﻿552 
  

  

  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  

  

  Structure. 
  — 
  A 
  series 
  of 
  transverse 
  sections 
  showed 
  that 
  the 
  number 
  

   of 
  tentacles 
  was 
  16, 
  and 
  that 
  they 
  were 
  arranged 
  in 
  the 
  typical 
  manner 
  

   with 
  reference 
  to 
  the 
  perfect 
  mesenteries, 
  namely, 
  one 
  over 
  each 
  

   directive 
  chamber, 
  three 
  over 
  each 
  sulculolateral 
  chamber, 
  and 
  two 
  

   over 
  each 
  of 
  the 
  other 
  chambers. 
  It 
  also 
  possesses 
  the 
  typical 
  arrange- 
  

   ment 
  of 
  the 
  mesenteries, 
  there 
  being 
  in 
  addition 
  to 
  the 
  eight 
  protoc- 
  

   nemes 
  a 
  pair 
  of 
  rudimentary 
  mesenteries 
  in 
  each 
  protocnemic 
  sulculo- 
  

   lateral 
  chamber 
  and 
  a 
  single 
  one 
  in 
  each 
  lateral 
  and 
  sulco-lateral 
  

   chamber. 
  As 
  is 
  usual 
  in 
  the 
  Edwardsiidse 
  these 
  rudimentary 
  mesen- 
  

   teries 
  are 
  confined 
  to 
  the 
  uppermost 
  part 
  of 
  the 
  column. 
  

  

  Fig. 
  1.— 
  Tbansveese 
  section 
  of 
  a 
  protocnemic 
  mesentery 
  of 
  Edwardsiella 
  californica. 
  mp, 
  

   MUSCLE 
  pennon; 
  nc, 
  mematocyst 
  capsule; 
  pm, 
  parietal 
  muscle. 
  

  

  The 
  muscle 
  pennons 
  of 
  the 
  protocnemes 
  have 
  a 
  very 
  characteristic 
  

   pattern. 
  They 
  resemble 
  those 
  of 
  E. 
  pudica 
  {=E. 
  adenensis 
  Faurot) 
  

   in 
  that 
  the 
  mesenteries 
  join 
  them 
  almost 
  at 
  the 
  middle 
  of 
  their 
  

   breadth 
  (fig. 
  1), 
  a 
  condition 
  that 
  evidently 
  results 
  from 
  the 
  excessive 
  

   development 
  of 
  the 
  lateral 
  or 
  basal 
  lamella 
  of 
  the 
  pennon, 
  which 
  

   seems 
  to 
  be 
  a 
  direct 
  continuation 
  of 
  the 
  axial 
  mesogloea 
  of 
  the 
  pennon 
  

   and, 
  like 
  it, 
  bears 
  numerous 
  lamellae, 
  which, 
  however, 
  are 
  secondary 
  

   branches. 
  In 
  E. 
  pudica 
  these 
  are 
  arranged 
  bipinnately 
  on 
  the 
  basal 
  

   lamella, 
  but 
  in 
  the 
  present 
  species, 
  wliile 
  the 
  more 
  proximal 
  ones 
  are 
  

   arranged 
  in 
  a 
  palisade-like 
  manner 
  on 
  one 
  side 
  of 
  the 
  basal 
  lamella, 
  

   more 
  distally 
  the 
  latter 
  breaks 
  up 
  into 
  a 
  number 
  of 
  irregularly 
  branch- 
  

   ing 
  plates, 
  so 
  that 
  the 
  lateral 
  portion 
  of 
  the 
  pennon 
  has 
  the 
  appear- 
  

  

  