ALLEN: mammalia: phocid^. * 85 



Externally Oxymycterus jnicrotis is a miniature of Akodon macronyx 

 with a relatively much shorter tail. It exactly resembles in coloration 

 above and in the texture of the pelage Oxymycterus kmosiis, but the latter 

 has whiter under parts, is very much smaller, has a much longer tail, and 

 small, non-fossorial claws ; but the skulls of the two are very similar in 

 general contour, differing only in size and slightly in details. O. microtis 

 thus combines the large fossorial claws of the Akodon [Chelemys] ma- 

 cronyx group with the cranial characters and weak dentition of the O. 

 lanosns type. The narrow line separating Akodon and Oxymycterus is 

 thus still further narrowed by the present annectent link. 



Since the foregoing description was published Mr. Oldfield Thomas 

 (/. c.) has expressed the opinion that, "From the descriptions given it 

 seems not impossible that both ^ Hesperomys [Acodon) Michaelseni: 

 Matchie, and ' Oxymycterus microtis; Allen, belong to Notiomys, as their 

 long claws, short tails, and very small molars agree precisely with what 

 is found in that group." With the skull and skins of O. micro^us before 

 me, however, I see no reason for not viewing the species as far better 

 referable to Oxymycterus than to Notiomys, judging Notiomys by the 

 published figures of the species, including the skull. 



Order FER^. 



Suborder Pinnipedia. 



Family PHOCID^. 



The Phocids or Earless Seals are represented in the southern hemi- 

 sphere by five species, referable to as many genera, of which three have 

 been recorded from the Straits of Magellan, the coast of Patagonia, or 

 the Falkland Islands, and hence come within the limits of the present 

 treatise. These are the Leopard Seal [Hydrurga kptonyx), Weddell's 

 Seal {Leptonychotes weddellii), and the Sea Elephant [Miroimga leoninus). 

 There is also a record of the capture of several examples of the Crab- 

 eating Seal {Lobodon carcinophaga) near San Isidro, a few miles north of 

 the city of Buenos Aires ;i but otherwise than this both this species and 

 Ross's Seal [Ommatophoca rossii) are known only from the vicinity of 

 the pack-ice of the antarctic seas. Although the occurrence of Lobodon 



' Berg, Com. Mus. Buenos Aires, I, 1898, p. 15. 



