﻿art. 
  4 
  SCULPTURE 
  OF 
  MUSSEL 
  SHELLS 
  MARSHALL 
  11 
  

  

  received 
  from 
  Wheatly. 
  It 
  is 
  figured 
  on 
  plate 
  4, 
  figure 
  1. 
  The 
  

   locality 
  given 
  for 
  this 
  specimen 
  is 
  Amazon. 
  Third, 
  no 
  specimen 
  has 
  

   ever 
  been 
  reported-from 
  Southeastern 
  Asia. 
  Fourth, 
  the 
  character 
  of 
  

   the 
  periostracum. 
  Were 
  all 
  other 
  evidence 
  lacking, 
  this 
  would 
  be 
  

   sufficient 
  to 
  establish 
  the 
  fact 
  of 
  a 
  South 
  American 
  origin 
  for 
  the 
  

   shell. 
  The 
  radiating 
  microscopic 
  threads 
  are 
  exactly 
  like 
  those 
  found 
  

   in 
  Diplodontitis 
  cookei 
  Marshall, 
  Anodontites 
  tenebricosus 
  Lea, 
  

   M 
  ono 
  condyloma 
  franciscana 
  Moricand, 
  and 
  many 
  other 
  species 
  of 
  

   South 
  American 
  naiad. 
  The 
  striae 
  number 
  about 
  90 
  to 
  the 
  milli- 
  

   meter. 
  

  

  In 
  what 
  genus 
  " 
  Solenaia 
  " 
  falcata 
  should 
  be 
  placed 
  remains 
  an 
  

   open 
  question. 
  The 
  data 
  at 
  hand 
  is 
  not 
  sufficient 
  to 
  answer 
  that 
  

   question, 
  and 
  we 
  must 
  wait 
  for 
  further 
  details 
  as 
  to 
  anatomy, 
  breed- 
  

   ing 
  habits, 
  and 
  beak 
  sculpture. 
  The 
  U. 
  S. 
  National 
  Museum 
  con- 
  

   tains 
  six 
  speciment 
  representing 
  four 
  species 
  of 
  undoubted 
  Solenaia. 
  

   The 
  periostracum 
  of 
  these 
  is 
  altogether 
  different 
  from 
  that 
  of 
  falcata 
  

   and 
  shows 
  no 
  sign 
  of 
  radiating 
  threads. 
  To 
  place 
  it 
  in 
  the 
  genus 
  

   Solenaia 
  would 
  involve 
  a 
  faunistic 
  mixing 
  that 
  would 
  be 
  unusual, 
  

   namely. 
  South 
  America 
  and 
  Eastern 
  Asia, 
  and 
  the 
  difference 
  between 
  

   the 
  periostracum 
  of 
  falcata 
  and 
  that 
  of 
  species 
  whose 
  right 
  to 
  a 
  

   place 
  in 
  the 
  genus 
  Solenaia 
  is 
  undoubted 
  would 
  involve 
  a 
  mixing 
  of 
  

   not 
  only 
  generic 
  characters 
  but 
  of 
  features 
  which 
  are 
  believed 
  to 
  be 
  

   family 
  characteristics. 
  

  

  Granting 
  that 
  " 
  Solenaia 
  " 
  falcata 
  is 
  a 
  South 
  American 
  shell 
  and 
  

   that 
  it 
  does 
  not 
  belong 
  in 
  the 
  genus 
  Solenaia, 
  the 
  next 
  step 
  is 
  to 
  de- 
  

   fine 
  its 
  position 
  among 
  the 
  South 
  American 
  Naiades. 
  It 
  was 
  described 
  

   as 
  a 
  Mycetopus 
  (—Mycetopoda) 
  . 
  In 
  a 
  cursory 
  consideration 
  of 
  it 
  

   one 
  would 
  naturally 
  place 
  it 
  in 
  or 
  very 
  near 
  the 
  genus 
  Mycetopoda, 
  

   this 
  allocation 
  being 
  made 
  chiefly 
  because 
  of 
  its 
  elongated 
  form. 
  

   Possibty 
  it 
  does 
  belong 
  to 
  that 
  genus, 
  but 
  it 
  is 
  to 
  be 
  doubted. 
  It 
  may 
  

   belong 
  in 
  the 
  genus 
  Anodontites, 
  as 
  it 
  shows 
  some 
  relationship 
  to 
  

   arcuate 
  specimens 
  of 
  the 
  tenebricosus 
  group. 
  Its 
  position 
  here 
  like- 
  

   wise 
  is 
  doubtful. 
  In 
  radiating 
  threads 
  its 
  periostracum 
  differs 
  

   widely 
  from 
  that 
  of 
  Mycetopoda, 
  in 
  which 
  genus 
  what 
  radiating 
  

   threads 
  have 
  been 
  observed 
  being 
  far 
  from 
  the 
  kind 
  usual 
  in 
  

   Mutelidae. 
  Of 
  falcata 
  it 
  may 
  be 
  said 
  that 
  its 
  sinulus 
  is 
  not 
  dis- 
  

   tinctly 
  of 
  the 
  Mutelid 
  type, 
  not 
  being 
  clearly 
  triangular 
  nor 
  sub- 
  

   equilateral. 
  This 
  may 
  be 
  due 
  to 
  the 
  great 
  length 
  of 
  the 
  shell 
  in 
  

   proportion 
  to 
  its 
  height. 
  The 
  species 
  ma}^ 
  require 
  a 
  new 
  genus 
  to 
  

   accommodate 
  it. 
  

  

  Since 
  the 
  above 
  was 
  written 
  our 
  library 
  has 
  received 
  a 
  copy 
  of 
  a 
  

   paper 
  entitled 
  " 
  Nayades 
  del 
  Viaje 
  al 
  Pacifico," 
  by 
  F. 
  Hass, 
  pub- 
  

   lished 
  in 
  Trabajos 
  del 
  Museo 
  Nacional 
  de 
  Ciencias 
  Naturales, 
  Zoo- 
  

   logical 
  series, 
  Number 
  25 
  (Madrid, 
  Spain, 
  Aug. 
  1916). 
  In 
  this 
  paper 
  

   the 
  supposed 
  new 
  species 
  Mycetopoda 
  bolivari 
  Hass 
  is 
  described 
  on 
  

   page 
  36 
  and 
  figured 
  on 
  plate 
  2, 
  figure 
  2. 
  It 
  comes 
  from 
  Rio 
  

  

  