﻿290 
  Panama 
  Shells. 
  puRPURiDiE. 
  

  

  ture 
  ; 
  last 
  whorl 
  spirally 
  canaliculate 
  on 
  the 
  left 
  side 
  : 
  aper- 
  

   ture 
  subelliptical 
  : 
  labrura 
  rather 
  sharp, 
  thickened 
  by 
  a 
  broad 
  

   varix, 
  coarsely 
  grooved 
  within 
  : 
  labium 
  well 
  thickened, 
  not 
  

   appressed, 
  with 
  two 
  small 
  wrinkles 
  anteriorly 
  : 
  notch 
  deep. 
  

  

  It 
  resembles 
  N. 
  versicolor 
  (v. 
  infra) 
  var. 
  striatula: 
  but 
  

   besides 
  being 
  more 
  coarsely 
  striated 
  and 
  minutely 
  ribbed, 
  the 
  

   whorls 
  are 
  much 
  more 
  convex. 
  

  

  Mean 
  divergence 
  about 
  48°; 
  length 
  .58 
  inch; 
  breadth 
  .31 
  

   inch 
  ; 
  length 
  of 
  spire 
  .33 
  inch. 
  

  

  Station. 
  — 
  Unknown. 
  

  

  Habitat.— 
  Tahoga. 
  ; 
  C. 
  B. 
  A. 
  I 
  

   2 
  specimens 
  were 
  obtained, 
  

  

  55. 
  ]\assa 
  Tersicolor. 
  — 
  Nov. 
  sp. 
  

  

  Shell 
  long 
  ovate 
  conic 
  : 
  pale 
  yellowish 
  brown, 
  or 
  nearly 
  

   white, 
  with 
  a 
  darker 
  sutural 
  line, 
  or 
  blackish 
  brown 
  : 
  some- 
  

   times 
  the 
  ends 
  or 
  the 
  summits 
  of 
  the 
  ribs 
  are 
  whiter 
  than 
  the 
  

   interspaces 
  ; 
  sometimes 
  the 
  sutural 
  fascia 
  covers 
  the 
  anterior 
  

   part 
  of 
  the 
  last 
  whorl 
  : 
  with, 
  on 
  each 
  whorl, 
  nine 
  or 
  ten 
  narrow 
  

   very 
  prominent 
  ribs; 
  with 
  very 
  minute 
  spiral 
  strise, 
  which 
  

   are 
  nearly 
  obsolete 
  on 
  the 
  middle 
  of 
  the 
  whorls 
  ; 
  spire 
  with 
  

   the 
  outlines 
  nearly 
  or 
  quite 
  rectilinear 
  : 
  apex 
  acute 
  : 
  whorls 
  

   eight, 
  slightly 
  convex, 
  with 
  a 
  well 
  impressed 
  suture 
  ; 
  last 
  

   whorl 
  spirally 
  canaliculate 
  anteriorly: 
  aperture 
  subelliptical: 
  

   labrum 
  subacute, 
  thickened 
  with 
  a 
  stout 
  varix 
  : 
  labium 
  thick- 
  

   ened, 
  not 
  appressed, 
  finely 
  wrinkled 
  : 
  notch 
  deep. 
  Var. 
  stria- 
  

   tula 
  is 
  covered 
  with 
  very 
  distinct 
  striae. 
  

  

  Mean 
  divergence 
  about 
  45° 
  ; 
  length 
  .6 
  inch 
  ; 
  breadth 
  .33 
  

   inch 
  ; 
  length 
  of 
  spire 
  .35 
  inch. 
  

  

  N. 
  ambigua, 
  the 
  Caribbean 
  analogue, 
  is 
  also 
  an 
  extremely 
  

   variable 
  species. 
  

  

  Station. 
  — 
  Unknown. 
  

  

  