﻿TJRUNCATELLA. 
  Panama 
  Shells. 
  437 
  

  

  31V. 
  Truncatella 
  Bairdiana. 
  Nov. 
  sp. 
  

  

  Shell 
  cylindric 
  : 
  of 
  a 
  rich 
  amber 
  color 
  : 
  with 
  rather 
  small 
  

   crowded 
  ribs, 
  which 
  are 
  obsolete 
  behind 
  the 
  labrum, 
  less 
  pro- 
  

   minent 
  on 
  the 
  convexity 
  of 
  the 
  whorls, 
  well 
  developed 
  ante- 
  

   riorly, 
  in 
  number 
  about 
  twenty 
  -four 
  on 
  the 
  penult 
  whorl: 
  apex 
  

   acute, 
  truncate 
  with 
  the 
  loss 
  of 
  four 
  whorls 
  : 
  spire 
  with 
  the 
  out- 
  

   lines 
  slightly 
  curvilinear 
  ; 
  whorls 
  nearly 
  four 
  after 
  truncation, 
  

   convex, 
  with 
  a 
  well 
  impressed 
  suture 
  : 
  aperture 
  ovate, 
  slightly 
  

   effuse 
  above: 
  labrum 
  advanced 
  along 
  the 
  middle, 
  reflected, 
  

   double 
  : 
  labium 
  with 
  a 
  thick 
  deposit, 
  continuous 
  with 
  the 
  

   labrum. 
  

  

  Mean 
  divergence 
  about 
  22°, 
  being 
  considerably 
  less 
  in 
  the 
  

   lower 
  whorls 
  and 
  more 
  above 
  ; 
  length 
  after 
  truncation, 
  .21 
  inch 
  ; 
  

   breadth 
  .075 
  inch 
  ; 
  length 
  of 
  spire 
  .15 
  inch. 
  

  

  This 
  species 
  must 
  resemble 
  T. 
  scalariformis 
  Eeeve 
  from 
  the 
  

   island 
  of 
  Annaa 
  ; 
  but 
  that 
  shell 
  is 
  figured 
  with 
  five 
  whorls 
  after 
  

   truncation, 
  in 
  color 
  it 
  is 
  described 
  as 
  " 
  luteola," 
  and 
  the 
  labrum 
  

   is 
  said 
  to 
  be 
  sharp 
  and 
  simple. 
  

  

  Station. 
  — 
  Under 
  a 
  heap 
  of 
  stones 
  at 
  the 
  high 
  water 
  mark 
  of 
  

   spring 
  tides. 
  

  

  Habitat. 
  — 
  Panama 
  ; 
  C. 
  B. 
  A. 
  ! 
  

  

  400 
  specimens 
  were 
  collected 
  at 
  the 
  bottom 
  of 
  the 
  sea 
  wall 
  of 
  

   Panama. 
  

  

  One 
  specimen 
  has 
  come 
  to 
  maturity 
  without 
  the 
  loss 
  of 
  the 
  

   apex, 
  which, 
  however, 
  is 
  white 
  and 
  cretaceous 
  from 
  partial 
  

   decay. 
  

  

  We 
  dedicate 
  this 
  species 
  to 
  Professor 
  S. 
  F. 
  Baird, 
  whose 
  

   name 
  is 
  so 
  well 
  known 
  to 
  Herpetologists. 
  

  

  318. 
  Truncatella 
  (?l) 
  dubiosa. 
  Nov. 
  sp. 
  

  

  Shell 
  ovate 
  conic 
  : 
  translucent, 
  deep 
  yellowish 
  brown 
  : 
  thin, 
  

   smooth, 
  and 
  shining 
  : 
  apex 
  subacute 
  : 
  spire 
  with 
  the 
  outlines 
  

   moderately 
  curvilinear: 
  whorls 
  ,six, 
  convex, 
  with 
  a 
  well 
  

  

  