610 rilOCA FCETIDxV PtlXGED SEAL. 



The Baikal Eeal was specifically distinguisbed mucli later, it 

 having- been referred even by Radde, as late as 18G2, to Phoca 

 imneUata {=foeticla). xilthough it was recognized varietally by 

 Erxleben and Grmelin a century ago, and the question of its spe- 

 cific distinctness raised by ISTilsson in 1837, it was first formally 

 separated as a species by Dybowski in 1873,* under the name 

 Flioca haicalensis. From three years' observation of the living 

 animal, and from study of the skulls of young and full-grown 

 animals, he reached the conclusion that the Baikal Seal shoukl 

 not be referred to '^Plioca annellata,''^ it being easy to distinguish 

 from it at all stages. Dybovvski has given excellent figures of 

 the skull, and detailed descriptions of its cranial and external 

 characters, and of its habits, but, unfortunately, makes no com- 

 13arative references to any other species, nor does he state ex- 

 plicitly in what its distinctive specific characters consist. His 

 very detailed table of measurements, and excellent figures of 

 the skull, however, when compared with P/iora/cefif/rt, leave no 

 reason to doubt the specific distinctness of the Baikal Seal from 

 that species. The skull of the Baikal Seal is especially remarka- 

 ble for its attenuation, and particularly for the length and nar- 

 rowness of the facial portion. Even the brain-case is narrow, 

 for while its length is the same as in average skulls of P. foetida, 

 its width is less. The orbital fossae are disproportionately large, 

 whence results a great lateral expansion of the rather slender 

 zygomatic arches, so that the breadth of the skull at the orbits 

 is considerably greater than at the mastoid processes (as 100 to 

 87), instead of these two dimensions being about equal, as in P. 

 fcetida. Dybowski gives the average length of two adult skulls 



tioii, however, of the young, which, inexj^erieuced as they are, follow the 

 lishiug-boats for long distances, and seem to take special pleasure in hearing 

 the lishermen whistle or sing It is an interesting spectacle to see the young 

 Seals lying on their back, sleepingpeaceahly while being rocked by the waves, 

 and throwing uj) from time to time small jets of water by bi'cathing."* 



It further axji>ears from the author's detailed account of Seal-hunting iu the 

 Caspian Sea (see antea, pp. 514-517) that these anim.als are preeminently 

 gregarious, and resort, at certain seasons, to favorite localities on the shore 

 in immense herds, to bask in the sun. The pairing season occurs about the 

 beginning of January, and the young are brought forth on the ice. In 

 habits the Caspian Seal thus difters notably from the Ringed Seal, which 

 never resorts to the land iu vast herds. 



"As translated in Rep. U. S. Com. Tish and Fisheries, pt. iii, 1873-4 and 1874-5, pp. 92, 93. 

 * Archiv fiir Anatomic, Physiologic uud Weisseuschaftliche Medicin, Jahr- 

 gang 1873, pp. 109-125, pi. ii, iii. 



