, in 1874, referred all of 

 the species of the Phoeina', except Haliclicerus grypns (and Mo- 

 nacJttts albiv enter ) which latter is not there treated), to the genus 

 Phoca, and von Heugliu the same year did the same, except that 

 Pagomys, Pagophilus, and CaUoceplialus (the latter being applied 

 to C. barbata) were recognized as subgenera under Phoca. The 

 classification and nomenclature of Giebel (1855), Blasius (1857), 

 Malmgren (1863), and Holmgren (1865) are, generically, the 

 same as Lilljeborg's in 1874. The tendency has, in short, been 

 to refer all the species of Pliocin(v, with the two exceptions al- 

 ready specified, to the Linnrean genus Phoca. 



SPECIES. Although Seals have figured in works on natural 

 history since the time of Eondelet, Olaus Magnus, and Gesner 

 (1554-1555), it is unnecessary in the present connection to refer 

 in detail to those earlier works, since down to the time of Steller 

 (1751), all the Phocids* or Earless Seals known to systematic 

 writers were referred to the common Seal (Phoca vitulina, auct.) 

 of the shores of Middle and Northern Europe. This indeed was 

 the only species recognized by Linue, from the Northern Hem- 

 isphere, even in the last (1766) edition .of his "Systema Naturae." 

 But other species had been incidentally and vaguely described 

 by the early Greenland missionaries, and by explorers and trav- 

 ellers in both the Arctic and Antarctic regions, to which refer- 



a Sveriges och Norgos Ryggradsdjnr, i, Daggdjnren, pp. 667-729. 



