﻿NASSA. 
  Panama 
  Shells. 
  283 
  

  

  JVASSA. 
  Mr. 
  Powis 
  has 
  described 
  in 
  the 
  Proceedings 
  

   of 
  the 
  Zoological 
  Society 
  of 
  London, 
  1835, 
  pp. 
  95, 
  96, 
  seven 
  

   species 
  of 
  this 
  genus 
  from 
  Panama 
  and 
  from 
  other 
  parts 
  of 
  

   the 
  same 
  Zoological 
  province. 
  We 
  obtained 
  fourteen 
  species, 
  

   two 
  (perhaps 
  three) 
  of 
  which 
  answer 
  to 
  the 
  descriptions 
  by 
  

   Mr, 
  Powis. 
  

  

  43. 
  ]\assa 
  canescens. 
  Nov. 
  sp. 
  

  

  Shell 
  rather 
  long, 
  ovate 
  conic 
  : 
  pale 
  brown 
  on 
  all 
  the 
  

   raised 
  portions 
  of 
  the 
  surface, 
  with 
  the 
  interspaces 
  pale 
  gray 
  : 
  

   with 
  ten 
  or 
  eleven 
  very 
  prominent 
  narrow 
  ribs, 
  and 
  many 
  

   raised 
  spiral 
  lines, 
  which 
  are 
  not 
  interrupted 
  by 
  the 
  ribs, 
  and 
  

   of 
  which 
  two 
  on 
  the 
  middle 
  of 
  the 
  whorls 
  and 
  some 
  anteriorly 
  

   are 
  larger 
  : 
  spire 
  with 
  the 
  outlines 
  nearly 
  rectilinear 
  : 
  apex 
  

   acute 
  : 
  whorls 
  eight 
  or 
  nine, 
  subangular 
  in 
  the 
  middle, 
  with 
  a 
  

   well 
  impressed 
  suture 
  ; 
  last 
  whorl 
  moderately 
  ventricose, 
  an- 
  

   teriorly 
  spirally 
  subcanalicuJate 
  : 
  aperture 
  subelliptical 
  : 
  labruin 
  

   subacute, 
  much 
  thickened 
  by 
  a 
  varix 
  a 
  little 
  behind 
  the 
  edge, 
  

   finely 
  grooved 
  within 
  : 
  labium 
  finely 
  wrinkled, 
  a 
  little 
  dilated 
  

   but 
  not 
  appressed 
  : 
  notch 
  large 
  and 
  deep. 
  

  

  Mean 
  divergence 
  about 
  50° 
  ; 
  length 
  1.05 
  inch 
  ; 
  breadth 
  .6 
  

   inch 
  ; 
  length 
  of 
  spire 
  .6 
  inch. 
  

  

  Station. 
  — 
  Unknown. 
  

  

  Habitat. 
  — 
  Panama 
  ; 
  C. 
  B. 
  A 
  ! 
  

   1 
  specimen 
  was 
  obtained. 
  

  

  44. 
  IVassa 
  collaria. 
  Nov. 
  sp. 
  

  

  Synonymy. 
  

  

  Nassa 
  collaria^ 
  Gould 
  MSS. 
  

  

  Shell 
  ovate 
  conic 
  : 
  dingy 
  white, 
  with 
  a 
  dark 
  reddish 
  

   brown 
  band 
  on 
  each 
  side 
  of 
  the 
  whorl: 
  with, 
  on 
  each 
  whorl, 
  

   about 
  ten 
  or 
  twelve 
  ribs, 
  which 
  are 
  smaller 
  and 
  more 
  approxi- 
  

  

  