﻿THREE 
  NEW 
  LAND 
  SHELLS 
  FROM 
  MEXICO 
  

  

  By 
  Paul 
  Bartsch 
  

  

  Curator, 
  Division 
  of 
  Mollusks, 
  United 
  States 
  National 
  Museum 
  

  

  In 
  a 
  recent 
  sending 
  of 
  land 
  mollusks 
  from 
  Mexico, 
  received 
  from 
  

   C. 
  R. 
  Orcutt, 
  are 
  three 
  new 
  Urocoptid 
  land 
  shells, 
  which 
  are 
  here 
  

   described. 
  

  

  HOLOSPIRA 
  (HOLOSPIRA) 
  ORCUTTI, 
  new 
  species 
  

  

  Plate 
  1, 
  figs. 
  5, 
  6 
  

  

  Shell 
  large, 
  cylindro-conic, 
  flesh 
  colored 
  with 
  a 
  pinkish 
  flush. 
  

   The 
  last 
  half 
  of 
  the 
  last 
  turn 
  marked 
  with 
  pale-brown, 
  which 
  is 
  also 
  

   the 
  color 
  of 
  the 
  base. 
  Nuclear 
  whorls 
  2.3, 
  large, 
  strongly 
  rounded, 
  

   smooth, 
  forming 
  an 
  almost 
  mammillate 
  apex. 
  Early 
  postnuclear 
  

   whorls 
  increasing 
  rapidly 
  in 
  size, 
  marked 
  by 
  rather 
  strongly 
  decidedly 
  

   retractively 
  slanting 
  threadlike 
  riblets 
  which 
  are 
  separated 
  by 
  spaces 
  

   three 
  and 
  four 
  times 
  the 
  width 
  of 
  the 
  riblets. 
  These 
  riblets 
  become 
  

   evanescent 
  on 
  the 
  sixth 
  turn 
  and 
  on 
  the 
  whorls 
  that 
  follow 
  there 
  are 
  

   mere 
  indications 
  of 
  them. 
  The 
  last 
  turn 
  and 
  a 
  half 
  is 
  again 
  ribbed 
  

   and 
  on 
  the 
  latter 
  portion 
  of 
  the 
  last 
  whorl 
  the 
  riblets 
  are 
  almost 
  

   lamellar. 
  The 
  early 
  whorls 
  are 
  slightly 
  over-hanging, 
  while 
  the 
  rest 
  

   are 
  appressed 
  at 
  the 
  summit. 
  About 
  one-tenth 
  of 
  the 
  last 
  turn 
  is 
  

   free 
  at 
  the 
  summit, 
  and 
  the 
  angle 
  of 
  the 
  summit 
  stands 
  out 
  markedly 
  

   here. 
  There 
  is 
  a 
  subobsolete 
  constriction 
  where 
  the 
  side 
  of 
  the 
  

   whorl 
  meets 
  the 
  basal 
  portion, 
  the 
  axial 
  ribs 
  extending 
  over 
  the 
  base 
  

   into 
  the 
  umbilical 
  region. 
  The 
  umbilicus 
  is 
  rimate, 
  but 
  not 
  open. 
  

  

  Aperture 
  rather 
  large 
  with 
  a 
  very 
  broad, 
  thick, 
  slightly 
  reflected, 
  

   wide, 
  shining 
  peristome. 
  Interior 
  of 
  aperture 
  pale-brown. 
  

  

  The 
  type, 
  Cat. 
  No. 
  361960, 
  U.S.N.M., 
  has 
  14.5 
  whorls 
  and 
  measures: 
  

   Altitude, 
  25.3 
  mm.; 
  greater 
  diameter, 
  8.4 
  mm. 
  It 
  was 
  collected 
  on 
  

   a 
  limestone 
  paredon 
  at 
  Coahuila, 
  Mexico. 
  

  

  No. 
  2594— 
  Proceedings 
  U. 
  S. 
  National 
  Museum, 
  Vol. 
  67, 
  Art. 
  22. 
  

  

  64205— 
  25f 
  1 
  

  

  