﻿PRESTON: 
  ON 
  ABYSSINIA.N 
  MOLLUSOA. 
  165 
  

  

  whitish 
  ; 
  base 
  of 
  shell 
  convex 
  ; 
  columella 
  white, 
  excavated, 
  a 
  thin, 
  

   roughish 
  callus 
  joining 
  it 
  with 
  the 
  lip 
  above 
  ; 
  labrum 
  acute, 
  arcuate 
  ; 
  

  

  aperture 
  wide, 
  ovate. 
  Alt. 
  15-5, 
  diam. 
  maj. 
  24, 
  min. 
  16-75 
  mm. 
  ; 
  

   aperture, 
  alt. 
  14, 
  diam. 
  14-5 
  mm. 
  

  

  Helicella 
  (Lejeania) 
  Rosenbeegi, 
  n.sp. 
  

  

  Shell 
  globosely 
  turbinate, 
  perforate, 
  slightly 
  shining, 
  pale 
  brown, 
  

   painted 
  with 
  transverse 
  streaks 
  and 
  spiral 
  bands 
  of 
  white 
  ; 
  whorls 
  6, 
  

   flattened, 
  the 
  last 
  descending 
  in 
  front, 
  sculptured 
  with 
  coarse, 
  trans- 
  

   verse, 
  arcuate 
  riblets, 
  and 
  undulating, 
  spiral, 
  scratch-like 
  strise 
  ; 
  

   sutures 
  somewhat 
  lightly 
  impressed, 
  minutely 
  crenellate 
  ; 
  base 
  of 
  

   shell 
  moderately 
  inflated 
  ; 
  umbilicus 
  somewhat 
  open, 
  deep 
  ; 
  columella 
  

  

  reflexed, 
  whitish, 
  descending 
  obliquely, 
  excavated 
  in 
  the 
  middle 
  ; 
  

   labrum 
  thin, 
  acute, 
  slightly 
  reflexed 
  ; 
  aperture 
  oblique, 
  broadly 
  sub- 
  

   lunate. 
  Alt, 
  11-25, 
  diam. 
  maj. 
  16, 
  min. 
  13-5 
  mm. 
  ; 
  aperture, 
  alt. 
  6-75, 
  

   diam. 
  6 
  mm. 
  

  

  A 
  very 
  variable 
  species 
  of 
  which 
  the 
  principal 
  forms 
  are 
  described 
  

   below. 
  

  

  Var. 
  DEPRESSA. 
  

  

  Much 
  more 
  depressed 
  than 
  the 
  typical 
  form. 
  Alt. 
  7, 
  diam. 
  maj. 
  

   13-5, 
  min. 
  13 
  mm. 
  ; 
  aperture, 
  alt. 
  5, 
  diam. 
  6 
  mm. 
  

  

  Var. 
  ALBIDA. 
  

  

  More 
  depressed 
  than 
  the 
  type 
  and 
  nearly 
  white, 
  the 
  brown 
  ground 
  

   colouring 
  being 
  changed 
  to 
  very 
  pale 
  greyish-white, 
  whilst 
  the 
  white 
  

   bands 
  and 
  streaks 
  remain 
  in 
  an 
  intensified 
  form. 
  Alt. 
  8, 
  diam. 
  maj. 
  

   14-25, 
  min. 
  10-5 
  mm. 
  ; 
  aperture, 
  alt. 
  575, 
  diam. 
  6 
  mm. 
  

  

  Btjliminus 
  affinis, 
  n.sp. 
  

  

  Shell 
  small, 
  thin, 
  hyaline, 
  the 
  earlier 
  whorls 
  bronze- 
  coloured, 
  the 
  

   later 
  yellowish-brown 
  horn 
  colour 
  ; 
  whorls 
  6|, 
  convex, 
  sculptured 
  

   with 
  very 
  fine, 
  regular, 
  oblique, 
  transverse 
  growth-strise 
  ; 
  sutures 
  

  

  VOL. 
  IX. 
  — 
  SEPTEMBER, 
  1910. 
  12 
  

  

  