﻿414 
  

  

  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  

  

  Rejerred 
  material. 
  — 
  Eleven 
  mandibles 
  from 
  the 
  same 
  locality 
  and 
  

   C. 
  M. 
  9136 
  from 
  the 
  upper 
  levels 
  of 
  locahty 
  No. 
  24BW18, 
  locally 
  

   known 
  as 
  the 
  Old 
  Hadcock 
  Ranch. 
  

  

  Description. 
  — 
  ^Mi 
  elongate, 
  anteroconid 
  small, 
  anterior 
  cingulum 
  

   well 
  developed, 
  anterior 
  arm 
  of 
  protoconid 
  connected 
  to 
  anteroconid 
  

   and 
  posterior 
  arm 
  to 
  metaconid, 
  mesolophid 
  well 
  developed 
  and 
  ex- 
  

   tending 
  nearly 
  halfway 
  to 
  inner 
  margin 
  of 
  tooth, 
  inner 
  end 
  of 
  posterior 
  

   cingulum 
  close 
  to 
  but 
  not 
  united 
  with 
  entoconid; 
  M2 
  quadrangular, 
  

   nearly 
  as 
  broad 
  as 
  long, 
  lingual 
  portion 
  of 
  anterior 
  cingulum 
  obsolete, 
  

   posterior 
  arm 
  of 
  protoconid 
  closely 
  applied 
  to 
  entoconid 
  and 
  extend- 
  

   ing 
  nearly 
  to 
  inner 
  margin 
  of 
  tooth, 
  no 
  mesolophid, 
  posterior 
  cingulum 
  

   as 
  in 
  Mil 
  M3 
  subtriangular 
  in 
  outline, 
  sharply 
  constricted 
  posterior 
  

   to 
  protoconid, 
  anterior 
  cingulum 
  as 
  in 
  M2, 
  posterior 
  arm 
  of 
  protoconid 
  

   united 
  to 
  metaconid 
  at 
  base, 
  no 
  mesolophid 
  or 
  mesoconid. 
  

  

  US/\/M 
  

   /6B33 
  

  

  Figure 
  47. 
  — 
  Occlusal 
  view 
  of 
  the 
  type 
  (USNM 
  18833) 
  of 
  Eumys 
  spokanensis, 
  new 
  species, 
  

   anterior 
  end 
  to 
  the 
  right. 
  X 
  7. 
  

  

  Variation. 
  — 
  This 
  species 
  shows 
  less 
  variation 
  than 
  the 
  other 
  two. 
  

   The 
  teeth 
  have 
  the 
  appearance 
  of 
  being 
  shorter, 
  for 
  their 
  breadth, 
  

   and 
  the 
  cusps 
  more 
  crowded, 
  but 
  the 
  measurements 
  do 
  not 
  bear 
  this 
  

   out. 
  On 
  M2 
  and 
  M3 
  the 
  posterior 
  arm 
  of 
  the 
  protoconid 
  often 
  be- 
  

   comes 
  united 
  with 
  the 
  metaconid 
  with 
  wear. 
  The 
  lingual 
  portion 
  

   of 
  the 
  anterior 
  cingulum 
  of 
  M2 
  and 
  M3 
  is 
  represented 
  by 
  a 
  vertical 
  

   fold 
  near 
  the 
  midline 
  of 
  the 
  tooth 
  and 
  soon 
  becomes 
  obliterated 
  with 
  

   wear. 
  Measurements 
  of 
  teeth 
  (in 
  millimeters) 
  : 
  

  

  Ml 
  A/2 
  Mj 
  

  

  Mi-i 
  

  

  USNM 
  No. 
  Length 
  Width 
  Length 
  Width 
  Length 
  Width 
  

  

  18833 
  (Type) 
  7.8 
  2.7 
  1.9 
  2.4 
  2.2 
  2.5 
  2.0 
  

  

  18831. 
  _A 
  7.4 
  2.5 
  1.8 
  2.5 
  2.1 
  2.3 
  2.0 
  

  

  18843 
  7. 
  8 
  »2. 
  6 
  2.0 
  2.5 
  2.2 
  2.4 
  2.0 
  

  

  18840 
  7.6 
  2.6 
  1.9 
  2.4 
  2.1 
  2.5 
  2.0 
  

  

  18841 
  8.1 
  2.9 
  2.0 
  2.5 
  2.3 
  2.4 
  2.1 
  

  

  18847 
  7.7 
  2.7 
  2.0 
  2.3 
  2.2 
  2.3 
  2.1 
  

  

  18830 
  7.5 
  2.6 
  1.9 
  2.4 
  2.2 
  2.4 
  2.0 
  

  

  18846 
  7.8 
  2.6 
  1.9 
  2.3 
  2.2 
  2.6 
  2.3 
  

  

  18842 
  8.0 
  2.7 
  1.9 
  2.5 
  2.2 
  2.4 
  2.2 
  

  

  18845 
  7.6 
  2.7 
  1.8 
  2.2 
  2.0 
  2.5 
  2.0 
  

  

  > 
  Estimated. 
  

  

  