THE "GENUS PUSA" OF SCOPOLI. 683 



Halichcerus forms (except possibly Monachus} the most strongly 

 marked generic type among the Piloting and in view of the 

 striking peculiarities of the skull it is not surprising that Dr. J. 

 E. Gray should have allotted it a subfamily (or "tribal") rank,* 

 but why he should have associated it with the Walrusses seems 

 hard to conceive. While the dental formula is the same as in the 

 other genera of Phocincc, the teeth depart widely in their simple 

 conical cylindrical form from what is met with in the other genera, 

 as well as in being mostly single-rooted. The proportions of 

 the skull are almost the reverse of what is met with in the other 

 genera. The preorbital portion forms nearly half the length of 

 the skull, and has a proportionally remarkable breadth, the 

 width of the skull at the base of the zygoinatic process of 

 the maxillary considerably exceeding the greatest width of the 

 brain-case, instead of being only about half as wide, as is the 

 case in Phoca. The brain-case is disproportionately small, be- 

 ing scarcely longer than in Phoca grcenlandica or P. vituUna, 

 although the total length of the skull is one-third greater, while 

 the breadth of the brain-case is actually less ! The opening of 

 the anterior nares is simply immense, in comparison with any 

 other representative of the subfamily Phocina, being eveu larger 

 than in Cystophora. The interorbital region, correlatively with 

 the nasal passages, is also greatly thickened. In old age, at 

 least in the males, the sagittal crest is greatly developed (15 mm. 

 high in a specimen before me), as are also the occipital ridges. 

 The postorbital region thus strikingly recalls the highly devel- 

 oped crests of the Otaries. In respect to the general skeleton 

 I am unable to speak, my material being limited to two skulls 

 and a few skins. 



GENERAL HISTORY AND DISCUSSION OF THE "GENUS 

 PUSA" OF SCOPOLI. The genus Halichcenis, distinguished by 

 Nilssou in 1820, has been until recently without a synonym. 

 In 1877, however. Dr. Gill revived the name Pusa\ of Scopoli, 



*Snppl. Cat, Seals and Whales, 1871, p. 3. 



t Concerning the etymology, signification, and early nse of this singular 

 word the following may be of interest. According to Houttnyu (Natuur- 

 lyke Historie, etc., Deel i, Stuk ii, 1761, p. 15) and Muller (Natursystem, 

 Theil i, 1773, p. 199) Pusa is simply the Greenlaudic word for Seal. The 

 first use of the word by European authors seems to have been by Anderson 

 (174G), and soon after by Cranz, who, however, spelled it Pita, and gave it 

 as the Greenlandic equivalent of the Latin Pltoca (Historie von Grceul., 



