610 PIIOCA FCETIDA HINGED SEAL. 



The Baikal Seal was specifically distinguished much later, it 

 having been referred even by Badde, as late as 1862, to Phoca 

 annellata (=fcetida). Although it was recognized varietally by 

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

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

 separated as a species by Dy bow ski in 1873,* under the name 

 Phoca baicalensis. 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 should 

 not be referred to "Phoca annellata^ it being easy to distinguish 

 from it at all stages. Dybowski 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- 

 parative 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 Phoca fwtida, 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 fos the length and nar- 

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

 for while its length is the same as in aver age 'skulls of P. fcetida, 

 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 



tiou, however, of the young, which, inexperienced as they are, follow the 

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

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

 Seals lying on their hack, sleeping peaceably while being rocked by the waves, 

 and throwing up from time to time small jets of water by breathing."* 



It further appears from the author's detailed account of Seal-hunting in tlu> 

 Caspian Sea (see anted, pp. 514-517) that these animals 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 

 halrits the Caspian Seal thus differs notably from the Ringed Seal, which 

 never resorts to the land in vast herds. 

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



* Archiv fur Anatomie, Physiologie und Weissenschaftliche Medicin, Jahr- 

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



