56 
is  seen  through  it.  Whorls  semilunar  in  section, 
a  little  nai  rower  above,  each  whorl  extensi¬ 
vely  covered  by  the  next,  which  makes  the 
counting  difficult.  The  number  in  the  lar¬ 
gest  specimens  is  5  or  5  1/2  the  breadth 
little  more  than  4,  the  height  little  more 
than  1  1/2  mm. 
The  whorls  show  a  sculpture  consisting 
of  longitudinal  lines  of  very  small,  round  or 
more  or  less  elongated  beads,  in  varying 
number.  On  the  upper  side  of  the  shell  they 
are  more  numerous  and  distinct.  Of  other  spe¬ 
cies  only  mclleus  shows  signs  of  a  corres¬ 
ponding,  though  somewhat  different  and  less 
distinct,  sculpture.  The  mouth  of  the  shell 
may  be  somewhat  expanded  and  show  a 
subterminal  black  ring. 
The  animal  comes  near  to  that  of  PI. 
melleus  but  is  darker.  It  also  has  a 
yellow  frontal  stripe  but  the  head  seems 
shorter  with  more  rounded  mouth  lobules. 
The  foot  too  is  shorter  and  less  pointed.  The 
eyes  also  are  large  but  less  distinctly  whi¬ 
te  rimmed.  The  dark  axial  thread  of  the  an¬ 
tennae  is  more  distinct  and  the  back  of  the 
foot  covered  with  black  points,  while,  the 
pallium  shows  inside  the  shell,  a  uniform 
black  colour,  varying  from  2  to  4  mm. 
Some  twenty  specimens  were  found  in 
the  middle  of  June  near  Manguinhos  in  a 
pool,  covered  with  Lemna  and  Azolla.  The 
species  which  has  habits  similar  to  those  of 
melleus  mihi  does  not  agree  with  any  of  the 
described  species.  Though  this  paper  was 
practically  printed,  I  was  still  able  to  include 
the  description  here. 
12.  Pianorbis  (SpirulinaJ  depressissimus 
MORICAND 
(Plate  XVIII  fig.  15  a,  b). 
This  species  may  be  recognised  by  the 
drawing;  it  was  described  by  the  author  of 
the  name  from  specmens  sent  from  Bahia. 
BAKER  quotes  an  observation  from  the  coast 
of  Ceará,  but  a  specimen  sent  me  as  depres¬ 
sissimus  by  FRANCISCO  DA  ROCHA  be¬ 
longs  to  cimex.  Personally  I  have  not  seen 
this  species,  which  seems  rather  rare. 
13.  Segmentina  paparyensis  n.  sp. 
(Plate  XVIII,  fig  20  a,  b). 
Original  description  by  F.  BAKER. 
“Shell  dextral,  broadly,  rather  deeply 
umbilicale,  rather  solid,  planorboid,  every¬ 
where  sculptured  with  minute,  retractive, 
sharp  costulae,  irregularly  sized  and  spaced, 
the  interspaces  being  broader,  and  showing 
under  a  strong  glass,  minute  spiral  striations 
on  the  base;  they  are  formed  by  the  crinkling  of 
the  radiating  costulae;  light  horn  coloured. 
Whorls  4,  regularly  increasing,  the  last  suban- 
gulate  below  the  periphery,  behind  the  outer 
lip  for  about  xh  turn,  scarcely  angulate 
below,  descending  very  sharply  at  the  mouth: 
apex  depressed,  only  the  last  two  whorls  reach¬ 
ing  the  upper  level  of  the  shell.  Aperture  very 
oblique,  subhorizontal,  rounded;  lip  simple, 
not  thickened  nor  sharpened,  slightly  reflec¬ 
ted  at  the  lower  angle,  extremities  approa¬ 
ching,  and  joined  by  a  slight  callus  in  some 
specimens  ;  aperture  lamellae  five,  two  parie¬ 
tal  and  three  (palatal)  on  the  outer  wall  ; 
upper  parietal  lamella  about  central,  the  lower 
about  midway  between  this  and  the  colu- 
mellar  junction  and  appearing  about  half  the 
size  to  external  inspection,  both  showing  a 
nearly  triangular  section,  the  lower  sides 
being  nearly  horizontal,  the  upper  ascending; 
lower  palatal  lamella  beginning  near  the  su¬ 
ture  and  extending  nearly  transversally  across 
the  base,  and  slightly  up  the  outer  side, 
straight  and  rather  evenly  arched  ;  remaining 
palatal  lamellae  deep  within  the  shell,  nearly 
horizontal,  short,  the  lower  one  slightly  larger. 
Greatest  diam.  6,  least  diam.  5,25,  alt. 
2  mm. 
Two  specimens  were  taken  near  the 
mouth  of  the  main  affluent  of  Papary  Lake. 
It  differs  fron  S.  janeirensis  Clessin  by  the 
unusually  deep  descent  of  the  last  whorl  at 
the  aperture”. 
Neither  in  Rio,  nor  in  the  north  of  Brazil 
did  I  observe  any  species  of  Segmentina. 
14.  Pianorbis  (Gyraultu)  anatinus  D’ORB. 
(Plate  XVIII,  Fig.  13  a,  b). 
According  to  BAKER,  this  species  des¬ 
cribed  from  the  river  Paraná,  occurs  in  an 
