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Umvor 


MAN  UAL 


J 


ONCHOLOGY; 


STRUCTURAL  AND  SYSTEMATIC. 


WITTl  ILLUSTRATIONS  OF  Till-    si>K< 


BY  GEORGE  W.  TRYON,  JR. 

CONTINUATION   BY 

HENRY  A.  PILSBRY, 

CoNSKKVATOK    OK    VHK     CoXniouxiirAI.    SECTION     Ol      THE 
Ni.TlTRAL     SCIKNCKS     «)K     PlI  I  LADK1.1MI  1  A. 


Vol.   XIV. 

POLYPLACOPHORA, 

( Chitons. ) 
LEl'IDOl'LKURID.K,  ISCHNOCH1TONID.K,  CHITO>  PAU1D 


PHILADELPHIA  : 
isluMl  by  Concholop-i<-<<l  S<- 

ACADEMY  OF  NATURAL  SCI i 

OF   1MIII.AD1  1  1MI1A  5 


i-QMible  check  to  the  progress  of  Science  is  that  the  works  on  it  arc 
becoming  too  voluminous;  it  is  becoming  scholastic :  life  will  be  too  short  to  learn  it, 
and  no  time  will  be  left  for  discoveries.' 

e  told,  whoever  may  be  hurt  by  it.     There  is  no  doubt  that  some 
r*  endeavor  to  conceal  in  a  fog  of  mere  words  the  want  of  clear  and  well-defined 
idea*,  as  well  M  of  that  critical  knowledge  which  is  indispensable  in  Natural  Hi.-- 

this  that  has  arisen  that  legion  of  phantoms  which  so  effectually 
orieoced."— Anon.      Gardener's  C/imnitl,-.  /)<•<-.,  1854. 


FREFA.CE. 

The  present  volume  contains  a  monograph  of  the  importair 
extensive   Order   Polyplacophora,    commonly    known    an   Chiton*. 
Although  represented  by  many  species  in  all  seas,  tin  Chitons  have 
l>een   much  neglected  by  Conchologists.     This  may  !><•  due  to  the 
fact  that  their  characters  are  not  generally  understood,  or  even  seen 
in  ordinary  cabinet  specimens;  and  again,  no  illustrated  \\<>rk  treat- 
ing the  group  scientifically  has  hitherto  been  produced.     Certain  it 
is,  that  if  the  serious  study  of  this  group  be  once  begun,  its  at: 
tious  will  be  found  to  equal  or  excel  those  of  any  other  fain; 
The  numberless  modifications  of  form,  the  beautiful  adapt 
structure  to  life-habits  and  station,  the  marvelous  parallel  develop- 
ments, producing   almost   identical   structures   in   totally    diverse 
phyla, — all  distinguish  the  Polyplacophora  as  preeminently  int< 
ing  among  mollusks. 

The  author  begs  those  who  may  use  this  work  to  begin  by  taking 
apart  one  specimen  of  each  species  to  be  studied  ;  then  find  the  genus 
by  the  Key  on  page  xxviii.  After  a  certain  amount  of  practice  the 
genus  may  be  ascertained  by  removing  valves  vii  and  viii  only  ;  but 
guessing  it  from  the  external  features  is  in  most  cases  uncertain 
and  unscientific.  As  a  rule,  Chitons  tell  no  secrets  to  those  who 
will  not  take  the  trouble  to  disarticulate  them. 

It  is  hoped  that  describers  of  new  species  will  hereafter  state  the 
generic  characters  of  their  novelties.  It  is  as  rational  to  describe  a 
bivalve  without  examining  its  hinge-teeth,  as  to  notice  the  outside 
only  of  a  Chiton. 

The  synonymy  is  believed  to  be  practically  exhaustive,  ex 
that  useless  references  to  mere  lists  giving  no  new  information  are 
omitted. 

Attention  should  here  be  directed  to  the  new  theories  of  the  origin 
of  important  structures  of  shell  and  girdle,  given  on  pp.  i\,  \ii ;  to 
the  original  system  of  classification  (p.  xxiii),  and  the  phylogenies 
(pp.  xxvii,  xxviii). 

The  new  species  described  herein  which  are  credited  to  Car/ 
rest  upon  his  types  when  the  descriptions  are  g  »»  H*  Mt.  (as 

in  the  case  of  Callochiton  princeps,  p.  50).     In  cases  where  I  have 


given  original  descriptions  of  new  species,  whether  the  specific  names 
be  Carpenter's  or  my  own.  the  types  are  understood  to  be  the 
ment  described  by  me,  in  the  collection  of  the  Academy;  wherever 
and  whatever  the  original  <  mens  may  be.     A  case 

in  j...int  is  />  •//  ocrtor,  p.  60,  and  /.  conspicuus,  p.  63.     It  is 

liy  this  expedient  that  confusion  can  be  avoided  in  cases  of  real 
or  fancied  wrong  identification,  on  my  part,  of  Carpenter's  .V  . 
species. 

Many  new  species  not  illustrated  in  the  body  of  the  work  are 
figured  from  the  typos  in  the  Appendix.      The  Appendix  should 
always  be  consulted  when  a  species  is  not  found  elsewhere,  as  forms 
.M known  generic  position  have  been  included  therein. 

e  grateful  task  remains  of  acknowledging  assistance  from 
scientific  friends  and  institutions.  Through  the  intervention  of  DR. 
\\"M.  H.  DM. i..  Honorary  Curator  of  the  Department  of  Mollusks, 
U.  S.  National  Museum,  the  writer  has  received  from  S.  P.  LAV-- 
.  Secretary  of  the  Smithsonian  Institution,  the  drawings  and 
.i/v  prepared  by  the  lamented  PHILIP  P.  CARPENTER  upon  this 
group,  a  work  of  priceless  value,  embodying  the  results  of  many 
years  study  of  the  subject.  Throughout  the  text  of  this  volume  will  be 
foun  fcfl  from  this  MS.;  such  quotations  in  every  case  being 

idly  credited.  For  the  loan  of  a  large  number  of  type  spec- 
iim -us  from  the  Smithsonian  collections,  the  writer  is  indebted  to  the 

nued  kimlnesi  of  DR.  DALL.     To  J.  F.  WHITEAVES  of  the 

ula  Geological  Survey,  PROF.  WHITFIELD  of  the  American 

••urn  of  Natural   Hi>tory,  New  York  City,  PROFESSOR  F.  W. 

of  Christchurch,  New   Zealand,  and   many   other   con- 

chologists,  the  thanks  of  the  author  are  due  for  specimens  presented 

or  loaned. 

H.  A.  P. 


MANUAL    OF   CONCHOLOGY. 


MONOGRAPH  OF  THE  POLYPLACOPHORA. 


Class  AMPHINEURA. 


Bilaterally  symmetrical  mollusks,  the  nervous  system  consist 
of  four  (two  lateral  and  two  ventral  or  pedal)  parallel  cords,  me* 
in   a   cerebral   ganglion  ;  other  ganglia  feebly  or  not  developed. 
Anus  posterior  and  median  ;  head  without  tentacles  or  eyes. 

The  Amphineura  or  Isopleura  constitute  one  of  the  five  primary 
divisions  or  Classes  into  which  the  Mollusk  phylum  divides ;  and  it 
is,  in  many  respects,  the  most  primitive  of  all.  This  class  has  been 
by  most  authors  considered  a  sub-class  or  order  of  Gastropoda ;  but 
the  fact  should  be  distinctly  recognized  that  the  characters  com: 
to  Gastropoda  and  ^Amphineura  are  either  features  possess* 
(hypothetical)  primitive  rnollusk,  or  are  peculiarities  evolved  in 
response  to  similar  habits  of  life.  The  Patellidce  among  Gastropoda 
have  been  repeatedly  compared  to  the  Amphineurous  family 
Chitonidce;  but  the  branchial  cordon  of  Patell"  is. .in  no  way  homo- 
logous with  the  gills  (or  ctenidia)  of  Chiton,  and  the  nervous  and 
digestive  systems  are  profoundly  different. 

The  class  Amphineura  is  divisible  into  two  Orders  : 

Order  I.  POLYPLACOPHORA.     Dorsal  surface  bearing  eight  in 
eating  shelly  plates ;  head  divided  from  the  body ;  gills  numerous, 
occupying  a  lateral  groove  on  each  side  between  the  foot  and  the 
encircling  mantle ;  foot  adapted  to  creeping  ;  genital  organs  and 
nephridia  paired  ;  sexes  distinct ;  radula  well  developed. 

Order  II.  APLACOPHORA.  Body  subcylindrical  or  y.rmitorm, 
without  shelly  plates  or  valves;  foot  rudimentary  or  aborted,  the 
mantle  cavity  being  reduced  to  a  ventral  groove  terminating  in  a 
posterior  cloaca  containing  the  rudimentary  gills,  and  the  outlets  of 
anus  and  nephridia. 

(v) 


vi  POLYPLACOPHORA. 

ler  POLYPLACOPHORA  Blainville. 

The  further  division  of  this  order  into  families  and  genera  will 
be  found  on  page  xxiv. 

The  following  notes  on   the   morphology  of  Chitons  are  mainly 
restri  vaturea  important   from   a  phylogenetic  or  taxonomic 

standpoint;  the  primary  object  of  this  work  being,  of  course,  the 
establishment  of  a  natural  system  of  the  Order. 

Tin.  SHELL. 

The  shell  in  Chitons  consists  of  eight  imbricating  pieces  or  valves, 
bound  together  by  a  leathery  girdle  of  connective  tissue.  The  valves, 
when  freed  of  the  girdle  by  soaking  a  few  hours  in  water,  are  seen  to 
be  of  three  forms:  the  anterior,  (or  "head  valve")  semicircular  in 
outline  its  apex  elevated:  the  intermediate  (sometimes  called 
"  central  "  or  "  median  ")  valves,  squarish  in  shape,  and  the  poste- 
•r  "  tail  valve,"  which  is  like  the  intermediate  valves  with  the 
addition  of  a  sloping  surface  behind  the  apex  or  mucro.  In  struct- 
'he  wives  are  composed  of  two  layer*,  generally  '/////V  different  in 
color  and  texture ;  an  ont'T  AI»/»T,  culled  by  Middendorff  the  tegmeu- 
tum,  •///«/  <in  inner,  the  articulamentum. 

THE  SURFACE  or  i  m   v M.VI.S  (tenmentum)  is  divided  in  nearly 
all  Chitons  into  clearly  defined  or  indistinct  areas.      The  interme- 
diate valves  (fig.  1)  are  divided  into 
lateral  areas  and  a  central  area;  the 
latter  being  subdivided  into  a  dorsal  or 
jugal  tract,  extending  along  the  ridge 
of  the  valve,  and  two  pleura  or  pleural 
tracts,    occupying    the  side-slopes  in 
front  of  the  'Hiirjonal  line  or  rib.      In 
some  forms  (fig.  2)  the  diagonal  line  is 
obliterated,  the  lateral  areas  and  the 
pleural  tracts  being  united  into  a  single 
uniformly     sculptured    expanse,     the 
Fig.  l.    Intermediate  (four t  h) /„/,  ,-,,-y, /, , tr,,f  area,  on  each  side;  the 
valve  of  h<kno,-kit*n  L  dorsal  or  jugal  area  remaining  distinct. 

2, 3,  central  area  (subdivided  int  ,  •         /• 

1   juga,   tract,  and   2f  3|    pleu.  "!'    -"on   IS  characterise   of 

tracts);  4,  5,  lateral  areas.  «>ne -reat  phylum  of  Chitons.    Asa  rule 

Fig.  2.     Intermediate    valve    oftne  head-valve   is  sculptured   all  over 
Atm*tk9(hittt(if/HiWiii  showing  /  like   th«    lateral   areas.     The  posterior 
insertion  plate,  and  Ue    fig.  4)  is  divided  into  a  central 

*alnral  Uni1  and  a  |  .iiva  :  the  former  being 

ar  to  the  area  so  named  in  the  intermediate  valves 


POLYPLACOPHOR  \. 


VII 


and  the  latter  corresponding  clo>ely  in  .-rulptun-  to  the  lateral  areas' 

In  some  genera  the  muero   i>  near  or  at  \\\> 

valve,  and  the  posterior  area  is  then  reduced   to  a    narrow 

altogether  absent  (see  pi.  OL',  li<j>.  17,  I*;.       In  position,  ti. 

may  be  either  anterior  (pi.  -^l  liir.  1*3),  or  media,,  <  pi.  17,  i 

••i«r  (pi.  .VJ,  figs.  22,  I*:!)  ;  and  it  may  be  either  elevat^l    | 
fig.  9-J),  or  depressed  (pi.  39,  fig.  41),  the  last  being  sometime  culled 
a  Hat  or  planate  mucro. 

THE  INNER  LAYER  OF  Tin:  VALVES  (articulament i > i / 1  I-  larger 
than  the  tegmentum,  projecting  in  front  in  two  lobes  called  sntural 
lamince,  which  are  separated  by  a  median  bay,  the  j"ytl  sinus.  At 

the  sides  of  the  intermediate  va! 
and  around  the  semicircle  of  the  end 
valves,  most  Chitons  have  projecting 
plates  called  insertion  plates,  to  whieh 
the  girdle  is  attached.  These  are 
•*»  commonly  cut  into  teeth  by  transverse 
slits.  From  the  slits  to  the  apex  of 
each  valve  inside,  run  slight  grooves 
and  rows  of  pores,  known  as  slit-rays; 
often  they  are  obliterated,  but  in  forms 
having  a  highly  developed  system  of 
sense-organs  in  the  tegmentum,  the 

Figs.  3,  4.    "intermediate   and  PareS   °f  the  ^W*   9Q  rve    &S  D6rve 

posterior  valves  of  Ischnochiton  foramina.  The  teeth  are  sometimes 
conspicuus.  finely  cut  or  crenulated,  (technically 

"  pectinated  ")  between  the  slits ;  and  in  some  forms  the  edges  of  the 
teeth  are  thickened  outside,  or  "  propped."  Fig.  3  represents  the 
interior  of  the  fourth  valve  of  an  Ischnochiton,  showing  the  slits, 
teeth,  insertion  plates,  etc. 

The  tegmentum  is  essentially  cuticular  in  nature.      It  consi>' 
a  chitinous  foundation  substance,  impregnated  with  salts  of  lime. 
It  is  perforated  at  the  surface  by  a  multitude  of  minute,  definitely 
arranged  pores  of  two  sizes,  called  by  Moseley,  the  larger  //<"/<*/"/ 
the  smaller  micropores  (see  pi.  52,  fig.  28,  showing  two  megalopores 
and  many  micropores).      Each  megalopore  leads  into  a  cylindrical 
chamber  which  is  continued  below  into  a  wide  canal,  ffhich  as  it 
penetrates  deeper  toward  the  plane  of  junction  of  tegmentum  and 
articulamentum,  curves  outward  toward  the   girdle-margin  of  the 
former.     On  reaching  the  plane  of  junction  it  joins  a  plexus  of 


viii  POLYPLACOPHOBA, 

main  canals  which  ramify  horizontally  in  this  plane,  and  find  open- 
ing from  tin-  valves  at  the  eaves,  or  outer  bases  of  the  teeth  and 
anterior  sinus.  From  the  sides  of  the  megalopore  chambers  or  from 
the  deeper  plexus  of  canals,  are  given  off  fine  canals  which  perforate 
•••irmmtu:  illy  and  join  the  bases  of  the  micropore  cavities. 

All  of  these  canals  are  occupied  by  fibrous  and  nerve  tissues  con- 
tinued in  from  the  girdle  and  interior.  From  these  ramifications  are 
given  off  l»rum -lies  to  each  megalopore  canal,  in  the  superficial 
chamber  of  which  they  expand  into  obconic  knobs  of  highly  refract- 
ing tissue,  sensory  in  function,  and  in  all  probability  tactile.  These 
knobs  are  calk-d  l>v  Moseley,  megahesthetes ;  they  are  capable  of  being 
somewhat  i'1-otnidi  d  t'nmi  the  mouths  of  the  pores.  The  micro- 
pores  hold  exactly  -imilar  but  smaller  sense-organs,  the  micr (Esthetes. 
These  structures  are  found  in  probably  all  Chitons  ;  but  in  certain 
genera  they  are  subobsolete.  In  others  some  of  the  megalaestlietes 
have  become  transformed  into  eyes.  These  are  connected  with  the 
network  of  soft  tissues,  and  occupy  pear-shaped  cavities  like  the  true 
megabesthetes.  On  one  side  the  bulb  of  the  pear,  more  or  less  near  its 
extremity,  is  closely  applied  to  the  outer  surface  of  the  tegmentum, 
and  here  it-;  wall  is  pierced  by  a  circular  aperture,  the  pupil-like 
opening.  This  opening  covered  by  the  cornea,  the  periphery  of 
which  extends  to  a  considerable  distance  beyond  its  margin  all 
round. 

6  cornea  is  a  concavo-convex,  watch  glass-shaped  lamina,  trans- 
parent, and  calcareous  in  structure,  being  continuous  all  around  with 
the  superficial  calcareous  layer  of  the  tegmentum.  "The  pear- 
shaped  cavity  of  the  eye  in  the  tegmentum  is  lined  by  a  dark  brown 
pigni  mbraiM-  of  a  stiff  and  apparently  somewhat  chitinous 

texture,  which  forms  the  eye  capsule.     This  capsular   membrane 
exactly  follows  the  shape  of  the  eye  cavity,  except  near  the  surface 
of  the  tegmentum,  where  its  margin  curves  inward  beneath  the 
'rming  a  sort  of  iris  and  bounding  the   circular    pupil, 

h  is  of  less  diameter  than  the  cornea.  The  ;ip2rtureof  the  pupil 
is  occupied  by  the  front  surface  of  the  lens.  The  lens  is  perfectly 

parent  and    !  :md  strongly  biconvex.     It  is  filled   in 

behind  the  iris  aperture.  It  is  composed  of  soft  tissue  and  dissolves 
in  strong  acetic  acid  gradually  and  completely,  showing  a  fibrous  dis- 

atructure  in  the  process.  There  is  a  space  between  the  front 
surface  of  the  lens  and  the  cornea. 

'  Within  the  pigm.  nt«  d  tubular  prolongation  of  the  eye  capsule 


POLYPLACOPHORA. 

the  numerous  fine  fibres  composing  the  optic  nenre  beoome  lepai 

from  one  another  and  loose.  Immediately  im<I.--nM-;itli  tlif  n-tm:i  tin- 
fibres  become  still  more  widely  separated,  forming  :m  expansion  of 
fibres.  The  retina  is  formed  on  the  type  of  tliat  of  If,  //./-,  mid  net. 
as  might  have  been  expected,  on  that  of  the  dorsal  eyes  of  Onr Ind- 
ium or  the  eyes  of  Pecten.  The  fibres  of  the  optic  nerve  do  not  pass 
in  front  of  the  layer  of  rods  to  be  distributed  to  them  from  in  front, 
but  are  directed  to  the  rods  directly  from  behind.  The  retina  pre- 
sents a  single  layer  of  short  but  extremely  well  defined  rods,  the 
extremities  of  which  are  directed  toward  the  light.  The  rods  when 
viewed  from  the  surface  of  the  layer  they  compose  are  seen  to  be 
hexagonal  or  pentagonal  in  .outline,  and  each  contains  a  nucleus. 
They  form  a  layer  which  is  concave  toward  the  lens,  there  being  a 
space  between  the  hind  surface  of  the  lens  and  the  concave  face  of 
the  layer." 

Two  eyes  from  the  shell  of  Enoplochiton  (x  40)  are  shown  on  pi. 
52,  fig.  27.  On  pi.  51,  fig.  3  is  seen  an  eye  of  Schizochiton  magnified 
200  diameters,  showing  outside  the  pigmented  eye-capsule,  seen  partly 
through  the  superficial  layers  of  the  tegmentum,  inside  of  which  is 
the  cornea,  and  the  lens,  seen  through  the  cornea. 

The  arrangement  of  the  eyes  varies  in  different  genera,  as  will  be 
seen  by  reference  to  the  systematic  descriptions.  Eyes  are  present 
in  but  one  family  of  Chitons,  the  Chitonidce;  and  in  this  group  they 
are  found  in  all  but  two  genera.  In  these  two  the  megalsesthetes  are 
larger  and  more  regularly  developed  than  in  any  Chitons  of  other 
families.  This  high  development  of  sense  organs  is  associated  with 
the  most  complex  system  of  insertion-plates,  the  completest  form  of 
girdle-armor  and  of  gills  to  be  found  in  the  Polyplacophora.  The 
family  Chitonidce  therefore,  easily  ranks  as  the  consummation  of 
Chiton  development.  Tonicia  or  Acanthopleura  represent  the  utmost 
height  yet  attained  by  the  great  Amphineurous  branch  of  molliisk 
life. 

Theory  of  the  origin  of  valve-structures.  Any  rational  theory  of  the 
development  of  a  structure  must  rest  upon  a  knowledge  of  the  rela- 
tions of  that  structure  to  the  organism  possessing  it  and  to  the 
external  world.  In  discussing  the  genesis  of  the  insertion-plates  of 
Chitons  we  must  therefore  bear  in  mind  (1)  that  the  function  of 
these  plates  is  to  bind  the  valves  firmly  to  the  girdle,  and  (2)  that 
the  entire  force  of  all  impacts  on  the  valves  is  transmitted  to 
plates,  which  are  separated  from  the  solid  surface  supporting  the 


X  POLYPLACOPHORA. 

:il  Ity  a  thin  pad  of  girdle.  It  is  to  the  direct  effect  of  impacts 
and  -  ntinnally  l>rought  to  boar  upon  the  growing  edges  of 

these  plates,  that  their  development  is  duo,  in  precisely  the  same 
manner  that  the  enlarged  joints  of  a  laborer's  hand  are  the  result  of 

:m  pacts  and  strains  to  which  they  have  been  subjected.  All 
Chitons  which  live  in  situations  exposed  to  the  buffeting  of  the  surf, 
possess  highly-developed  in>ert  ion-plates,  which  are,  moreover,  in 
nearly  every  cases.  :  >u<ly  corrugated  for  the  more  effective 

grasp  of  the  girdle.    Examples  are  the  groups  Enoplochiton  and 

tomura  on  the  west  coast  of  South  America,  Acanthopleura  in 
the  West  In. li<->  and  el-ewhere,  JJn/ojiluira  in  Australia  and  Japan, 
all  rmiarkable.forthe  great  development  of  strong,  rough  insertion 
plates,  and  equally  for  the  very  exposed  situations  in  which  they 
live,  »t'ten  subjected  in  the  full  force  of  the  surf.  It  is,  of  course,  the 
belief  of  the  writer  that  characters  acquired  by  the  action  of  natural 
forces,  acting  upon  many  generations,  become  hereditary  ;  but  in 
tural  selection  "  no  doubt  has  had  a  certain  consider- 
able effect,  although  the  process  has,  I  believe,  been  mainly  one  of 
selection  from  definite  variations  produced  by  the  mechanical  causes 
described  above,  not  selection  from  indefinite  variations  in  all  direc- 
tions. 

On  the  other  hand,  forms  living  in  less  exposed  stations,  such  as 

ath  stones  at  or  below  low  water,  have  thin,  smooth  insertion 
plates  (IMfioeAifoft)  etc) ;  and  at  great  depths,  where  the  motion  of 
the  water  and  its  power  of  transporting  pebbles  or  stones  is  reduced 
to  a  minimum,  and  where  therefore  the  valves  of  the  Chitons  are  not 

•  t  to  impacts  or  strains  from  without,  the  species  are  found  to 
be  entirely  without  insertion  plates.  This  excessively  weak  organ iza- 
tion  has  been  transmitted  unchanged  from  the  Paleozoic  Chitons, 
all  of  which  lacked  insertion-plates;  and  it  is  a  significant  fact  that 
[Ofl  typ,-  lias  been  able  to  exist  to  the  present  time  only  in 
deep  water,  where  the  forces  which  I  believe  to  have  moulded  the 
modern  Chitons  do  not  act,  and  where  competition  in  the  life-struggle 
is  less  severe  than  in  the  shallows. 

In  this  connection  the  case  of  J't'U-l/Jwra  (PlacojiJinroj,*!*)  ntlnn- 
tica  shoul  i      Thi>  species  was  dredged  off  New  England  in 

•ni\\n  tins., — depths  beyond  the  limit  of  the  penetration  of  li-ht, 
and  of  course  far  beyond  the  reach  of  appreciable  water  movement, 

r  l>y  currents  or  surface  disturbances.  The  conditions  therefore 
demand  no  stronger  apparatus  for  the  attachment  of  the  valves  to 


POLYPLAOOPHO1  XI 

the  girdle  than  is  possessed  l>y  Lepidopkurui ;  ami  in   fart  \\o  find 
that  its   insertion   plates  are  reduced  to  very   >hort  Mmm 
anterior  "  teeth  "  arc  small,   low,   unevenly  notched,  and  not    n« 
as  long  as  the  overhanging  eaves.    It  is  only  n<-r. 
that  the  genus  Ptaxipkora,  tin-  nearest  ally  of  I'/m-ojJi" 
remarkable  for   the    length   of  its  strong,   regularly   slit  insertion 
plates.      The  same  is  true  of  the  entire  family  Mnjmli'n^r,  to  whieh 
these  genera  belong.      In  Pln<'ophorop«i*  u/A/.//.//m  wo  have,  there- 
fore, a  member  of  a  family  of  littoral  Chitons,  which  by  descent  into 
the  abyssal  region  has  partially  lost  by  retrogressive  development 
through  disuse  the  characters  originally  evolved  to  fit  the  ancestral 
forms  for  existence  in  the  littoral  zone.     Further  deep  sea  researches 
will  probably  reveal  other  cases  of  degeneration  along  the  lines  here 
indicated  ;  and  it  is  not  impossible  that  forms  as  destitute  of  insertion 
plates  as  the  genus  Lftpidopleurus  have  been  produced  from   hi. 
types  by  retrogessive  evolution ;  but  there  is  at  present  no  evidence 
of  the  existence  of  such  forms. 

THE  GIRDLE. 

This  organ  variously  called  ligament,  zone,  or  girdle,  is  a  baud 
of  connective  and  muscular  tissues  extending  around  the  valves,  the 
edges  of  which  are  imbedded  in  it.  The  surface  of  the  girdle  is 
variously  clothed  with  scales,  spines,  haiis  or  spicules,  or  is  naked. 
The  armor,  whether  of  spines,  scales  or  hairs,  consists  of  a  chiti- 
nous  foundation  more  or  less  infiltrated  with  lime.  The  girdle- 
appendages  vary  greatly  in  development  among  closely  allied 
species;  but  the  general  type  of  covering  is  a  moderately  constant 
generic  character.  In  some  forms  the  girdle  encroaches  upon  or 
entirely  covers  the  valves.  In  some  genera  having  a  posterior 
sinus  in  the  tail-valve,  the  girdle  has  a  corresponding  sinus  or  slit ; 
in  others  it  has  no  sinus,  but  in  life  is  always  curved  upward  into  a 
posterior  conduit,  serving  for  an  outlet  for  the  anus  and  gills. 

In  some  forms  having  hairy  or  spiculose  girdles,  the  hairs  or 
spicules  are  gathered  into  tufts  or  groups  at  the  sutures  (i.  e.  lateral 
points  of  junction  between  valves),  and  around  the  anterior  valve  ; 
issuing  from  pits  or  pores  at  those  places  (see  pi.  5,  fig.  97).  In 
their  incipient  stage,  these  sutural  tufts  are  merely  the  gathering 
together  of  two  or  several  of  the  ordinary  surface  hairs:  in  their 
full  development  they  are  dense  clusters  of  long  spicules  ;  and  in 
their  decadence  only  a  small  pit  or  pore  remains.  The  presence  of 


Xll  POLYPLACOPHOR  \ . 

pores  or  tufo  has  been  considered  by  systematists  a  character  of 
great  value;  but  not  with  justice.     The  fact  is  that  at  least  three 

H  in   the  development  of  Chitons  has  this  feature  appeared 

independently  ;  first  in  the  genus  Hemiarthrum  of  Lepidopleuridce, 

form  having  a  pore  at  each  suture,  and  six  around  the  head 

valve;  second  in  Call;  /  (culminating  in  Mopaliidci)  where 

pores  are  excessively  inconstant,  and  the  number  around  the 
head  valve  indefinite  (0-6)  ;  and  for  the  third  time  in  Acantho" 

"he  and  its  derivative  l'nj/>foplacid<je,  where  the  number  of 
tufts  around  the  head  valve  is  invariably  four,  in  genera  having 
pores.  Every  genus  (if  it  has  more  than  one  or  two  species)  con- 
taining pore-bearing  species,  includes  also  forms  in  which  the  pores 
or  tufts  have  become  subobsolete  or  entirely  lost.  In  the  genera  of 
Mopaliirla,  the  pores  are  occasionally  not  of  specific  importance ; 
and  the  same  is  true  of  Amu-nl<i. 

•  gene*i*  of  *,</,//•<//  tufts  is  not  beyond  the  reach  of  theory.  I 
believe  them  to  be  the  direct  result  of  over-nutrition  of  the  girdle 
at  the  sutures,  caused  by  its  greater  mobility  at  those  points.  It  is 
»us  that  every  motion  of  the  valves  must  cause  a  flexure  of  the 
girdle  at  the  sutures;  this  brings  a  greater  flow  of  nutriment  to  the 
•timulated  portion,  in  this  case  a  narrow  strip,  resulting  in  a  more 
exuberant  growth  there. 

HEAD,  FOOT,  GILLS,  ETC. 

Viewed  ventrally  Chiton  presents  a  fleshy  foot,  similar  to  that 
the  Gastropoda  (pi.  34,  fig.  68).     Separated  from  this  by  a  sinus  is 
the  ht-ad.  with  the  mouth  in  the  center  of  the  disk,  which  is  gen- 
erally surrounded   in  front  by  a  lappet  called   by   Carpenter  the 
There  are  no  tentacles  or  eyes.     The  inner  edge  of  the 
ventral  surface  of  the  girdle  may  be  regarded  as  the  mantle.     It  is 
sometimes  fringed  or  produced  into  finger-shaped  processes  in  front. 
The  gills  consist  of  a  row  of  triangular  branchial  plumes  extending 
near  the  tail  forward  from  a  fourth  to  the  entire  length  of  the 
The  anus  is  median  and   posterior,    generally  opening  on 
*  Pal)illa  -  nephridial  openings  are  in  the  gill-groove,  at  the 

:iml  in   front  of  the  anus.     The  two  genital  openings  are   in 
front  of  the  nephridial  orifices. 

radula  has  been  investigated  by  Loven,  Sars,  and  especially 
ill,  who  describes  the  teeth  as  follows :  "  In  all  Chitons  exam- 
ined there  is  a  simply  cuspid  rhachidian  tooth,  and  on  each  side  a 


POLYPLACOPHORA.  XI II 


translucent  minor  lateral  of  varying  form  ;    :i  major   lateral   la- 
than  any  of  the  other  teeth,  with  a  conspicuous  black  cusp,  which 
may  have  from  one  to  four  denticles ;  two  boss-like  or  thick' 
uncinal  plates  of  irregular  shape  ;  a  twisted  spatulate  uncinal,  and 
three  scale-like  or  slightly  thickened  external  uncini.     With  the 
exception  of  the  spatulate  uncinus  (which  is  aborted  in  a  very  few 
species)  none  of  the  uncini  are  much  raised  above  the  plane  of  the 
odontophore,  and  none  present  any  characters  of  importance. ' 

Dall  has  figured  and  described  the  dentition  of  species  belonging 
to  over  half  of  the  genera  and  subgenera  recognized  by  Carpenter 
including  all  of  the  main  types.  He  concludes  that  as  yet  no  char- 
acters affording  grounds  for  even  generic  distinctions  can  be  found 
in  the  teeth,  which  exhibit  a  most  surprising  uniformity  throughout 
the  entire  group.  The  dentition  of  a  number  of  genera  not  exam- 
ined by  Dr.  Dall  has  been  worked  out  by  the  writer,  but  without 
result  as  far  as  the  discovery  of  structures  of  taxonomic  value  is 
concerned.  It  is  evident  that  while  some  minor  features  of  the 
dentition  are  characteristic  of  groups  founded  upon  other  charac- 
ters, we  need  expect  little  assistance  in  larger  questions  of  group 
affinities  from  the  further  investigation  of  this  organ. 

The  gills  are  "posterior"  or  short  in  the  lower  Chitons,  the 
Lepidopleuridce,  and  also  in  the  lowest  Ischnochitonidce,  and  in  most 
genera  of  the  phylum  Acanthochitidce—Cryptoplacidce,  which  arose 
from  an  early  Ischnoid  stock.  All  other  Chitons,  including  the 
higher  Ischnochitonidce,  the  Mopaliidce  and  the  Chitonidw,  have 
"  ambient "  or  long  gills. 

TERATOLOGY. 

The  occurrence  of  six-  and  seven-valved  Chitons  has  been  noted 
as  early  as  the  time  of  Linnaeus.  It  is  likely  that  the  six-valved 
were  artificial  fabrications,  although  a  certain  number  may  perhaps 
be  traced  to  incorrect  drawings.  Most  seven-valved  specimens  are  due 
to  the  soldering  together  of  two  valves  in  consequence  of  some  injury. 
This  is  not  uncommon,  a  number  of  cases  having  come  under  my 
observation.  Individuals  actually  seven-valved  are  known  to  occur, 
although  they  are  far  from  common.  The  writer  has  examined  many 
thousand  Chitons,  but  has  seen  only  two  normally  7-valved  examples. 
One  of  these  is  figured  on  pi.  64,  fig.  67  ;  and  as  may  be  seen,  it  is  in 
no  respect  abnormal  save  in  the  want  of  one  central  valve,  and  the 
consequent  lengthening  of  the  others.  There  is  absolutely  no  trace 


of  the  missing  valve.  The  absence  of  a  valve  produces  no  striking 
change  in  the  general  appearance  of  the  animal,  and  it  would  be 
easy  to  pass  one  by  among  a  quantity.  These  considerations  incline 
me  to  think  that  abnormalities  in  the  valves  may  be  less  rare  than 
•opposed. 

Injuries  to  the  girdle  often  produce  more  or  less  irregular  growth. 

-pecies  having  large  girdle-scales,  such  as  Chiton  s.  dr.,  or  the 

large-scaled   Ischnochitons,  the   loss  of  scales  is  repaired   by   the 

DJured  area  of  scales  much  smaller  in  size,  giving 

it  a  singular!  \  !  appearance. 

Co  i  \  A  ITON  OF  CHITONS. 

Chitons  may  be  looked  for  on  all  but  sandy  coasts ;  on  these  they 

are  very  rare.  Some  species,  like  Nutiallina,  Enoplochiton*  Acantho- 

'  tc.,  are  found  upon  the  exposed  rocks  at  or  near  high  tide  ; 

others  like  most  7  ton*,  live  under  stones  between  tides  or  at 

lowest   water;  Km    it   is  only  by  the  use  of  the  dredge  that  any 

roach  to  a  full  representation  of  the  Chiton  fauna  of  any  locality 

can  be  obtained.  e  dredging  outfit  is  required,  how- 

•  ver  nine-tenths  of  the  species  being  vegetable  eaters,  live 
in  the  littoral  (including  the  laminarian  and  coralline)  zone,  and 

generally  be  taken  in  25  fms.  or  less  depth  ;  although  num- 
bers of  species  extend  their  rani:e  to  or  beyond  the  100  fm.  line,  and 
a  few  (the  genera  Lepidoplewrut  and  Hanleya  only)  live  in  the  cold 
and  dark  abyssal  region. 

hint  knife  is  useful  to  the  collector  in  detaching  Chitons  from 

rocks  etc. ;  and   the  specimens  before  they  have  time  to  curl 

nelves  up,  should  be  placed  flat  on  a  narrow  strip  of  smooth 

wood  like  a  ruler  or  lath  well  wetted  with  salt  water,  and  bound 

down  l.y  windin-  with  s..ft  twine  or  randle-wicking.    This  will  keep 

them  in  a  natural  position  until  the  tissues  are  relaxed,  when  they 

may  be  placed  in  alcohol,  or  cleaned  by  cutting  away  the  foot  and 

viscera.   If  this  precaution  is  not  taken  they  are  apt  to  curl  up  in  a 

shape  which  renders  them   alm^t  useless  for  dissection  or  for  cab- 

-pecimens,  for  they  will  break  rather  than  flatten  out.    A  large 

l»er  maybe  thus  set  on  a  single  stick.     If  th.-y  curl  up  before 

•  -  t.  it  is  best  to  put  them  in  a  pan  of  salt  water,  where 
will  eventually  straighten  out,  if  al 

HIM. .iii.  AI.  NOTES  ON  i  in   I.ii  i  HATURE  OF  CHITONS. 

w  species  of  Chitons  were  known  to  writer.-,  upon  shells 


POLYPLAOOPflORA, 

prior  to  1758,  the  date  of  LINN.KI;*'  Truth  Kdition,  in  which  f,,ur 
species  were  described.  By  the  addition  of  the  form-  ,,f  northern 
Europe,  this  number  is  increased  to  nine  in  the  twelfth  edition  of 
the  Systema.  From  this  time  on,  large  numbers  of  ChitODfl  found 
their  way  into  English  and  Continental  collections,  and  were  figured 
in  the  works  of  Chemnitz  and  others.  Linnc  classed  the  Chitons 
with  the  Cirripeds  and  Pholads,  before  the  bivalves  ;  and  this  sys- 
tem persisted  in  conservative  conchological  works  during  the  first 
few  decades  of  the  present  century.  In  1797,  SPENGLER,  a  Danish 
naturalist,  published  a  good  monograph  upon  Chiton  ;  but  little  real 
progress  was  made  toward  a  right  appreciation  of  the  rank  of  the 
group,  and  the  establishment  of  a  natural  classification,  until 
BLAINVILLE  in  1816  (Bull.  Philom.)  separated  them  from  the 
other  mollusks  as  a  Class,  to  which  he  gave  the  name  Polyplaxiphora. 
In  1825,  Blainville  published  the  article  upon  Chitons  in  the  Die- 
tionnire  des  Sciences  Naturelles.  In  this  work  an  excellent  descrip- 
tion of  the  entire  organization  is  given,  the  parts  of  the  valves  are 
definitely  named,  and  the  characters  upon  which  the  divisions  of 
the  genus  must  be  based  are  stated.  The  extraordinary  insight 
and  genius  of  the  French  malacologist  are  manifest  throughout 
the  systematic  and  structural  part  of  this  paper ;  but  the  descrip- 
tions of  species,  being  unaccompanied  by  illustrations,  have  been 
less  useful.  QUOY  &  GAIMARD,  in  1834,  gave  an  excellent 
account  of  the  species  collected  during  the  voyage  of  the 'Astrolabe' ; 
following  the  general  lines  laid  down  byde  Blainville.  Since  1834, 
no  systematic  work  on  Chitons  of  more  than  local  interest,  has  been 
published  upon  the  continent  of  Europe. 

In  England,  considerable  species-work  upon  Chitons  was  done 
prior  to  1829,  but  all  upon  strictly  Linn sean  lines.  In  the  year 
1829,  Rev.  LANSDOWN  GUILDING,  residing  in  St.  Vincent,  West 
Indies,  wrote  a  valuable  paper,  in  which  he  recognized  five  genera : 
Chiton,  Acanthopleura,  Phakellopleura,  Chitonellus,  Cryptoconchu* ; 
defining  each  in  an  acceptable  manner.  Shortly  after  this,  the  discov- 
eries of  Frembly,  Cuming  and  others,  threw  a  multitude  of  new 
and  handsome  species  into  the  hands  of  the  London  conchologists. 
BRODERIP  and  SOWERBY  described  most  of  the  .  novelities  in  the 
P.  Z.  S.,  1832-1834,  and  in  the  Mag.  of  Nat.  Hist.,  1840 ;  and  Sow- 
erby  illustrated  them  in  the  Conchological  Illustrations,  published  a 
little  later.  These  authors  knew  nothing  of  internal  characters, 
confining  their  attention  to  the  superficial  features  of  the  shell  only. 


xvi  POLYPLACOPHORA. 

The  same  is  true  «  i:,  who  in  1847,  published  a  monograph 

lining  189  species  in  the  Conchologia  Iconica.  The  figures 
of  Sowerby  and  Reeve  are  generally  good  ;  but  they  ignore  inter- 
nal characters,  and  tlu-ir  «1< '.-mptimis  are  totally  inadequate.  J.  E. 
GRAY,  in  1847,  (Ann.  Mag.  Nat.  Hist.,  July-August, and  P.  Z.  S.), 
proposed  a  system  of  classification  of  Chitonidce,  embracing  many 
new  genera,  but  largely  based  upon  Blaiuville's  article  of  1825. 

s  system  is  as  follows : 

V,  n-it  limit  >imj  pores  or  tufts  ofsjtiiic*  <>n  the  sides. 
A9  7  • 'in 1 1  posterior  valves  divided 

'•>  several  '  'I  of  the  cent  ml  -mli-e*  into  two  lobes. 

a.  Containing  Chiton,  Tonicia,  Acanthopleura,  Schizochiton. 

b.  Containing  Corcphium,  Plaxiphora,  Onithochiton,   Enoplo- 
clii- 

['-.  Radsia,  Callocliiton,  Ischnochiton,  Leptochiton,  subsequently 

a-l.lrd  by  Gray.] 

B.  The  plate  of  insertion  of  all  the  valves  with  only  a  single  notch  on 
The  valves  more  or  less  covered ;  the  hinder  valve 
I  [dales  of  insertion  (as  in  the  central  valves'),  with 
only  a  single  notch  <»i  cat-h  side,  and  a  concave  sinuosity  below. 
a.  Contain.-  M<»palia.  Katharina,  Cryptochiton. 
//    Mi   •  '•  >/  >t!i  <i  series  of  pores  (each  furnished  with  a  tuft  of  spine*) 
on  each  side.    The  plates  of  insertion  of  all  the  valves  with  only  a  sin- 
gle notch  on  each  tide  which  is  sometime*  rudimentary. 

a.  Contains   Cryptoconchus,  Amicula,  Acauthochites,   Chiton- 
ell 

Some  inconsiderable  transpositions  and  additions  were  made  by 
Gray  in  e,  1857.      This  classification  is  accepted  by  H.  & 

A.  Adams,  in  their  Genera  of  Recent  Mollutca,  1858;  the  two  pri- 
mary «livi-i<  dig  being  regarded  as  subfamilies  (  Chitonince  and  Crypto- 
plar,  i.  ni.  The  species  of  their  lists  in  very  many  cases  do 

not  belong  to  the  genera  to  which  they  are  assigned,  the  lists  having 
been  compiled  without  regard  to  the  characters  of  the  insertion 
plates.  The  main  defects  of  this  system  are  the  greatly  exaggerated 
importance  given  to  the  development  of  girdle-pores,  and  the  imper- 
fect apprehension  of  the  features  of  the  insertion  plates.  Some 
yean  before  the  date  of  Gray's  last  paper,  J.  R.  Sm  in  i  \\ORTH, 
an  Englishman  by  birth,  Init  nvidi-nt  in  Switzerland,  studied  the 
Chitons  carefully  in  the  light  of  Gray's  earlier  paper,  and  published 
i-  of  the  group  (Bern.  Mittheil,  1853),  making 
a  number  of  decided  improvements  in  classification. 


POLYPLACOPHORA.  xvii 

At  the  same  time  that  Gray  published  his  first  <-.s.say,  Dr.  A.  TH. 
VON  MIDDENDORFF  proposed  an  elaborate  scheme  of  classification, 
in  an  extensive  work  upon  the  Siberian  Chitons.  His  divi.-ion-  \v«-r«- 
based  upon  (1)  the  entirely  internal  or  partly  exposed  condition  of 
the  valves,  and  position  of  the  apex  of  each,  (2)  degree  of  immer- 
sion, indicated  by  the  contiguity  or  separation  of  the  exposed  part 
of  the  valves,  (3)  comparative  width  of  the  girdle,  and  (4)  presence 
or  absence  of  girdle-pores.  This  classification  although  worked  out 
with  vast  industry,  is  a  distinct  retrogression  from  the  stand  taken 
by  de  Blainvillein  1825.  MiddendorfF however,  did  excellent  work 
upon  the  anatomy  of  the  Chitons  in  this  publication.  His  arrange- 
ment is  as  follows : 
Genus  Chiton  L. 

(1)  Subgenus  Cryptochiton  Midd.  (C.  stelleri). 
(1)  Subgenus  Phcenochiton  Midd. 
(2)  Section  Dichachiton  Midd. 

(3)  Subsection  Symmetr  ogephyr  us  Midd. 

(a.)  Poriferi,  Ch.  (Symmetr.)  monticularis  Q.  [=Crypto- 

conchus.] 
(ft.)  Apori,  Ch.  (Symmetr.)  vestitus,  pallasi,  amiculatus 

[— Amicula.] 
(3)  Subsection  Afnetrogephyrus  Midd. 

(a.)  Poriferi,  Ch.  fasciatus  Q.,  larvseformis  Blv.  [=Cryp- 

toplax.] 

(6.)  Apori,  Ch.  Isevis  Lm.  [— Cryptoplax.] 
(2)  Section  Hamachiton  Midd. 
(3)  Subsection  Platijsemus  Midd. 

(a.)  Poriferi,  Ch.  zelandicus,  emersoni,  biramosus,  etc.,  [— 

Acanthochites,  Plaxiphora,  etc.] 

(6.)  Apori,  Ch.  submarmoreus,  tunicatus,  alatus,  incisus, 
wosnessenskii,  [— Tonicella,  Katharina,  Ischnochiton, 
Mopalia,  etc.] 
(3)  Subsection  Stenosemus  Midd. 

(a.)  Girdle  hairy,  Ch.  marmoreus,  lineatus,  brandti,  mercki, 

etc.,  [^Tonicella,  Schizoplax,  etc.]    , 
(6.)    Girdle  finely  squamose,  Ch.  ruber,  albus,  cinereus, 

etc.,  [=Trachydermon,  Lepidopleurus.] 
(c.)  Girdle  coarsely  scaly,  Ch.  mertensii,  etc.,  [— Lepido- 

zona.] 
MiddendorfFs  names  being  published  simultaneously  with  Gray's, 


xvi  li  POLYPLACOPHORA. 

iot  be  given  priority,  save  in  the  case  of  Cryptochiton ;  the  other 
groups  are  all  incongrous  assemblages. 

rp.ni  tlii-  time,  no  \\ork  of  importance  was  done  on  Chitons 
until  ixr>3,  when  PHII.H'  P.  CAIMT.NII  it  (born  in  Bristol,  England, 
in  1*1  •».  died  at  Montreal,  Canada,  1877)  published  a  catalogue  of 
the  V  rican  f..rm-  Urit.  Asso.  Rep).  This  was  followed  by 

-  upon  the   California!!    and   Atlantic   Chitons,   and 
finally  by  the  preparation  of  a  monograph  of  the  entire  group.     In 

work  upon  this  great  undertaking,  Dr.  Carpenter  examined 
critically  the  Cumiugian  and  British  Museum  collections,  contain- 
ing most  of  the  types  of  Broderip,  Sowerby,  Gray,  Reeve  and  H. 

.•ii5»;  and  besides,  nearly  every  collection  of  any  size  in  England 
and  America,  including  thoM  of  A.  Adams,  Angas,  Dr.  A.  A.Gould, 

comb,  Jay,  Haines,  the  State  of  California,  the  Smithsonian 
Institution,  Museum  of  Comparative  Zoology,  etc.  The  information 
gained  from  the  examination  of  this  great  amount  of  material  was 
in  process  of  re-arrangement  at  the  time  of  his  death,  in  1877,  that 

ing  to  the  Leptoidea  and  Ischnoidea  being  practically  com- 
pleted. A  vast  amount  of  work  had  been  done  upon  the  other 
groups,  but  his  studies  of  them  were  far  from  finished.  A  large 
number  of  drawings  had  been  prepared  under  Dr.  Carpenter's 
direction,  mainly  by  Messrs  Emerton,  Foord,  and  Smith.  The 
whole  «»f  this  J/.S.  being  devised  to  the  Smithsonian  Institution, 

\VM.  II.  DALL  published  (Proc.  U.  S.  Nat.  Mus.  1881,  p.  283- 
7  tfie  genera  of  Chitons,  giving  Carpenter's 

complete  classification,  and  brief  diagnosis  of  the  new  groups, 
of  the  Carpenterian  names  therefore  date  from  this  time; 
although  in  1873  a  large  part  of  them  were  included  by  Carpenter 
in  u  table  printed  by  the  Smithsonian  Institution,  showing  the 
characters  of  the  "  Regular  Chitons.  "  The  fact  that  the  distribu- 
tion of  this  table  was  limited  to  Carpenter's  personal  friends  and 
correspondents,  that  it  was  never  advertised  or  offered  for  sale,  was 
not  sent  to  most  (if  any)  public  scientific  libraries  nor  noticed  in 

i  tific  journals,  prevents  ug  from  dating  his  names  from  the  time 

publication. 

The  following  table  shows  the  Carpenterian  classification  in  full. 
The  group  and  family  names  given  by  DALL  in  1889  ('Blake" 
Gastropoda)  are  added  in  parenthesis. 


Order  POLYPLACIIMIOL'A  (Polyplaoophora  Dull;. 

Section  I. — Chitones  regulares    BoOHITON]  \  I'ull;. 

Head  and  tail  plates  similarly  artinilat* •<!. 

A.  LEPTOIDEA  (Leptochitonidot  Dall 
Insertion  plates  obsolete  or,  if  present,  unslit. 

(Extinct  forms.) 

Jlt'lininthochiton  Salter.  Pterochiton  Cpr. 

Qryphochiton  Gray.  /  Loricites  Cpr. 

Choncchiton  Cpr.  Probolwum  Cpr. 

Priscochiton  Billings.  Cymatochiton  Dall. 

(Recent  forms.) 
Leptochiton  Gray.  Hemiarthrum  Cpr. 

Deshayesiella  Cpr.  Microplax  Adams  and  An  gas. 

Hanleyia  Gray. 

B.  ISCHNOIDEA  (Ischnochitonidse  Dall). 
Insertion  plates  sharp,  smooth,  fissured  ;  with  eaves. 

*No  pores  on  girdle. 
Trachydermon  Cpr.  Ischnochiton  Gray. 

Trachyradsia  Cpr.  Stenoplax  Cpr. 

Callochiton  Gray.  Stenoradsia  Cpr. 

Stereochiton  Cpr.  Ischnoplax  Cpr. 

Tonicella  Cpr.  Heterozona  Cpr. 

Schizoplax  Dall.  Ischnochiton  s.  s.  Cpr. 

Leptoplax  Cpr.  Ischnoradsia  Shuttleworth. 

Chcetopleura  Shuttleworth.  Lepidopleurus  Cpr. 

Manger ella  Cpr.  Lepidoradsia  Cpr. 

Spongiochiton  Cpr.  Callistochiton  Cpr. 

**With  girdlepores. 

Callistoplax  Cpr.  Ceratozona  Dall. 

Angasia  Cpr.  Pallochiton  Dall. 

Neivcombia  Cpr. 

C.  LOPHYROIDEA  (Lophyridce  Dall). 
Insertion  plates  broad,  pectinated,  projecting  backward. 
Chiton  Linne.  Eudoxochiton  Shuttleworth. 

Radsia  Gray.  Craspedochiton  Shuttleworth. 

Tonicia  Gray. 
Fannettia  Dall. 

D.  ACANTHOIDEA  (Acanthopleuridce  Dall). 

Insertion  plates  thrown  forward. 
*Plates  broad,  pectinated  (A  lophyroidea). 
Sclerochiton  Cpr. 

**Plates  sharp,  grooved  outside  (A  typica). 
Acanthopleura  Guilding.  Cwphium  <  Jray. 

Lucilina  Dall.  Francisia  Cpr. 


XX  POLYPLACOPHORA. 


***Plates  sharp,  smooth  (A.  /. 
l)iimplax  Cpr.  Xiiff'illui'i  Cpr. 

Mi'ldcwlorjia  ('|>r-  !»r. 

Beaiiella  Dall.  /V/«/(v//oy»A  //ra  Guild!  ng. 

Section  II.  —  Chitones  irregulares  (OPSICHITONIA  Dall). 
Tail  plate  abnormal  or  with  a  sinus  behind. 
E.  SCHIZOIDEA  (Schizochltonidce  Dall). 

Tail  valve  fissured. 

a  H.  and  A.  Adams.  ochiton  Gray. 

Aulacochiton  (Shuttleworth)  Cpr. 

F.  l*i..\«  im<>i:<uin:A  (Placophoridce  Da\\). 
Tail  valve  unslit,  internally  ridged,  mucro  nearly  terminal. 
Enoplorhiton  Gray.  Fremblya  H.  Adams. 

Ornithnchiton  Gray.  Euplaciphora  Shuttleworth. 

Plncifthora  Gray.  Guildingia  Cpr. 

G.  MOPALOIDKA   (Mopaliidto  Dall). 

Tail  valve  with  posterior  sinus  and  one  slit  on  each  side. 
iii  (  »ray.  Macmidrellus  Cpr. 

FlaeqphoreUa  Cpr.  Stectoplax  Cpr. 

Rather  inn  (  Jray.  Notoplax  H.  Adams. 

thochiton  (I^each)  Herrm. 

H.  CRYPTOIDEA  (Amiculidce  Dall). 

With  double  sutural  laminae. 

'foconchus  Blainville.  Chlamydochiton  Dall. 

Amicula  Gray.  Cryptochiton  Gray  &  Middendorf. 

Amicula  s.  s.  Dall. 

I.  CHITONELLOIDEA  (Cryptoplacidce  Dall). 
Tail  plate  funnel-shaped.     Laminse  thrown  forward. 
Chitoncllus  Blainville.  Choneptax  Cpr. 

Cnjptoplax  Gray.  CMtoniteui  Cpr. 

There  can  be  no  doubt  that  Carpenter's  classification  is  a  great 
advance  upon  that  of  Gray.  It  will  be  noticed  that  the  primary 
division  of  the  family  is  into  two  great  groups:  (1)  Chitons  having 
the  head  and  tail  valves  similarly  articulated  with  the  girdle,  and 
(2)  those  having  them  strongly  dissimilar.  These  two  great  groups 
were  early  recognized  by  Carpenter,  and  called  respectively  Regu. 
lar  and  Irregular  Chitons. 

DALL,  in  his  Report  on  the  Chitons  of  Alaska  (1878),  accepts  the 
Carpenterian  classification,  correcting  it  in  some  details,  notably  in 
the  arrangement  of  the  Amiculoid  forms.  In  the  same  year  he 
published  an  extensive  and  extremely  valuable  paper  upon  the  den- 


POLYFLAOOPHORA. 

tit  ion  i»t'  the  Ljmup,  ^ivini:  figure-  ;m<l  de~eripti.in-<  of  the  radii  Ire  of 
speeies  representing  a  majority  of  tin-  'jenna  of  (  hit. .us.      In  1889, 

hall  proposed  the  Buperfamily  aod  family  Dames  quoted  In  pi 

thesis  in  the  above  table. 

The  writer  j imposes  to  show  in  the  eoiir~e  of  this  work,  that  th«- 
primary  division  into  Regular  and  Irregular  forms  is  not  funda- 
mental, the  Irregular  group  heini^  polyphyletlc,  consisting  of  g<  i 
derived  from  several  totally  distinct  stocks.  With  the  exception  of 
the  Leptoidea  (Leptochitonidie),  Ischnoidea  (Ischnochitonidse)  and 
Chitoiir/fnidea  (Cryptoplaeida-),  all  of  the  family  groups  of  Carpen- 
ter and  Dall  require  dismemberment. 

DR.  PAUL  FISCHER,  in  his  Manuel  de  Conchyliologie,  1885,  adopts 
the    Carpenterian    arrangement,    with    some    transpositions,    hut 
reduces  the  generic  names  of  former  authors  to  the  rank  of  sub- 
genera  and  sections.     His  scheme  is  as  follows.     The  Carpenterian 
equivalents  being  given  in  brackets,  a  glance  at  the  above  table  will 
show  what  groups  were  included  by  Fischer. 
Family  CHITONID^E. 
Genus  HOLOCHITON  Fischer,  1885  [=Leptoidea  Cpr.] 

Subgenus  Eochiton  Fischer,  1885  [^Palaeozoic  Leptoidea]. 
Genus  CHITON  Linn.  [Includes  Ischnoidea,  Lophyroidea,  Acanthoi- 
dea  of  Cpr.]. 

Subgenus  Tomochiton  Fischer,  1885  [Includes  the  Ischnoidea  and 
Aeanthoidea  ischnoidea  which  lack  girdle  pores]. 

Subgenus  Porochiton  Fischer,  1885  [Includes  the  Ischnoidea  and 
Aeanthoidea  ischnoidea  which  have  girdle  pores]. 

Subgenus  Chiton  s.  s.  [==  Lophyroidea  of  Cpr.]. 

Subgenus  Acanthopleura  Guild.  [= Aeanthoidea  typica  Cpr.]. 
Genus  ANISOCHITON  Fischer,  1885  [Includes  Schizoidea,  Placipho- 

roidea,  Mopaloidea  of  Cpr.]. 

Genus  CHITONELLUS  Lam.  1819  [=Chitonelloidea  Cpr.]. 
Genus  DIARTHROCHITON  Fischer,  1885  \=Cryptoidea  Cpr.]. 

It  will  be  noticed  that  Fischer  ignores  the  law  of  priority  in  the 
use  of  generic  names.  His  classification  is  not  otherwise  very  different 
from  Carpenter's,  except  that  he  reduces  the  genera  of  Gray  and 
Carpenter  to  the  rank  of  sections. 

M.  A.  T.  DE  ROCHEBRUNE,  in  several  papers  upon  Chitons,  pub- 
lished from  1881  to  1889,  has  classified  the  group  in  various  ways, 
the  principal  schemes  being  given  below.  It  is  necessary  to  give  in 
brackets  the  equivalents  of  Rochebrune's  genera,  in  order  to  under- 


XXII  POLYPLACOPHORA. 

stand  what  hi*  family  groups  really  mean. 

In  (2)  iv,  1881,  Rochebrune  presents 

the  following  arranp-ment: 

Family  ATAN m<><  HIT.E  Rochebr.,  genus  Acanthochites  Risso. 

1 'an illy  ( '11  i;  i  Rochebr.,  genus  Chcetopleura  Shutt,  spe- 

<gas  Cheni. ;  and  genus  Acanthopleura  Guild. 

Family  ('IHTONID.K  Gray,  genus  Tonicia  Gray,  Lepidopleurus 
,so  "  [— Ischnochiton],  and  genus  Gymnoplax  Gray  [=Chiton 
.]. 

In  the  /»»,!.  ( './/,  I/nrn,  1889,  the  following  scheme  is  given  : 

Family  PIUM-HITONID^E,  genus  Schizochiton  Gray. 

Family  LOPHYOCHITONID;E.  genus  Acanthochiton  Leach. 

Family  CH^ETOCHITONID.I:,  genus  Acanthopleura  Guild. ;  genus 
Chcetopleura  Shutt.  [— Plaxiphora  -f-  Chaetopleura]. 

Family  (  in  i  «»MI»I:,  genus  Tonicia  Gray;  genus  Lepidopleurus 
rpenter,  1879  "  [— Ischuochiton  +  Trachydermon  -f-  Callochi- 
ton !] ;  genus  Chiton  L.  [=Ischnochiton  -f  Chiton  s.  8tr.~\. 

It  will  be  seen  that  the  ideas  of  Rochebrune  are  so  opposed  to 
those  of  the  Carpenter  and  the  writer  that  any  criticism  of  them 
would  be  useless.  The  same  Parisian  author  has  published  many 
diagnoses  of  Chitons  believed  to  be  new;  but  owing  to  his  failure 
to  mention  the  characters  really  diagnostic  of  genera  and  species, 
luit  little  use  can  be  made  of  his  writings.  The  majority  of  these 
forms  are  still  unfigured;  and  of  his  figured  forms  it  must  be  said 
that  IIochebruDe  has  been  signally  unfortunate  in  his  artists.  Of 
all  the  figures  of  Chitons  published  by  him  I  have  not  yet  seen  a 
correct  one  ;  most  are  so  radically  bad  that  no  dependence  whatever 
can  !><•  placed  upon  them.  The  same  is  true  of  his  figures  of  fossil 
Chitons. 

From  the  above  sketch  it  will  be  seen  that  the  chief  workers  upon 
the  classification  of  Chitons  have  been  few  in  number,  the  publica- 
tions of  BLAINVILLE,  GRAY  and  CARPENTER  successively  mark- 
ing epochs  in  the  taxonomic  history  of  the  group. 


POLTPLAOOPHOBJL 

Ci, \-iri.   M-ION  OF  Cmi< 

The  classification  given  in  this  work  is  h:H.-d   mainly  upon   < -har- 
acters  furnished    by  tlu-  articulatm-   BUrfeoei   «•»'    tin-   v:ilv«-s.      Th«: 
hard  structure  in  this  group  is  o.mparal.lr  to  tip 
ton  in  the  great  variety  of  stresses  to  whirli  it  is  suhj<-«-t.     Karl. 
valve  is  not  only  acted  upon  by  external  forces  and  its  i.ody  mus- 
cles, but  by  the  valves  before  and  behind  it,  and  by  th<-  ^m11'  • 
Hard  parts  of  great  complexity  have  thus  arisen,  offering  to  him 
who  can  decipher  their  story  clues  as  valuable  for  the  construction 
of  genealogical  lines  as  have  been  found  in  the  limb-bones  of  mam- 
mals, or  the  hinge-teeth  of  bivalve  mollusks.     The  development  of 
the  gills,  foot  and  girdle  has  been  given  due  weight,  and  for  the  first 
time,  systematic  use  has  been  made  of  the  sense  organs  of  the  shell 
(tegmentum),  and  the  system  of  sculpture  of  the  latter.     The  non- 
differentiation  of  the  dentition  throughout  the  group  has  prevented 
the  use  of  that  character  usually  so  important. 

The  Polyplacophora  known  to  us,  form  a  group  remarkably  homo- 
geneous, when  we  consider  the  vast  antiquity  of  the  stock, 
fossil  forms  are  yet  few  in  number  and  imperfectly  known ;  so  that 
all  attempts  to  trace  the  mutual  relationships  and  descent  of  modern 
genera  must  still  be  based  upon  the  morphology  of  living  forms. 
The  complex  inter-relations  of  the  various  families  and  genera,  the 
number  of  phyla,  and  especially  the  wonderful  parallel  develop- 
ments of  different  stocks,  all  render  a  linear  arrangement  of  groups 
highly  unsatisfactory.  The  accompanying  diagrams  show  the  mam 
facts  of  classification  and  descent  much  more  clearly. 

It  is  commonly  known  that  the  earlier  (Paleozoic)  Chitons  are 
without  exception,  destitute   of  plates   of  insertion,  and  belong, 
therefore,  to  the  family  Lepidopleuridce.    This  family  has  survived 
to  the  present  day,  but  the  species  are  now  few  in  number  and  of 
small  size.     The  higher  genera  of  Lepidopleuridce  possess  insertion 
plates  on  some  or  all  valves,  but  they  are  unslit;   and  it  is  to  tl 
branch  that  the  genesis  of  the  higher  Chitons  is  to  be  traced 
lowest  Ischnochitonidce  known  have  already  become  well  differenti- 
ated by  the  development  of  a  definite  system  of  slits. 

The  Ischnoid  stock  must  be  regarded  as  a  synthetic  or  uuspecia 
ized  type  of  Chitons.    In  other  words  the  common  ancestors  of 
other  families  of  the  Chitons  (except  Lepidopleuridce^  would  proba- 
bly, if  known  to  us,  be  classed  as  ItoknochitonM*.   From  this  general- 
ized Ischnoid  stock  specialization  proceeded  in  two  directions: 


XXIV  PO.LYPLACOPHORA. 

toward  greater  definiteness  in  the  positions  of  the  slits,  and  often 
nl  the  degeneration  of  the  >h» -11 ;  leading  (a)  through  Callisto- 
placiiuf  to  the  Mopnliidn,  and  (6)  through  Acanthochitidce  to  covered 
forms,  Cryptochiton,  and  to  worm-like  forms,  Cryptoplacida* ;  the 
last  having  fewer  slits  than  any  other  Chitons.  In  the  other  direc- 
tion (II)  the  slits  became  generally  more  numerous,  the  insertion- 
plates  are  roughened  for  the  stronger  adhesion  of  the  girdle,  the 
valves  increase  in  general  effectiveness  as  a  protective  armor,  and 
thrir  sense  organs  became  highly  developed.  This  phylum  (Chi- 
nlminates  in  /  vthoplewra,  Schizochiton,  Enoplo- 

chiton,  Liolophnra,  etc. ;  and  may  be  regarded  as  the  highest  group 
of  Polyj'hu'ophora. 

NOTK. — It  must  be  understood  that  in  cases  where  the  classifica- 
tion below  given  differs  from  that  in  the  descriptive  part  of  this 
work,  the  former  represents  the  mature  views  of  the  author.  Page 
n  the  text,  should  be  cancelled,  as  it  was  written  when  but  a 
small  portion  of  the  groups  there  discussed  had  been  studied.  The 
synopses  given  on  pp.  24-25,  and  148-149  also  require  correction. 

pris  of  Classification  of  the  Order  Poly placophora. 
I.  Superfamily  EOPLACOPHORA. 
Family  Lepidopleiiridce  Pilsbry. 
nus  Lepidopleurus  Risso.  p.  2. 

Section  Deshayesiella  Cpr.,  p.  16. 
Genus  Hanleya  Gray,  p.  17. 
* 

Genus  Hcrniai •thrum  Cpr.,  p.  19. 
* 

Genus  Microplax  Ad.  <fe  Ang.,  p.  21. 

1 1    Superfamily  MESOPLACOPHORA. 
Family  l*cl<n<>chttnlti<l<i  Pilsbry,  p.  253. 
Subfamily  Ischnochitoninse  Pilsbry,  p.  254. 
Genus  Tonicella  (  j.r  ,  p.  40. 
nis  Schizoplax  Dall,  p.  46. 
usCallochiton  (iray,  p.  48. 
Section  Sterochiton  Cpr.,  p.  52. 
Genus  Trachydermon  Cpr.  p.  67. 


I'OLYI'l 

Subgenus  Cyanoj.hix  I'ik,  p.  44. 

* 
Genus  Ch:<'t<>l>lrur:i  Sluittlw.,  p.  27. 

Genni  l'all<><'liit«>M  Dull,  p.  256. 
Genus  Dinoplax  Cpr.,  p.  2~>  I. 

* 

Genus  Ischnochiton  <  Jniy,  j>.  53. 

Subgenus  Stenochiton  Ad.  &  Ang.,  p.  55. 
Subgenus  Stenoplax  Cpr.,  p.  56. 

Section  Stenoradsia  Cpr.,  p.  61. 
Subgenus  Ischnoplax  Cpr.,  p.  64. 
Subgenus  Ischnochiton  s.  s.  p.  87. 

Section  Lepidozona  Pils.,  p.  125. 

Section  Radsiella  Pils.,  p.  139. 

Section  Ischnoradsia  Shuttl.,  p.  144. 
Subgenus  Heterozona  Cpr.,  p.  65. 

Subfamily  Callistoplacinse  Pilsbry,  p.  259. 

Genus  Callistochiton  Cpr.,  p.  260. 

* 

Genus  Nuttallina  Cpr.,  p.  277. 

Subgenus  Middendorffia  Cpr.,  p.  282. 
Genus  Craspedochiton  Shuttlew.,  p.  285. 

* 

Genus  Angasia  Cpr.,  p.  286. 
Genus  Callistoplax  Cpr.,  p.  288. 
Genus  Ceratozona  Dall,  p.  290. 

Family  MopaliidcB  Pilsbry,  p.  292. 

Genus  Mopalia  Gray,  p.  294. 
Genus  Placiphorella  Cpr.,  p.  305. 
Genus  Plaxiphora  Gray,  p.  311. 

Section  Guildingia  Cpr.,  p.  329. 

Section  Fremblya  H.  Ad.,  p.  330. 
Subgenus  Placophoropsis  Pilsbry,  p.  313. 

Family  Acanthochitidce  Pilsbry. 

Genus  Spongiochiton  Cpr. 
Genus  Acanthochites  Risso. 
Section  Notoplax  Ad. 


POLYPLACOPHORA. 

Section  Cryptm-onchus  Blv. 
Section  Loboplax  Pils. 
Genus  (?)  Leptophix  Cpr. 

Genus  Katharinu  Gray. 
* 

Genus  Amicula  Gray. 

* 

Genus  Cryptochiton  Midd. 

Family  Cryptoplacidce  Dall. 

Genus  Cryptoplax  Blainv. 
Genus  Choneplax  Cpr. 

III.  Superfamily  TELEOPLACOPHORA. 
Family  Chitonidce  Pilsbry. 

Subfamily  Chitoninae  Pilsbry. 
Genus  Chiton  Linn.,  p.  149. 

Section  Radsia  Gray,  p.  189. 
Section  Sclerochiton  Cpr.,  p.  188. 
* 

Genus  Eudoxochiton  Shuttlw.,  p.  192. 

Subfamily  Toniciinae  Pilsbry. 
Genus  Tonicia  Gray,  p.  194. 

Section  Fannettia  Dall,  p.  212. 
Genus  Acanthopleura  Guild.',  p.  213. 
Subgenus  Mesotomura  Pils.,  p.  218. 
Subgenus  Acanthopleura  s.  s.,  p.  219. 
Subgenus  Maugeria  Gray,  p.  226. 
Subgenus  Amphitomura  Pils.,  p.  230. 

Subfamily  Liolophurime  Pilsbry,  p.  232. 

Genus  Schizochiton  Gray,  p.  234. 

* 

Genus  Lorica  Ads.,  p.  236. 
Section  Loricella  Pils.,  p.  238. 


.. 


Genus  Enoplochiton  Gray,  p.  252. 
Genus  Onitlmdiiton  <  iray,  p.  244. 
Genus  Lioloplmra  Pilsl.ry,  p.  239. 


i-oi^  ri..\'  0FB 


xxvii 


l>h<,loy:n<t;<-  ,i;,i,tr«m  of  tfo/0m*fel  Olid  «nl.J»miHe9  of 

Polypfaoophom* 


B 

| 

J3 

O 


I 

I 


4 
1 

I 


"CallistoplacinaT 


Lepidopleuridw 

A  diagram  illustrating  the  phylogeny  of  the  genera  of  Ischnochi- 
tonina,  is  given  on  page  254 ;  another  illustrating  that  of  i          *- 
era  of  ChitoMe  is  given  below ;  and  the  descent  of  the  genera  ot 
Acanthoehitida  is  shown   under  the  head   of   that  family, 
mutual  relations  of  the  genera  included  in  CalMopla,;,,.,  >. 
clear  to  me  aud  require  much  further  investigation ;   but  the  vie 
expressed  on  pages  259,  260  may  possibly  suggest 
super-generic  groups. 


POLYPLACOPHORA. 

of  the  genera  of  Chitonidcz. 


I 
I 


d 

a 

1 

K       C 

o     o 

-r    .r 


r 


Liolophurince 


ClIITONIDJE 

ANALYTICAL  KEY  TO  GENERA  OF  POLYPLACOPHORA. 

a.   Fa/re»  /ac&mp  imertion  plates,    or  if  present  they  are  wislit 
(Lepidopleur* 

b.  Valves  entirely  exposed,  not  immersed, 
Insertion  plates  completely  absent, 

LEPIDOPLEURUS,  p.  2. 

oc.  Head  valve  having  an  insertion  plate,  grooved 
outside  hut  unslit;  valves  ii-viii  without  plates, 
-mile  xpinuloBe  HANLEYA,  p.  17. 

ccc.  Head  and  tail  valves  only  having  unslit  insertion 
plates;  girdle  thick,  sparsely  downy,  with  sut- 
ural  pores  HEMIARTHRUM,  p.  19. 


POLYPLAOOPHO1 

bb.  Valves  partly  covered,  the  exposed  portions  .-mall,  sep- 
arated MI  n, 

aa.  All  valves  possessing  insertion  plates ;  valrr\,\   \ii 

ing  slits ;  teeth  smooth  or  bid  4ig  fitly  roughened  bci>< »  »  f/" 
r  closely,  finely  pectinated;  valves  Iwkimj 
b.  Surface  of  intermediate  valves  divided  into  lat«  r:i 
central  areas  by  a  diagonal  (often  in.listinct),  extend- 
ing from  beak  to  outer  front  angle  of  tegraentum  ;  or  if 
this  is  not  clearly  the  case,  the  posterior  valve  has  un 
even,  crescentic  series  of  well  developed  teeth  ;    all 
valves  having  slits. 

c.  Posterior  valve  having  a  crescentic  series  of  well 
developed  teeth  (Ischnoch \\m>  > 

d.  Anterior  and  side  slits  not  corresponding  in 
position  to  external  ribs  (Ischnochitonina.) 
e.  Valves  porous  at  the  eaves,   appar- 
ently  smooth   outside  or  nearly  so ; 
teeth   sharp,   smooth;    girdle  naked, 
sparsely  hairy  or  densely  covered  with 
elongated  corneous  bodies,  the  visible 
ends  of  which  appear  like  diamond- 
shaped  scales  (Tonicelloid  group). 
f.  Sutural     plates    not    connected 
across  the  sinus ;  girdle  naked  ; 
side-slits  single ;  gills  shorter  than 
the  foot. 

g.  Median  valves  having  a  me- 
dian slit  filled  with  carti- 
lage,     SCHIZOPLAX,  p.  46. 
gg.  Median  valves  normally  <  al- 
cified,      TONICELLA,  p.  40. 
ff.  Sutural  plates  connected  across 
the  sinus,  or  side-slits  several,  or 
both ;  girdle  either  sparsely  hairy, 
naked,  or  with  compact  diamond- 
patterned  covering;  gills  as  long 
as  the  foot,  CALLOCHITON,  p.  48. 
(This  includes  the  typical  forms 
of  Trachyradsia,  p.  83.) 
jgjf.  Girdle  with  chaffy  scales  or  pap- 


XXX  POLYPLACOPHORA. 


illose ;  gill-row  short  or  long, 

TRACHYDERMON,  p.  67- 
ee.  Valves  solid  at  eaves,  generally  with 
beaded  sculpture ;  teeth  sharp,  often 
rugose  outside;  girdle  leathery  with 
few  or  many  hairs  or  spiculse,  never 
scaly ;  gills  as  long  as  the  foot  (Chat;*  - 
pleuroid  group). 

/.  Sinus  squared,  the  sutural  plates 
not  connected  across  it;  girdle 
hairy  or  naked. 

g.  Mucro  in  front  of  the  mid- 
dle,  CH^ETOPLUERA,  p.  27, 
[and  appen'H.r. 

gg.  Mucro   decidedly  posterior, 

PALLOCHITON,  p.  256. 

ff.  Sutural  plates  connected   across 

the  sinus ;   girdle  thick,  bearing 

minute  clumps  of  short  spicules, 

DINOPLAX,  p.  254. 

eee.  Valves  solid  at  eaves ;  girdle  densely 
covered  with  imbricating  scales,  rare- 
ly elongated  like  fluted  pillars  (Isch- 
noid  group)  ISCHNOCHITON. 

/.  Shell  much  elongated,  narrow 
(gills  short  at  both  ends ;  foot  no- 
tably dilated  and  produced  in 
front,  at  least  in  some  of  these 
sections). 

g.  Girdle  scales  uniform  ;   mu- 
cro  near  the  middle 

h.  Valves  longer  than 
wide,  roundly  arched, 
with  several  side  slits; 
animal  Julus-like, 

Stenochiton  p.  55. 
hh.  Less  elongated;  Amer- 
ican forms 

Stenoplax,  p.  56. 
gg.  Girdle  scales  very  unequal ; 


POLYFLAOOFHOfl 

raucro  el 

/ 
ff.  Shell  not  ^n  ally  .-IniiL 

g.  ( iinllc  clothed    with    large 
ami      small       iiit'Tiningled 
scales,       Heterozo 
gg.  Girdle  scales  regular,  uni- 
form. 

h.  1  slit  on  each  side  of 
median  valves 
i.  Girdle  scales  flat, 
lachnochiton,  p.  86. 
ii.  Girdle  scales  very 
convex, 

Lepidozowi,  \>.  1  '_'•"». 
hh.  2  or  more  slits    on 
each  side, 

i.  Girdle  scales  flat, 
Eadsiella,  p.  139. 
ii.  Girdle  scales  con- 
vex, 

Ischnoradsia,  p.  144. 

dd.  Anterior   and   side  slits  corresponding  in 
position  with  external  ribs  (Callistoplacinae). 
e.  Surface  of  valves  having  strong  radial 
ribs  ;   girdle  densely  clothed  with  im- 
bricating scales, 

CALLISTOCHITON,  p.  260. 
ee.  Surface  of  valves  granulated  or  peb- 
bly ;  girdle   not   densely   imbricated 
with  scales. 

/.  Anterior  valve  with  more  than 
7  slits ;  sinus  very  spongy ;  mu- 
cro  posterior, 

NUTTAI.I.INA.  J>.  -77. 

ff.  Anterior  valve  with  .">  slits ;  mu- 

cro  subcentral,  not  posterior, 

g.  No  sutural  pore  tufts. 

CRASPEDOCHITON,  p.  285. 

gg.  Sutural  pore  tufts  present, 

A  NC.ASIA,  p.  286. 


\X.\ii  POLYPLACOPHORA. 

e>  f.  Surface  of  valves  wrinkled  or  ribbed  ; 
girdle  naked  except  for  hairs  or  cor- 
neous spines. 

/.  Valves  having  very  strong  radial 
ribs;  girdle  naked,  with  sutural 
tufts,        CALLISTOPLAX,  p.  288. 
jj.  Valves  not  very  strongly  sculp- 
tured ;  girdle  tough,  with  corne- 
ous curved  spine-like  processes, 
CERATOZONA,  p.  290. 

Posterior  valve  having  a  sinus  behind,  with  one  slit 
or  none  on  each  side ;  girdle  hairy  or  nude,  never 
scaly  (Mopaliida').     See  key  to  genera  on  page  293. 
66.  Surface  of  intermediate  valves  divided  into  a  narrow 
dorsal  area,  and  latero-pleural  areas,  the  latter  formed 
by  the  union  of  the  lateral  and  the  pleural  (or  sides  of 
the  central)  areas  ;   valves  more  or  less  covered  by  the 
naked,  spiculose  or  hairy  (never  scaly)  girdle ;  gills  gen- 
erally short  (Acanthochitoid  phylum). 
c.  Posterior  valve  either  having  well  developed  slits, 
or  a  posterior  sinus,  or  both ;   not  funnel-shaped, 
anterior  valve  with  5  or  more  slits  (Acanthochiti- 
dce,  see  next  volume  for  species). 

d.  Valves  not  completely  covered  by  the  girdle, 
the  first  7  having  their  apices  posterior  and 
marginal. 

e.  Anterior   valve   having    5   regularly 
placed  slits;  exposed  portion  of  each 
median  valve  much  longer  than  wide. 
/.  Girdle  provided  with  pores  bear- 
ing tufts  of  bristles  ;    posterior 
teeth  wanting  or  irregular 

ACANTHOCHITKS. 

ff.  Girdle   naked ;    posterior   valve 
with  6  slits,  the  teeth  even,  spread- 
ing LEPTOPLAX. 
jfjfjf.  Girdle  spongy,  produced  forward 
as  in  Placiphorella 

SPONGIOCHITON. 


POLYPLACOni«H:\. 

ee.  Anterior  \ 

larly  spaced,  mon-  than  •"> ;    j.o.st«-i 
valve  with  :i  median  angular  t 
its  edge  with  several  uni-<|ual  notched 
or  slits;  exposed  part  of  valves  flask- 
shaped  I\  \iiii 
eee.  Anterior  valve  having  6-8   un< 
slits;  posterior   valve   2   slit-  ai, 
median  wave;    expoM.I   part  of  each 
valve  far  shorter  than  the  ridge  of  the 
valve,  heart-shaped  A.MICULA. 
dd.  Valves  completely  covered  by  the  girdle, 

their  apices  not  marginal,    CRYIT<M  m 
b.  Median  valves  partly  lacking  side  slit-  ;  tail  valve  with 
2  or  no  slits 

cc.  Posterior  valves  without  distinct  slits,  and  huvini: 
no  posterior  sinus  ;  more  or  less  hollowed  out  and 
funnel-shaped  ;  anterior  valve  with  3-5  slits  ;  body 
rather  vermiform  ;  gills  short,  posterior  (Cryptopla- 
cidce  ;  see  next  volume  for  species). 

d.  Valves  small,  narrow  and  sagittate,  gener- 
ally partly  disjointed ;  not  covering  the 
body  to  any  considerable  extent 

CRYPTOPLAX. 

dd.  Valves  transverse/all  strongly  imbricating ; 
covering  a  considerable  portion  of  the  upper 
'surface  CHONEPIAX. 

aaa.  All  valves,  or  valves  i-vii,  possessing  insertion  plates  cut 

teeth  by  slits ;  the  teeth  sharply  sculptured  or  "pectinated  "  out- 
side by  fine  vertical  grooves  (Chitonidce). 
b.  Valves  lacking  eyes  (Chitoninoe). 

c.  Girdle  scaly  CHITON,  p.  141». 

cc.  Girdle  leathery,  with  short  bristles 

EUDOXOCHITON,  p.  192. 

bb.  Valves  having  eyes ;  posterior  valve  not  deeply  simiM-d 
behind,  its  insertion  plate  developed  (Tonic! ; 

c.  Girdle  leathery,  nude  or  nearly  so,ToNiciA.  j>.  L94, 
cc.  Girdle  covered  with  calcareous  spines  or  spinelets, 

ACANTHOPLEURA,  p.  213. 

bbb.  Valves   having    eyes    (rarely   subobsolete) ;    posterior 


XXXIV  POLYPLACOPHOKA. 

valve  either  having  a  deep  sinus  behind,  or  lacking  the 
insertion  plate  altogether  (Liolophurince). 

c.  Median  valves  having  eyes  developed  only  on  the 
diagonal  ribs.  Sinus  notably  narrow  and  small. 
Insertion  plates  of  tail  valve  a  low,  rounded, 
rugose  ridge  more  or  less  notched,  slit  or  waved 
upward  in  the  middle  behind,  or  sharp,  long  and 
pectinated. 

.ves  developed  on  radiating  ribs  of  all 
valves;  the  ribs  of  head  valve  correspond- 
ing to  internal  slits ;  girdle  having  minute 
spines ;  shell  elongated,  posterior  valve  and 
girdle  slit  behind  SCHIZOCHITON,  p.  234. 
'/</.  No  eyes  on  head  valve,  its  riblets  not  corre- 
sponding to  slits ;  girdle  densely  scaly 

LORICA,  p.  236. 

cc.  Eyes  developed  upon  the  lateral  areas.  Sinus 
wide  and  large.  Insertion  plate  of  the  tail  valve 
reduced  to  a  smooth  ledge  or  ridge,  having  no 
posterior  sinus  or  wave. 

d.  Valves  polished  or  eroded,  dark  brown  out- 
side and  within,  having  excessively  minute 
eyes  scattered  over  lateral  areas  and  head 
valve  (when  not  eroded) ;  interior  very 
densely,  minutely  and  peculiarly  grooved 
and  punctured.  Girdle  fleshy,  bearing  sep- 
arated rude  scales,  ENOPLOCHITON,  p.  252. 
dd.  Valves  polished,  colored  outside,  porcella- 
nous  and  smooth  within,  having  the  eyes 
disposed  in  radial  bands  on  each  lateral 
area  and  the  head  valve.  Girdle  leathery, 
microscopically  velvety, 

ONITHOCHITON,  p.  244. 

ddd.  Valves  lusterless,  granulated,  having  minute 
eyes  scattered  over  the  lateral  areas,  sides 
of  the  central  areas,  and  head  valve.  Gir- 
dle densely  covered  with  stout  calcareous 
spines  LIOLOPHURA,  p.  239. 


LEPIDOPLEURID2  . 

Lap  totVfca  CARPENTER. — Lept<n-hitnni<lti  IJ.M.I.,  '  Dlake1 
p. -ill.  L889.— Genui  7/Wor/,;/o//  FISCHER,  Manuel  «!«•  Com-hyl.  p. 

*77,  1  - 

ChitODS  in  which  the  head  and  tail  valves  arc  similarly  articu- 
lated, and  having  the  insertion  plates  either  obsolete,  or  if  pn- 

without  slits.  Girdle  finely  acaly  or  bristly ;  gills  short,  posterior. 
This  family  is  readily  known  by  the  entire  absence  of  insertion- 
plates,  or  the  Min pie,  nimlit  character  of  them  when  present.  The 
living  species  are  few  in  number,  and  mainly  either  northern  in  dis- 
tribution, or  living  at  considerable  depths.  All  of  the  Palaeozoic 
Chitons  yet  known  belong  to  this  family,  and  this  fact,  together  with 
the  weak,  imperfect  articulation  of  the  valves,  causes  us  to  regard 
the  Leptoids  as  the  most  primitive  of  the  existing  groups. 

Synopsis  of  Genera. 

A.      Valves  entirely  exposed,  r>ot  concealed  by  the  girdle. 
B.     Girdle  without  pores. 

Genus  I.  LEPIDOPLEURUS  Kisso,  1826. 

Insertion  plates  absent.  Girdle  with  minute,  gravelly,  smooth  or 
striated  scales,  usually  with  a  marginal  fringe  of  longer  scales. 
Type,  L.  cajetanus  Poli. 

Section  Deshayesiella  Carpenter,  1878.  Girdle  having  delicate 
spines  and  chaffy  scales.  Valves  curved  and  beaked ;  sutural 
plates  and  sinus  as  in  Leptochiton.  Type,  L.  curvatus  Cpr. 

Genus  II.   HANLEYA  Gray,  1857. 

Front  valve  having  an  insertion  plate  which  is  grooved  outside 
but  without  slits.  Intermediate  and  posterior  valves  without  inser- 
tion plates.  Girdle  finely  spiculose,  without  pores.  Type,  JL  huii- 
leiji  Bean. 

BB.      Girdle  with  pores  at  the  sutures. 

( ienus  III.  HEMIARTHRUM  Carpenter,  1876. 

Head  and  tail  valves  having  smooth,  unslit  insertion  plates,  the 
intermediate   valves   without   insertion   plates.      Sinus   broad    and 
1  (1) 


2  M  i'iiM>i-i.i:rRU8. 

spongy.    Girdle  downy,  having  small,  tufted  pores.     Type,  H.  set- 
ulosiun  ( 'j.r. 

A  A.     Valves  partly  covered,  the  expose<  small  and  sepa- 

rated. 

\\\(  K<  H'LA  X  Adams  &  Angas,  1804. 

Insertion  plates  smooth  and  thin,  well  developed  in  all  the  valves, 
ml  plates  and  sinus  obsolete.     Girdle  thin,  most  minutely  gran- 
ular, not  jM»riferous.    Type,  M.  proyiAd.  &  Ang. 


Gem.-  I.  LEPIDOPLEURUS  Riaso,  1826. 

pleurus  Risso,  Hist.  Nat.  1'Kur.  M.'rid.,  iv,  p.  267,  1826, 

in  :  t  species  /,.  c,ij*t>tnns  Poll). — SARS.,  Moll.  Reg.  Arct. 

.,    1*7*,  }».  1  in.     Nut  L'-ftidoplenrus  of  H.  &  A.  Adams,  Car- 

:  'all.  ft  •i/.—Lrptorhiton  GRAY,  Proc.  Zool.  Soc.  Lond.  1847, 

j».  1  H  I1..  M..  p.  182,  1857.— CARPKM  I:K,  J/&  p.  1,— 

-         ; .  Mus.  1878,  p.  3\±.—Leptochiton,  in  part,  of 

H.    A     A.    A  i. A  MS,   Gen.  Rec.  Moll,  i,  p.  473,    and   of  CHUM  , 

Manuel,  i,  p.  381. 

In  /  itioii   plates  are  completely  absent;  the 

girdle  is  narrow,  with  minute  striated  or  smooth  scales,  and  some 
_rer  scales  at  the  edge. 
The  present  genus  has  hitherto  been  known  as  Leptochiton,  but 

:vji-i-tioM   of   that   name  seems  to  be  inevitable  as  will  be  seen 

DO  the  following: 

//    •     '.    of  the   name  Lfj'irl»i>/>-urii.<.     The   first    publication   of 

Lepi-  l  in  Kisso's  Histoire  Naturelle  des  principales  pro- 

!•••  Mi'ridiojiale,  vol.  iv,  p.  267,  182G,  where  ii    is 

•«NJ  as  of  Leach's  ww.  It  is  character! zed  as  having  the  triangular 
lateral  areas  elevated  and  the  girdle  covered  with  small  scales,  and 
in  it  are  includ<-d  .711)  L.  cayetanns  Poli,  (712)  L.  coral/inn*  n.  sp. 
and  (713)  L.  sul&itus  n.  sp.  Of  these,  the  first  species  belongs  to 
the  v  '•  .  Mib.-e.juently  named  I,e]ttocliiton,  and  the 

two  latter  belong  to  the  genus  Chiton  as  restricted  to  Lin  nuns' 
type.  It  is  there!'"!.'  evid.-nt  that  if  u>.-d  at  all.  the  name  Lepido- 
plcn  ;.rojM-rly  be  ii>,-d  foi  |  ,,,,lv.  It  is  greatly  to 

be  regretted  that  it  was  not  so  used  by  <  iray,  as  much  subsequent 
confusion  would  have  been  avoided.  The  rej.ublication  of  the 


i.i  PIDOPLE1  i  '{ 

•Trims  in  (  Iray's    edition    of    L.-arh'  I/,-        -  jn 

'.  need  not  he  omsidrivd  here  ai  ii   \\-.\-  no  hcarim:  upon  mmi.-n- 
rlatun>.       In    1868,    Me«r»,    II.    ami    A.    Adams,    in    tli«-    <, 
Recent    Mn//nwt,    adopted    llisso's    nanir    for   a    I:ir_r(i  li-t  0 
mainly   of    Ttehnochitoni,   l>ut    inrludinir  al 

Lcpfnchitttn,  etc.,  among  them  L.  m/v/. /////.-•  I'oli.    • 

priitrr  in  his  later  writing  used  LepidopUufW  !••  rover  tliat  '_rroiip 
of  Isrlmorhitons  liavini:  the  girdle  clothed  with  large,  .-niooth  nm- 
\ •«  A  <caK-s,  like  those  of  the  typical  Chitons.  Nothing  can  !•«•  -aid 
in  tiivor  of  this  use  of  the  name,  for  Carpenter  expressly  states  that 
the  species  cited  by  Risso  are  excluded  from  the  group  as  re-habili- 
tated! It  is,  therefore,  obvious  that  Lepidopleurus  Cpr.  is  a  totally 
distinct  group  from  Lepidopleurus  Risso.  No  argument  is  ne<-di-d 
to  show  the  untenability  of  Carpenter's  position.  In  1880,  Cam-, 
in  his  Prodromtu  Faunce  Mediterranean,  has  used  Lepidopleurus  as  a 
subgenus  under  Chiton  (which  he  places  in  the  Ischnoidea !  j,  and 
has  included  in  it  species  of  Trachydermon  and  Ischnochiton,  as 
well  as  Leptochiton  cajetanus.  In  1878  G.  O.  Sars  correctly 
restricted  Lepidopleurus  to  the  genuine  Leptochitons. 


L.  CANCELLATUS  Sowerby.     PL  3,  figs.  54,  55,  56,  57,  58. 

Shell  small,  elongated,  much  elevated,  regularly  arched,  not 
anirled.  Orange-ashen  or  .whitish. 

Anterior  valve  radiately,  evenly,  very  finely,  granose-1  irate. 

Central  areas  of  the  intermediate  valves  having  distinct  longitu- 
dinal, fine,  close  granulous  line,  the  granules  being  sometimes 
arranged  in  transverse  lines  also,  giving  a  latticed  appearance  ;  lat- 
eral areas  distinct,  decidedly  raised,  convex,  having  radiating  but 
rather  irregular  rows  of  granules. 

Posterior  valve  with  central  elevated  apex  ;  posterior  slope  con- 
cave. ' 

Interior  white,  the  sutural  plates  small,  triangular:  juiral  sinus 
very  broad. 

Girdle  narrow,  densely  beset  with  delicate,  scarcely  imbricating 
or  striated,  scales  (figs.  55,  57). 

Length  5],  breadth  2 2  mill.;  divergence  80°. 

Northern  Atlantic  and  Arctic  Seas. — Britain  ;  Norwegian  Coast 
in  ">0-100  fms. ;  Lofoten  Is.  300  fins. ;  Greenland:  South  to  Gulf 
of  Lyons,  Vigo,  Spain  (and  Dalmatia  /).  Northern  I'lirific. — .-1  tnskn, 
at  Unalashka,  Shumagins,  Port  Etches  and  Sit/:n  II<;r/i<>,\  o'-loo  t'ms. 


4  LEPIDOPLE1 

ii  m*.}.  Conch.  111.  f.    1()4- 

3&    HAM 

Brit,  M-'ll.  ii.  I>.  -Jl(>.  :  Brit.  <  «nch.   iii, 

p.    -J17:    v.    p.  l'.    I. —  Lr/.i'lnjJtuirns    r'tnrellntn*    BARS, 

Moll.  ..   p.    IN.  t.  7.  f.  6;  t.i,f.&.—Lq)tochiton 

i/>,  p.  :;.-  -  Du.i..  Proc.  I".  6.  Nat.  Mu,.  187* 

Linn..//'/'   Hanlcy. —  Chiton  as  ellus 
MIDI.., not  .if  Lowe.— (  An  r.,  n..t  Payr. — /  Ch.  isliimliru* 

Tli  without  careful  inspection  will  usually  be  confounded 

wiih   small    specimen-   of    Tr'irliinlcnmiH    iiUnis,  but  a  --lance  at  the 
sculpture  i-  -utlicient  to  separate  it.      From  several  other  species  of 

ailily  distinguished,  and  a  magnifier  is  indis- 

•ahlr.     The  ditlerential  characters  are  as  follows: 
The  pu.-tules  which  constitute  most  of  the  sculpture  are  arranged 
like  overlapping  coins  or  a  solid-linked  chain  in  lines  which   in    the 
1    area   an-    nearly    parallel    with   the    longitudinal  axis  of  the 
animal.      The  lateral  area-  are  distinct,  and  the  pustules  upon  them 
in  rather  indistinct  lines  radiating  toward   the   lateral 
of  the  valves,  at  nearly  right  angles  to  the  lines  on  the  dorsal 
ilpture  on  the  mucro  is  more  delicate  than    elsewhere. 
The  apex    of    the   po>terior  valve  is  not  sunken  and  is  not  so  sharp 
-i>ecies  compared  with  it  here  ;  the  girdle  is  scaly,  with 
-mall,  spino^e,  transparent  scales  near  the  margin.    There 
live   Lrill    plume-   on    each    side,    prominent    and    near   the  vent. 
pear  to  be  two  fenestra    on   each   side.      The  lateral   areas 
.(her  portions   of  the    valves   are   nearly    always   colored   with 
blacki-h    or    frrniL'inoiis   patches,    but  these,  as  with   Tr<i('lii/(lcnnnn 
n/bn#  >eem  to  be  really  c<.mpo>ed  of  extraneous  matter.      In  L.  fuli- 
Ad.  A:   live.,  the  pustules  are  much  smaller,  and  while  hav- 
ing a  Lfeneral  longitudinal  arrangement  on  the  dorsum,  do  not  form 
llariy  defined  TOWS  Or  chains.      The  areas   are    not    raised    above 
the    dor-uni.      The   shell    is    much    larger  and  more  elevated,  with  a 
:iken    and    «|iiite    sharp    posterior    mucro.     Tin-    other 
nine  ii"i  raided  but  about  them  the  sculpture  is  more  regu- 

larly aliened  than   eUewhere.      1    have    compared    the    valve-    of    a 
typical  >|M-< -iinen  from   Korea,  collected  by   Belcher.       I  figure 

of  the  sculpture  i-  very  bad.  as  are  nio-t  of  his  details.      L.  alveolus 
di-tinct  though  it  has  been    confounded    with 

thi-.      It-    sculpti;!  and  rather  ni..iv  Sparse, 


LEPIDOPLEU1  ."i 

isolated    puMiilr-,    alxoliitcly    irn-Lrular    in    di-l  ril.ul  i<  •: 
same    .-!/«•    on    the    mucro    ;in<l    eUr\\h« -re.      N«.\\l 
Iille>.       The  aicll   of   tin-  back    is   |  >eci  1 1  ia  ll  y    P>und.     the     lat-  : 
not    rai^-d    ami    barely    di>tiniMii>hai)le.      The    girdle  seem 
I   have  compared  typical  examples. 

L.  ooncmnttt  Gould,  from  the  types,  ifl  of  i  diilen-nt  color,  and 
has  a  much  M router  and  different  sculpture  like  line-  of  i 

L.  inft'nir.rii.'S  (  'arpenter  and  var.  rui/nln.*  (  'pr.,  are  more  like 
cinnii*,  hut  di-tin^-mslied  from  either  by  the  peculiar  ^irdl- 
with  sul>e<|iial  scales. 

L.  nexn*  ('arpenter  more  nearly  resembles  c.ancellatns  but  the 
sculpture  is  of  separate,  not  lapping,  rounded  rhomboidal  pu>n 
the  mucrones  are  much  more  pronounced,  and  the  white  ground  i- 
prettily  marbled  with  black  and  gray  inherent  coloration.  The 
name  cancellattu  is  a  misnomer,  since  it  is  only  in  certain  lights  that 
any  trace  of  reticulation  can  be  observed  faintly.  The  young  are 
flatter  than  the  adults.  It  bears  no  resemblance  to  L.  asellus,  with 
which  Middendorff  united  it,  probably  without  a  comparison. 

L.  arcticus  of  Sars  seems  to  be  a  finely  grown  variety  of  this  spe- 
cies, if  one  may  judge  from  the  figures;  at  least,  no  differential 
characters  are  given  which  seem  to  be  of  a  permanent  character, 
and  not  subject  to  variation  within  the  limits  of  a  species. 

The  gills  occupy  a  space  corresponding  to  the  posterior  quarter 
of  the  foot ;  there  are  about  eight  or  ten  on  each  side.  The 
mantle  edge  is  plain  and  thick.  The  veil  is  plain.  The  muzzle  is 
rounded,  with  a  little  papilla  at  the  posterior  corner  on  each  side 
(Dall.) 

L.  ARCTICUS  Sars.     PI.  3,  figs.  59-63. 

Shell  subdepressed,  dorsal  keel  obsolete,  lateral  areas  little  con- 
spicuous.      Posterior    valve  smaller  than  the  anterior,   subrhom- 
boidal,  roundly  produced  in  front.     Median  plates  throe  tim- 
long  as  broad,  the  front  margin  truncate  in  the  middle.     Surface  of 
the  valves  nearly  smooth,  indistinctly  granulose.     (Sars.) 

Length  12  mill. 

Spitzbergen,  Greenland,  Vadso  and  Finmark,  20-10*  • 

Lepidopleurus  arcticus  SARS,  Moll.  Reg.  Arct.  Norv.  p.  11-,  t.  7, 
f.  7.—  Chiton  aretiew  JEFFREYS,  P.  Z.  8.  1882,  p.  668. 

Dall,  judging  from  the  description  and  figures,  considered   tl 
form   of   L.  cancellatus.      Jeffreys,   who   found   the   -  D    the 


b  LEPIDOPLEUBUS, 

'  Lightning'  dred-ini:-,  -ays  that  it  differs  from  the  white  variety  «if 
euf  [--ascllus]  in  its  comparatively  greater  length  and  more 

raised  or  arched  form,  in  the  less  distinct  or  regular  catenation  of 
granules  which  OOVer  the  surface,  and  in  the  prominence  of  the 

lateral  areas. 

I..  \i.\  r.M.rsSars.     PI.  2,  figs.  23-' H . 

Shell  quite  convex,  hack  equally  arched,  without  trace  of  a  keel 

or  defined  lateral  areas :  valve-  rather  elongate,  the  posterior  larger 

than   the  anterior  valve,  half-round,  truncated  by  a  straight  line  in 

t'n.nt:    median    valves  subequal,   their  posterior  margins  straight, 

rior  margins  lightly  emarginate  in  the  middle.     Entire  surface 

1  witli  minute  ovate  tubercles,  regularly  disposed.     (Sars.) 

Length  16  mill. 

North  Atl'tntir  at  Bergen,  Lofoten,  Finmark,  150-300  fms. ;    Bay 

of  Jiiwitt,  ]  i_>n-6fi4  fms. ;    Gulf  of  St.  Lawrence  betiveen  Cape  Rosier 

\   1C.  /,„/„/  of  Anticostild.,  220  fms.;    St.   George's  Bank, 

',e,  150finfl, 

•dveolm  (SARS  ms.)  LOVEN,  Ind.  Moll.  Lit.  Scand.  p.  L'7, 
159,  1846. — I  ii  PREYS,  P.  Z.  S.  1882,  p.  G68.—Lepidopleurus  alve- 
olus G.  O.  SAI:>,  Moll.  Reg.  Arct.  Norv.  p.  110,  t.  7,  f.  3  ;  t.  i,  p.  7, 
ISlS.—Leptochitn,,  alveolus  DALL,  Proc.  U.  S.  Nat.  Mus.  1878,  p. 
:I17.—  II  A  i 'DON,  Challenger  Rep.  vol.  xv,  p.  12. 

L.  i-i.i:«;i:  \vvrrs  Dall.      Vn  figured. 

Shell  elongated,  moderately  elevated,  regularly  arcuate,  without 
jugurn.  Pale  wax.-n,  sometimes  white.  Valves  wide,  without 
•  .s.  Front  and  back  valves  more  or  less  concave;  posterior 
valve  without  elevated  apex.  Sculpture  as  in  L.  cancellatus,  but 
th«-  -ninnies  larirer,  lateral  areas  less  defined.  Sutural  plates  elon- 
gated. <  iirdh-  wide,  densely  beset  with  delicate  scales.  (Dull.') 

1    Qgth  !_'.  breadth  6i  mill. 

Near  Dominica,  West  Indies,  in  138  fms. 

Lepfoekiiok  J,' r<jr<ntat,i$  I)\F.L,  'Blake'  l\ep.  p.  414,  1889. 

This  fine  species  is  nearest  the  Atlantic  L.  c<mre/l<itu*  Sc.werby, 
:"i«l  '  Ad.  <fe  Reeve.     It  differs  from  both 

in  its  concave  or  excavated,  instead  of  convex,  terminal  valves,  in 
the  absence  or  obsolete  condition  of  the  posterior  mucro,  in  its 
much  larger  and  inure  regular  granules,  and  in  the  subdeprcsscd 
appearance  also  of  the  {.art  of  the  median  valves  near  the  girdle 
on  each  side.  It  is  larger  than  <,,„,,  //,,/„.<  all<i  smaller  than  ;'////- 


i.i  ri  ix  >ri  i  i  i 

,  and  without  the  dinu'V  hlaekish  pai  nt  in-  of  either.      / 
crl/ntu.<    is    narrower,  higher,  and  \\itli  a  -harper  medi:m  aiiL'Ir.      |M 
L.  fnli  t/iiiiifn.*  the  middle  valve-  are  ihortei  from  front  t<.  liaek,  tli.' 
sutural  lamina-  .-mailer    and    much    more    tri;iii'_:ular.      Th- 
siirii    of    a    niucro    on    these  valves,  hut  in   /,.  y,/-/-///-//,,,////.*  t  in  TO  \»  a 
beginning  of  one,  <|iiitc  perceptible.     The  latter  i.-  a    pn.pi.rt  ionallv 
wider  and. Hatter  species,  with  a  stronger  and  more  prominent  girdle 
densely   set    with  elongated  silvery  scales  like  short  <titf'_rr;i\   1 
these   form  a  pretty  fringe  at  the  periphery.     The  sculpture  foil 
tlui  pattern   of    I,,   canc.dltitn*,  hut,  the  lateral  areas  are  less  r|<arl  \ 
defined,  the  granules  are  more  clearly  cut,  more  regularly  arranged 
and  larger  than  in  any  of  the  species  hitherto  known.     There  are 
twelve  gills  on  each  side,  reaching  forward  to  about  the  middle  of 
the  sixth  valve.     (Dall.} 

L.  BELKNAPI  Dall.    PL  1,  figs.  18-22. 

Shell  elongated,  much  elevated,  dorsally  angled;  whitish,  more 
or  less  tinged  with  ashen  or  black.  Valves  elevated,  with  distinct 
apices  ;  mucro  central,  conspicuous.  Sculpture  as  in  L.  alveolus, 
but  the  granules  of  the  dorsal  areas  sparse,  and  disposed  in  quin- 
cunx. Posterior  valve  concave  below  the  apex,  sinuated  behind. 
Girdle  narrow,  having  delicate  spicules  toward  the  margin.  {Dall.) 

Length  10,  breadth  3  mill.;  divergence  90°. 

North  Pacific  Ocean  in  lat.  53°  08'  N.t  Ion.  17°  19'  IF.,  at  a  depth 
of  1006  fms.  ;  off  Cape  Bolinas,  Luzon,  Philippines,  1050  fins. 

LeptochitonbelknapiDAL^PTOc.  U.  S.  Nat.  Mus.  1878,  p.  1, 
Jan.,  1878 ;  I.  e.  p.  317. — HADDON,  Challenger  Kep.  xv,  p.  ID,  t.  1, 
f.  2  ;  t.  2,  f.  2. 

This  specimen  much  resembles  L.  alveolus,  to  which   I  at  first 
referred  it.     A  careful  microscopical  examination,  however,  shows 
differences  which  I  am  disposed  to   consider  specific;  but  I  have 
but  one  specimen,   and  others  might  show  modifications  in   the^e 
particulars.     The  differential  characters  are  as  follows:    In  afr- 
the  pustules  are  distributed  evenly,  closely  and  in  no  pattern  what- 
ever, all  over  the  surface.      In  belknapi,  they  are   more    widely 
separated  and   arranged  in   quincunx   on   the  dorsuin,   the  s\ 
>eeming  to  radiate  from  the  median  dorsal  line.     In  a/tW//.<  the  lat- 
eral areas  are  barely  perceptible.     In  belknapi  they  are  raised,  con- 
centrically rugose,  and  the  pattern  of  the  pustular   arraiiL.rcm»! 
different  and  more  irregular  than  that  on  the  dorsum.     In  belktiapi 


LEPIDOPLEUR1  3. 


thin,  narrow,  and  sparely  96l  with  small  pel- 
lucid ipiculea  Dear  the  mar-in.      Ti  ior    mucro   or   up. 

lllr  [Tile,   in  ^flop^  is  prominent,  overhangs  a  shallow 

J  ami  fV..,n  its  point  there  diyerp-  anteriorly  t\mr  depr 

the  anterior  lateral  an-l.->   of    tin-    plate,    the 

inn.  :idi-tant  from  each  ot her  and  the  outer  Iiu,->.      I'.etween 

the    plat.-    ^    >welled,    formini:    three    rounded    ridges, 

ruard  like  th.-  leaflet-  of  a  trefoil  <»r  clover,     Nothing 

•iiblm-  thi>  ha>  been  •»!>«•  rvcd  on  any  of  the  other  species  which 

have  oome  under  my    notice.      The  >,,ft    parts    in    spirits   appeal-   to 

Other  Bpeciefl  compared  with  it.      It  is  evidently  adult 

Tl''  Bent  the  form  dredged  l.y  the  'Challen-er1  ,,tr 

mt  Thilippines.       Had.lon  describes  these  specimens  a<  fullcws: 
S|l(l11-      l>nttl.-.  cloaelj  Covered  with  larire,  round,   .smooth    tuber- 
i  an  angle   of  about   110°.     Sutural   lamina- 
all. 

r  valve.— With  a  few  irregular  lines  of  «rrowth,  thickly 

•A  ilh  irregularly  disposed  tubercles. 

'li:ltt>  v^'  ntral  areas:    with    a    shallow   depression 

:  -h  Bide  "f  the  median  rid^.,  which  givea  the   latter   a   pinched 

:  his  depn-sion  is  mo>t  apparent  at    the   hinder   border 

The    tubercles    have  a    -eneral    arrangement    in 

ol.li.ju,'  liiu-s  ra.liatin-  forwards  from  the  keel  and  at  the  same  time 

i"  li'  Btric  to  the  umbo,  but  these  two  series  of  lines  are  not 

'.  and  the  tubercles  often  appear  to  be  irregularly  dis- 

!'    short    eoncentric    rows    usually    demarcate    the 

1  the  lateral  areas.     Lateral  areas:  scarcely ap- 

ndicatin.i:  a   line   of  -rowth  occurs  at  a  short  dis- 
Mle;    tubercles  irregularly  disposed,  with  a  ten- 
'..  however,  to  concentric  lines. 

With  a  small   subeentral    umbo,   behind    which 
Interior    area:      the     lateral     lon-itudi- 

""I  ''  tejugum  to  be  slightly    prominent    and    thus 

give^    the  anterior  inewhat  trilobed  appearance;   the  tuber- 

Bnded   keel.     Posterior  area;  with  ooncen- 

i  and  el-.-elv  >rt  tuber, 

.  thickly  covered  with  delicate  small  oval  scales; 
:ini1   more  pointed  scales  occur  along  the  border 

and  in  th-  !vr> 


8 


.-    (  irayish-whitr. 
Si/.,-.      Len-th  about    rjmm.;   hivadlh  ~>  mm.  ;    hriirhi 


inin. 


s. Fornmi-  a  short   po-terior  n»w,  ^i\  <.r  seven  in  number. 

This  species  is  considerably  lar-er  and  OOartOT  than  tin-  |>i 

(L.  benthut').    The  tubercles  are  twice  the  size  and  <•!•  ther, 

The  shell  IB  also  Comparatively  >harply  keel.-d,  instead  of  having  a 
uvntlv  rounded  appearance. 

L.  BEVTHU6  Haddon.      IM.  1,  ligs.  1-13. 

Shell.— Delicate,  brittle,  surface  with  minute  inc.,n^,i(MiMUs  >ln.rt 
ridges  more  or  less  radially  disposed,  and  studded  with  small  tul.er- 
cles3.  The  sides  meet  at  a  rounded  angle  of  about  100°.  Sntural 
lamina-  small. 

Anterior  valve. — With    minute  scattered  tubercles,  which    | 
towards  the  apex  into  low  tubercular  ridges,  having  a  concentric 
arrangement. 

Intermediate  valves. — Central  areas:  The  minute  surface  ridges, 
when  visible,  are  longitudinally  disposed  on  the  jugum,  but  be. 
radial  or  oblique  on  the  pleura.  The  tubercles  are  round  on  the 
jugum,  but  becomeVomewhat  oval  on  the  pleura,  and  there  appear 
to&be  concentrically  arranged,  although  in  some  valves  they  seem 
to  more  or  less  regularly  diverge  from  the  apex.  Lateral  areas  : 
The  surface  ridges  are  radial  and  more  pronounced  than  elsewhere. 
On  the  upper  portion  of  the  areas  there  are  transverse  low  ri 
placed  further  apart  than  the  former  ;  these  ridges  by  bein-  inter- 
rupted gradually  pass  into  tubercles.  The  tubercles  are  round, 
distinctly  smaller  than  in  the  central  areas,  and  more  scattered. 

Posterior  valve.— With  a  small  central  umbo.  Anterior  an  a  : 
With  concentric  tubercles,  as  in  the  lateral  areas.  Posterior  area  : 
Similar  to  the  anterior  valve. 

Qirjle.__NarroWj  with  delicate  scales,  which  form  a  minute  fri 
at  the  edge. 

C0lolv_Greenish-white  with  one  or  two  irregular  reddish-brown 

flecks. 

Size.— Length,  8  mm. ;  breadth,  3..">  mm. 

Northern  7V//.V,  L«t.  35°  41'  N.,  long.  157°  4?  K..  i..  2300  fas. 

/..  henthus  HAD.,  ('hall.  K.-p.  xv,  p.  H>,  t.  1.  f.  1.  t.  2,  f. 

dills.— Seven  in  number,  extending  between  the  prominent  anu> 
and  postero-lateral  angle  of  the  foot.  The  gill  row  ifl  ..n.—venth 


10  LEPIDOPLEURU8. 

of  the  total  length  of  the  body,  the  proportion   with  regard  to  the 

n  <>t*  the  foot  is  1  :  4.5.     Tin  -y  are  of  moderate  size,  the  middle 

being  the  largest,  slightly  decreasing  behind  but  much  more  so  in 


L.  n  i  i  '.IN  \rt\s  Adams  <fc  Reeve.     PI.  4,  fig.  88. 

Shell  elongate,  elevated,  whitish,  tawny-ashen  sometimes  soiled  ; 
apices  *  T..I|«  •(!  ;  juirum  rounded.  Mucro  moderately  elevated,  posterior 
slope  very  concave  ;  jugal  area  hardly  defined  ;  central  area  hardly 
sculptured  ;  lateral  areas  quite  elevated,  frequently  sculptured  with 
irregular  concentric  incremental  wrinkles  ;  jugal  sinus  wide  and 
.-traiirht.  <  n'rdle  narrow,  very  thin,  thickly  covered  with  very  deli- 
cate small  and  fugacious  scales,  which  are  somewhat  elongated  and 
purpli>h.  (CJpr.)  Length  20,  breadth  9}  mill.  ;  divergence  90°. 

Korea. 

(  '1,,'tw,  fH/if/htntu*  AD.  &  RVE.,  Conch.  Icon.  t.  26,  f.  174,  1847.— 
Lept<><-Itit«)i  fnflf/inatus  A.  &  R.,  CPR.  ms.  p.  4,  5.  —  DALL,  Proc.  U. 
t.  MIIS.  1878,  p.  318,  316. 

This  specimen  is  an  approach  to  Stenoplax  in  its  outward  form 
and  the  character  of  its  girdle  covering.  The  scales  appear  smooth, 
ami  have  the  shape  of  those  of  Stenoplax.  It  has  a  curious  general 
resemblance  to  Trachydermon  albus,  but  the  absence  of  insertion 
plat*--  at  once  distinguishes  it.  The  concentric  furbelowing  at  the 
sides  i>  variable.  (Qor.  from  B.  M.  specimens.) 

See  remarks  under  L.  cancellatus  for  further  distinguishing  char- 
acters of  tli  is  species. 

I..  •  \ni.  1.1  •-  K«  ve.     PI.  4,  fig.  87. 

Shell  ovate,  attenuated  anteriorly;  terminal  valves  and  lateral 
areas  of  the  rest  concentrically  ridged,  radiated  with  minute  gran- 
uli-s  central  areas  very  finely  grooved  and  cancellated,  whitish,  liga- 
ment horny,  arenaceous  (Reeve.) 

Habitat  unknown. 

C.  catillus  Rv.  Conch.  Icon.  t.  23,  f.  159,  lS47.—Leptochiton 

...  CPB,  .UN.  p.  ii. 

Miu'ht    e;i>ily  IK-    taken  for   *trnmtnens  Sby.   outside.      Coarsely 

granose-1  irate,  like  the  Mogador  specimen  [L.  granoliratus]  ;  girdle 

gravelly.     The  sculpture  consists  of  longitudinal  granose  lira1  upon 

ami  radiating  gltmofe  lira-  upon  the  lateral  areas. 

No    insertion   plates,  but  the  line  of  them  is  rugose.     Length    9*, 

rgeooe  110°.     Jugum  rounded.     (Q?r.) 


ii  PIBOPL1  iKUS.  1  1 

L.  CONCINNU8  Gould.       I'njif/nrnL 

Shell  minute,  reddish,  elliptical,  vaulted,  all  over  punctate  [  LM 


lose],  the  points  arranged  in  radiating,  nirvmi:  B6rie0;  lateral  areas 
hardly  elevated,  longitudinally  waved,  l-'mut  valve  oretoentlC  : 
posterior  valve  with  an  acute  umbo,  concentrically  waved.  <  ,'mlle 
narrow,  buff.  (Old.)  Length  8,  breadth  r,  mill. 

Butural  plates  small,  subtriangular  ;  jugal  sinus  very  wide,  flat  ; 
scales  of  the  girdle  delicate.  (Qpr.) 

Hakodadi,  Japan,  laminarian  zone,  on  shells  and 

C.  (Leptochiton)  concinnus  GLD.,  Otia  Conch,  p.  117.  —  Lepto- 
chiton  concinnus  CPR.  MS.,  p.  3.  —  DALL,  Proc.  U.  S.  Nat.  Mu~.  p. 
318,  316,  1878. 

L.  NEXUS  Carpenter.     Unfigured. 

Shell  small,  whitish-ashen,  valves  gothic-arched  ;  lateral  areas 
scarcely  defined;  entire  surface  ornamented  with  series  of  sulujuad- 
rate  granules,  the  series  longitudinal  upon  the  central,  radiating 
upon  the  lateral  areas  and  end  valves,  very  close,  scarcely  inter- 
rupted. Jugum  elevated,  subacute;  umbones  inconspicuous.  Mucn. 
conspicuous,  median.  Inside  with  strong  sutural  lobes  and  a  wide 
plane  sinus  to  the  middle  valves;  insertion  plates  obsolete.  Girdle 
having  narrow,  close,  striated  scales  and  needle-shaped,  crystalline 
bristles  here  and  there  and  around  the  margin.  (Q?r.) 

Length  7s,  breadth  4£  mill.;  div.  90°. 

Catalina  Island,  California,  20-80  fins. 

Leptochiton  nexus  CPR.,  Rep.  Brit.  Asso.  Adv.  Sci.  for  1863,  p. 
650,1864;  Proc.  Cal.  Acad.  iii,  p.  212,  1866;  ms.  p.  2.—  DAM.. 
Proc.  U.  S.  Nat.  Mus.  1878,  p.  316,  319. 

A  variety  is  prettily  variegated  with  olive,  has  stronger  sculpt- 
ure, and  the  valves  slightly  beaked.  The  spicules  which  appear  on 
the  girdle  among  the  striated,  elongated  scales,  are  very  numerous. 
It  is  curiously  like  the  young  of  Ischnochiton  radians.  (Cpr.} 

See  notes  under  L.  cancellatus  for  comparison  with  that  species. 

L.  RUGATUS  Carpenter,  n.  sp.     PI.  3,  figs.  67-70. 

Oval,  rather  convex,  the  lateral  slopes  nearly  straight,  doi-al 
ridge  broadly  arched.  Front  and  back  valves  and  lateral  areas  of 
the  intermediate  valves  sculptured  with  excessively  fine  radiating 
striae  which  are  feebly  granose,  and  having  well-marked,  coarse,  con- 
centric wrinkles;  central  areas  having  an  equally  minute  sculpture 


ll*  LEPIDOPLEUBU8, 

of  longitudinal  Bubgnuno0e  striae.     Macro  sabcentral  ami  prominent. 
Tlit-  lateral  areas  are  slightly  ra: 

\.  bivadth  7  mill.;  <livergence  100°. 
i/.  .-•  ray,  ''<//..  t»  T<><1».<  Santos  Bay,  L.  C<tHf»rn'i<t. 

/..     ft  rntj'itn.4  (  'i'i:.    .U.S.,  p.  3. 

This  form  resembles  somewhat  the  7>.  granolirotiu,  but  it  is  much 
finely  -culptinvd.  the  arch  of  the  valves  is   narrower   and   the 
al  areas  are  less  stnmirly  marked   by   concentric-  wrinkles.     It 
i--  likely   that  (lie  following  is  merely  the  young  of  this,  but  I  have 
not  Keen  able  to  compare  typical  specimens  of  internexus. 

L.  i\  irpenter. 

Sh»-ll  similar  to  L.  nexus,  but  much  smaller,  orange  colored. 
Valve-  i.  -iilarly  arcuate,  without  jugum.  Sutural  plates  small, 
triangular:  sinus  larger.  Girdle  with  more  solid  scales,  scarcely 
pilose,  i  ( >-.)  Length  41,  breadth  .31  mill.;  div.  90°. 

Santa  Barbara,  O.///Vor///'/. 

A.  inh-rnexus  CPR.  MS.,  p.  3. 

L.  CERGl  iii  \MS  Haddon.     PI.  1,  figs.  14-17. 

Shell. — Minute,  smooth,  or  with  scattered  minute  tubercles  ;  the 
-idi-  meet  at  an  aii.irle  of  about  100°;  sutural  lamina'  small,  tri- 
anirular. 

Anterior  valve. — Small,  smooth,  with  scattered  aborted  tubercles. 

Int'Tinediate  valves. — (V-ntral  area  smooth,  with  very  faint  longi- 
tudinal >tri;e;  lateral  areas  scarcely  discernible,  with  faint  radial 
-tri:e  and  minute  concentric  interrupted  ridges  towards  the  apex, 
which  pa>-  into  inconspicuous  small  scattered  tubercles. 

I1  sterior  valve. — With  full  rounded  umbo,  behind  which  is  a 
>hall«)\\  d<  presHon.  Anterior  area  :  similar  to  the  central  areas  of 
the  intermediate  valves.  Posterior  area  similar  to  the  anterior 
val- 

(iiidlc. — Narrow,  with  delicate  scales. 

<  '"lor. — rniform  whitish. 

.  —  Length  3,  breadth  !'."»   mill. 

<  iills. —  Posterior,  «  i-ht  or  nine  in  number  (Haddon.} 

Balfour  Bay,  Royal  tfnun<l.  Kerguelen,  60  fms. 
L.  I:-  r./nelensis  HAD.,  Challenger  Hep.  xv,  p.  12,  t.  1,  f.  3;  t.  *J.  t. 
3a-3e. 

L.  PAOl  R8TB  HER]   rf.-li:-i.      I'I.  '2,  figs.  39-40. 

Shell     .  •l-shapfil,    with    the    dorsal    anirlc    rounded; 

red   \\ith  a   tine,  indistinct,  irregular  granulation,  without  dif- 


LEPIDO]  ]:; 

entialed  areas.      Middle    valves  With  fifaorl    but  higb    lUtUIttl  pl« 

IK»  insertion  plate-  ;   sinus  larj-e  :IIH|  deep  ;    tin-  divi-i-.n  of  tl, 
mid    lateral  areas  is   marked  in>ide   l.\   :(    .-.liirlit  ._.  . 

margin  «.r  the  anterior   valve  i<  semicircular,  MM-  posterior  mai 

meeting  ;il  MII  angle  <'f  l.'.n  '.      The  po.-terior  margin  of  the 
vnlvc  is  about  tin-    third    of  a  circle,  itfi    In.  nt    111:11 
above  a-  a  >traight  line.      The  miicro   is  >nl.eenl  ral,  .-omewhat    D 
t'orxvard  than  lichind. 

Tlit'  color  ot'tlic  valves  is  a  pale  irray-liniwn.  irre-jularK 
witli    brown    dots  which    are  lacking  at  the    margins,  l'-a\; 
a  paler,  unicoh.i-ed  /(.no.     The  girdle  is  brownish,  the  scales  white. 
The    length   cannot    be   given    exactly,  as   all    the    >pecinien-   \\  ••!••• 
strongly    rolled    up;  but    the   maximum    length  seemed    to    l.e    1-7, 
breadth  of  the  shell  2';")  of  the  girdle  O8  mill.     (/;/fr.). 


Leptochiton  pagenstecheri  PFFR.,  Jahrb.  Hamburg.  \Vi.--en- 
schat't  lichen  AnstaJten,  iii  Jahrgang,  p.  107,  t.  3,  f.  3,  1  - 

L.  ASELLU8  Spongier.     PI.  3,  figs.  64,  65,  66. 

Shell  small,  rather  elevated,  the  dorsal  ridge  bluntly  angular. 
Very  minutely  and  evenly,  but  rather  indistinctly,  lirate-granulate; 
olive-ashen,  often  having  longitudinal  delicate  pencilings  of  olive- 
green. 

Anterior  valve  very  densely,  minutely  and  evenly  granulated, 
the  granules  being  irregularly,  but  usually  visibly,  arranged  in  radi- 
ating rows  ;  the  peripheral  third  of  the  valve  having  coarse  concen- 
tric wrinkles. 

Intermediate  valves  have  the  central  areas  finely  densely  longi- 
tudinally granose-lirate.  Lateral  areas  closely  granose,  the  granules 
arranged  in  radiating  rows  on  the  lower  portions,  which  are  also 
wrinkled  like  the  anterior  and  posterior  valves.  The  lateral  areas 
are  separated  from  the  central  area  by  an  inconspicuous  low  ridge. 

Posterior  valve  with  subcentral,  rather  low  umbo,  the  posterior 
slope  concave.  Interior  of  valves  white;  sutural  plates  small. 

Lofoten  Is.,  Norway,  Iceland  and  Greenland,  *out/i  to  d'u/j  »f 
Gascony. 

Chiton  asellus  SIM:N<;I.I:R,  Skriv.  Nat.  Solsk.  17(.»7,  vol.   iv.  j.. 
—  LOWE,  Zool.  Journ.  ii,  p.   101,  t.  5,  f.  3,  4,    1825.  —  BROWN: 
DESHAYES  in  LAMARCK  An.  s.  Vert.  ;  MII>IH-:NI><>I:I  i  :   FORBEB  <$ 
1  1.  \\LEY,  Brit.  Moll.  vol.  ii,  p.  407,  t.  f>!>,  f.   1,   '_'.  —  Chiton   tiiiniinn.< 
(  'IIKMNIT/;      WOOD;     DILI.WYN.  —  Chiton     cinereu*     MONTAGU; 


14 


:  K'I.IVI  :  LoYEN;  JEFFREYS,  Brit.  Conch,  vol.  iii,  p. 
218,  v.  p.  108,  t.  56,  f.  •_'  :  I'.  Z.  S.  1882,  p.  668.,  non  LINNI:.  teste 
II  \\IIY.  Ip-.  Lin.  Conch,  p.  17.  —  Lepioehiton  cinereus  GRAY,  P. 
1*47.  p.  127,  !»;*  •  var.  white,  C.  "'albus  "  exclus.)  as  type  of 
genus.  —  J.fjitnrhitnu  nuel/unli.&A.  ADAMS,  (Jen.  i,  )>.  473.  —  GRAY, 
Guide,  p.  182.—  Cn:.  *•*  p.  2.—  BALL,  I'roc.  T.  S.  Nat.  Mus.  1878, 
p.  318.  —  /  Lein'il<']>!'  unit  cinereus  L.,  SARS.,  Moll.  Reg.  Arct.Norv. 
p.  ll'J.  t.  7.  f.  *.—  Chiton  ittandicn*  <iMi:i,.,  Syst.  p.  3206.  —  C.  fus- 
catus  Li  LOB,  D(H  l.n.wn.  —  C.  scoticus  LEAC-II,  teste  Jeffr.  —  C.  onyx 
K.  Skrivteraf  Natnrhi.-torie-Selskabet  (Udforlig  Be  Skri- 
velse  over  det  mangeskallede  Conchylie  Slaegt  af  Linne  kaldet 
(  hitun  ined  endeel  nye  Arter  og  Varietat)  Oplaest,  28  Febr.,  17!>4. 
iv.  1  Heft.  P.  «;•_',  17!»7  rf.  Mai.  HI.  xvii,  p.  113. 

This  >j>ccies  is  allied  to  L.  granoliratus  Cpr.,  but  that  is  more 

t«  .1.  the  central  and  lateral  areas  are  more  diverse  in  sculpture, 

and  the  concentric  wrinkles  are  much  stronger.     In  L.  cancellnttt* 

the  lateral  areas  are  raised,  which  is  not  the  case  with  the  asellus. 

"Under  the  microscope  this  species  can  easily  be  separated  from 

;i.       iixirginatus  Jeffr.)  by  external  characters.     In  the 

nnon  the  scales  are  very  minute,  smooth,  granular,  reddish 

and  closely  appressed  to  the  girdle;    in  the  Leptochiton  they  are 

gravel  like,  irregularly  crowded,  larger,  lengthened  and  striated.    In 

I,  also,  the  valves  are  more  beaked,  especially  in  young 

shells." 


L.  '.I:\NOI.H:  \n  >  Carpenter,  n.  sp.     PI.  2,  figs.  47-53. 

Shell  oval,  rather  h»w  and  regularly  convex,  not  angulated  d<>r- 
sally.  Very  finely  and  closely  granose-lirate,  the  anterior  and  pos- 
terior valves,  and  the  lateral  areas  of  the  median  valves  strongly 
c.,rnii:ati-d  c.mrrntrieally.  Color  "ashen-orange"  or  fleshy-ashen, 
with  an  ill-dHim-d  darker  dorsal  stripe. 

,nt«-rinr  valve,  ;md  the  lateral  areas  of  the  intermediate  valves 
,11.  ly  radially  granose,  and  have  a  number  of  strong  concentric 
wrink!«>.     The   central    areas  have  close  fine  subgranose  longitud- 
inal lira-.     The  lateral  areas  are  slightly  raised. 

I'mho  of  the  posterior  valve  somewhat  in  front  of  the  middle, 
rather  prominent  ;  posterior  slope  concave,  radiately  granose-lirate 
and  strongly,  irregularly,  concentrically  wrinkled. 


LBPIDOP1  i  '   1:1  -.  10 

(iirdle    narrow,  rl<»>rly    hr.-et    with    delicate    •  '. 

•oales, 

LniLrth   10,  hivadth  7  mill.;  <li ver^enec  l.'JQ0. 

.    M 
/.(•/•tni'lu'tun  1/rnnnfiriifiiit  Cri:.  MX.  p.  3. 

This  speries  may  easily  be  distinguished  from  L.  «/.w/i/ 

strniii:   emieentrir    wrinkles   and    the   low,    n.uiulcd    arching   of  the 

back. 

L.  CAJETANUS  Poli.     PL  2,  figs.  41-46. 

Shell  oblong,  elevated,  solid.  Valves  regularly  arched,  the  lateral 
areas  very  strongly  raised,  coarsely  sculptured. 

The  median  areas  of  the  valves  are  sculptured  with  longitudinal 
lira?,  which  are  gniiiulous  and  anastomose  or  branch  irregularly. 
The  head  valve  lias  strong  concentric  ridges,  7  to  10  in  number  in 
adults,  the  intervals  being  finely  pitted  or  granose.  The  lateral 
areas  of  the  intermediate  valves  are  very  much  raised,  and  sculp- 
tured with  concentric  ridges  like  the  head  valve.  The  posterior 
valve  is  very  solid  and  thick,  its  apex  posterior  but  recurved  for- 
ward and  much  elevated;  its  posterior  slope  is  subvertical,  convex, 
terraced. 

The  sutural  plates  are  triangular  and  stout;  the  jugal  sinus 
rather  narrow.  Insertion  plates  are  completely  lacking.  It  is 
lusterless,  and  light  buff  in  color. 

Girdle  very  narrow  and  thin,  bearing  most  minute,  close  delicate 
deciduous  scales. 

Length  23,  breadth  12  mill. 

Length  11,  breadth  6£  mill. 

Mediterranean  and  Adriatic  Seas;  Atlantic  Ocean  from  Cape 
Breton  to  the  Gulf  of  Gascony ;  Canaries ;  Pliocene  of  Biot  (Mar- 
itime Alps'),  of  Calabria  and  Modenais;  Pleistocene  of  Monte 
Pellegrino. 

Ch.  cajetanus  POLI,  Test.  utr.  Sicil.,  i,  t.  4,  f.  1,  2,  1791.— Pin  i.. 
Enum.  Moll.  Sicil.  i,  p.   108,  ii,  p.  83. — WEINKAUFF,  Conch,   des 
Mittelm,  ii,  p.  412. — REEVE,  Conch,  Icon.  f.  171. — Lepidopl> 
cayetanus  Poli,  Risso,  Hist.  Eur.  Merid.  iv,  p.  267. —  Ch.  cult" 
Poli,  JEFFR.,  P.  Z.  S.  1882,  p.  QQ7.—Leptochiton  cuj'.'tnnu*   Poli, 
CPR.  mss.  p.  7. — Holochiton  cajetanus  Poli,  BUQUOY,  DAUT/I  \  i 
and  DOLLFUS,  Moll.  Mar.   Roussillou,  i,  p.  500,  t.  61,  f.  1-3  ;  i 
f.  5. 


16  LEPIDOPLEUBU8, 

In  -culpture    tliis   sp  -trikinirly    different   from  the  other 

and  in  fact  from  all  other  Chitons.     The  lateral  areas 

ami  front  \:il ,  -1,  the  latter  being  compared  by 

ater  to  a  circular  flight  <»f  nmndcd  >irps. 

The  Atlantic  >p,  cinieii^    arc  always   larger  than    those   from  the 
.  the  measurement*  Jird  given  above  being  taken  from 
an  Ocean  example,  the  second  measurements  from   an  Italian  speci- 
men. 

It  i-  the  i  llisso's  genii-  Lepidopleurui. 

;ion  Deshayesiff/'t  Carpenter,  1878. 

Deshayesiei/'i  CAKI-IMKR  mss.,  p.   10. — DALL,  Proc.  I  .  S.  Nat. 
;..    :I14;  l.<:    1882,   p.   286.— HADDON,   'Challenger' 
IV.lyplacophora,  p.  9. 

Shdl  ehm-ated:  valves  curved,  somewhat  beaked;  umbo  flat- 
tened: m>  insertion  plates ;  sutural  plates,  triangular  ;  girdle  spicu- 
lose. 

Ditli-i>  from  L<i>tochiton  not  only  in  its  hairy  girdle  but  al>o  in 
':itt«-m-d  iimlio  and  its  valves,  which  are  somewhat  thrown  for- 
um d,  forming  a  decided  transition  toward  some  of  the  palaeozoic 
forms. 


L.  .  i  KV  kTOH  Carpenter,  n.  sp.     PL  4,  figs.  78,79,  80,  81. 

Shell     rather    elongated,  whitish-ashen,    planate ;    dorsal    ridge 
rounded  ;  umho  central,  flat;  valves  with  pointed  apices,  all  curved  ; 
the  interior  .if  the  posterior  part  of  each  valve  much  scooped   out. 
Jugal  area  broadly  V-shaped,  </m/x/  reticulated,  the   lines  of  pus- 
tules parallel  in  the  middle,  diverging  at  the  sides,  interstices  pnnc- 
( 'ei.tral  areas  with  longitudinal  distant,  beaded  lines,  8  to  10 
ach  side,  tt -ndinur  toward  the  juguin  forward,  interstices  decus- 
al  areas  somewhat   swollen,  expanded,  but  scarcely 
•  •d  by  a  line  from  the  central  areas;  coarsely,  irregularly  gran- 
oee,  and  concentrically  waved. 

lu-ide:  insertion  plates  absent,  the  position   of  them  flat:  sinus 
l.r-.a.l.  t'..ll«»wiiiLr  the  curvature  of  the  valve. 

<iirdlr   delicate,  clothed  with  small  scattered  spines,  occasionally 
larger,  and  chafi'y  lealat.     (Cjpr.) 

Length  1  1,  l.readtl.  15.1   mill.;  div.  120°. 

./'tjnin  (A.  Adams). 


II.\M.I:V\.  17 

(Detkayesiella)  curvatut  < 'pr..    DAI.I,.    IY<>r.    I 

N:i1.    Mil-..   1*7*.  p.    •"•IMname    ami     -jeiier'n-    e! 

Dtthayetiella  curvata  c/ir.  ,l/.sf.  p.  lo. 

This  shell  externally  looks  very  niiieh  like  an  .  I "//,//, o'7, /'/<,// 
without  the  pore  hunches,  of  \\hieh  there  i<  no  trace.  The  plam  d 
oil'  parts  inside  the  apices  are  unusually  large.  (Q>r.) 

Genus  II.  IIANLKYA  Gray,  1857, 

Hanfcya  GBAY,  Guide  Syst.  Di>t.  Moll.  P..  M.,  p.  186,  type"//. 
debilis  Gray—  Chiton  h«n/<-i/i  Thorpe." — Hnn.leyia  DAM.,  and  Il<n,- 
lei<t  of  (1ARri:vn.i:,  J/N. 

Anterior  valve  having  an  insertion  plate  without  slits,  but  rough- 
ened ;  intermediate  and  posterior  valves  having  no  insertion  ph 
eaves  small;  girdle  with  iine  spines  ;  no  girdle  pores. 

This  genus  differs  from  Leptochifon  and  Dethayesiella  in 
ing  an   insertion   plate  upon    the  anterior  valve.     It  differs  from 
Hemiarthrum  and  Mlcroplax  in  having  no  insertion  plates  upon  the 
intermediate  and  posterior  valves,  and  in  lacking  girdle  pores. 

In  Dr.  Gray's  original  generic  diagnosis,  the  girdle  is  said  to 
have  pores  furnished  with  tufts  of  bristles.  This  has  proved  to  be 
an  error,  the  statement  evidently  having  been  based  upon  a  speci- 
men in  which  the  girdle  was  transversely  wrinkled,  throwing  the 
bristles  into  close  groups. 

H.  HANLEYI  Bean.     PI.  3,  figs.  71-79. 

Shell  oblong,  convex,  the  lateral  slopes  nearly  straight,  the  dorsal 
ridge  rather  angular.  Sculpture  consisting  of  numerous  rounded 
tubercles,  arranged  in  longitudinal  rows  on  the  central  areas,  the 
series  of  tubercles  finer  and  closer  upon  the  jugum  ;  head  plate  and 
lateral  areas  having  coarser  rather  irregular  tubercles.  The  lateral 
areas  are  not  raised.  The  mucro  is  median,  rather  elevated. 

The  plates  of  insertion  of  posterior  and  intermediate  valves  are 
obsolete,  edges  roughened  ;  anterior  valve  having  a  short,  acute 
insertion  plate,  outwardly  rugose-sulcate,  the  sulci  indenting,  but 
scarcely  slitting  the  margin.  Sutural  plates  moderate;  sinus  v«-ry 
wide,  denticulated  by  the  sculpture  of  the  outside.  Eaves  vei  y 
small. 

Girdle  narrow,  beset  with   numerous  short  and   longer  horn-col- 
ored spicules.     Length  10,  breadth  5  mill.,  sometimes  larger. 
2 


IIAM.KYA. 

British  seas  iiorfhn-"          v  ^f<^f/eroe,  near  North  Cape, 

1  fms. ;  Stdlwdrjeti  Hunk,  Massachusetts  Bay,  in  38 /MS. 
Chiton  h>t/tl  suppl.  to  Thorpe's  Brit.  Mar.  Conch,  p.  _ 

and    HAM. KY.  Hist.    P.rit.    Moll,  ii,  p.  398,  t. 

.-.lini:..  IJrit.   Condi,  iii,  p.  215;  v,  p.  198,  t.  55,  f.  s.— 

5,  Moll.  ]  .   Norv.  p.  109,  t.  7,  f.  5. — Hanleia  hanleyi 

P..  an,  Cri:.  mss.  p.  8. — llanleiia  dcbilis  GRAY,  Guide,  p.  186,  ]x~>7. 

//     ,  •";/,/  dclUls  Cray,  DAI.I..  PrOC.  I".  8,  Nat.  Mns.  1*7*,  p.  319. 

•"//(//•  LUVKN,  Ind.  Moll.,  p.  I'll. 

This  spi-cii's   has   been    reporti-d    tVoin   Palermo   by  Monterosato 
'.!o,,r.  dr  Conch.  1878,  p.  147). 

Yar.   LBY88ORUM  M.   Sars.     PI.  4,  figs.  74,  75,  7d,  77. 

Closely  allied  to  //.  h'tiJciii,  but  more  than  double  the  size,  hav- 
ing thr  -mile  \vidor  and    thicker,  spicules  shorter;  shell  narrower, 
with  !«•>>   distinct   sculpture.     Pale  brown,  the  girdle  flesh-brown. 
jth  :;t  mill.     fS.trs.') 

Bergen,  Xorway,  150-200  fms. 

Ch.  abyssoruiii  >F.  Sars,  G.  O.  SARS,  Moll.  Reg.  Arct.  Norv.  p. 
.  t.  7,  f.  4;  t.  34,  f.  3. 

H.  MI:M.I« -AIIIA  Mi-hels  vV  Adams.     PL  4,  figs.  82,  83,  84,  85. 

Shell  oblong-oval,  not  much  elevated,  dorsal  ridge  obtuse,  lateral 

elopes  flattened ;  ashen-white,  the  entire  surface  granulated,  gran- 

!y  crowded,  forming  longitudinal  series,  about  20  on  each 

>id«-:  lateral  areas  ha  idly  defined,  irregularly  granulated,  the  granules 

larger.     .luirum  scarcely  defined,  broadly   vaulted.     Mucro   low   or 

:  al. 

Interior  having  a  solid,  rather  acute,  but  scarcely  fissured  inser- 
tion plate  to  the  anterior  valve  ;  none  upon  the  central  and  posterior 
valve.-.  Sutiiral  plates  lariro,  subtriangular ;  sinus  simple,  wide, 
scarcely  laminate.  Kaves  wide.  Girdle  wide,  solid,  leathery, 
finely  Spiculate,  the  spicules  glassy,  here  and  there  crowded; 
no  p 

<  Jills  posterior,  about  \~>  on  each  side. 

•i_rth  1  "»,  hr.-adtli  85  mill.;  divergence  123°. 
Length  1th  15  mill.;  divergence  108°.     (Q?r.) 

Casco  B<i>,,  r<n-t/>nnl  llarhur  <ind  Grand  MuiKtn,  M '» 

If,  A   A..  Bo«t.  .lourn.  N.  II.  iv,  p.  42,  t,  4,  f. 

8,  1>  -I. i.,  Inv.-rt.  of  Ma.s..   P.inney's  Edit,  p.  2(>3,  f.  526.— 

M  ..  ii..  -1 1:1  ••!••]:.,  P.   /.  S.   1882? 


IM.MI  MM  IIIMM.  Hi 

j>.  <5H7.-  •  Hanky ia mtndicaria  CPU.,   N.  Km:.  Oiitim.--,  Ann.   I 

N.  II.-  I:  xiii,  ',,.  iL'l  ;  .J/X.,  ,,.!),  10.— DAI. I,,  PrOC,  I  tfuB. 

1878,  p.  319. 

H.  TROPICALffi  Dull.     PI.  6,  figs.  12-18. 

Chiton  about  !<)•()  nun.  in  K-n^tli  and  .">•()  nun.  in  width,  with  the 
usual  characters  of  the  genus,  i.  e.,  anterior  valve  with  an  un-lit 
insertion  plate,  other  valves  without  even  the  plates;  hack  with  an 
angle  of  about  90°.  Girdle  (fig.  13)  in  the  dried  specimens,  thin, 
narrow,  covered  with  close-set,  white,  glassy,  slender  spine-  •  1-n  I  -."> 
nun.  in  length)  above,  and  below  with  similar  but  much  shorter 
ones.  Anterior  valve  with  a  well-marked  mucro,  from  which 
proceed  concentric  striae  of  growth,  and  in  front  of  which  the  valve 
is  a  little  concave  ;  sculpture  of  little  less  tesselated  flattened  nodules 
radiating  from  the  mucro,  above  which  are  irregularly  distributed 
small,  opaque,  white  pustular  bubbles  of  shelly  matter  looking  like 
attached  grains  of  coral  sand ;  posterior  valve  smaller,  flatter,  with 
similar  sculpture,  but  the  pustules  take  on  a  decidedly  cylindrical 
shape  and  are  elongated,  looking  like  the  stalks  of  decapitated 
mushrooms;  this  arrangement  is  still  more  marked  on  the  posterior 
lateral  areas  of  the  intermediate  valves,  the  anterior  lateral  areas 
also  exhibit  (less  prominently),  but  with  an  obliquely  anteropos- 
terior  radiation,  while  the  former  have  it  more  entirely  lateral  from 
the  mucrones ;  dorsal  areas  with  the  tesselated  sculpture  alone, 
arranged  longitudinally.  Color  entirely  white. 

Sand  Key,  Florida,  in  128  fms. 

Hanleyia  tropicalis  DALL,  Bull.  Mus.  Comp.  Zool.  ix,  p.  53, 1881 ; 
< Blake'  Gastrop.  p.  415,  t.  26,  f.  8c,  8d ;  Bull.  U.  S.  Nat.  Mus.  No. 
37,  p.  172,  t.  26,  f.  8c,  8d. 

Genus  III.   HEMIARTHRUM   Carpenter,  1876. 

Hemiarthrum  CPR.,  in  Dall's  Moll,  of  Kerguelen  I.,  Bull.  U.  S. 
Nat.  Mus.  ii,  1876,  p.  44. 

Head  and  tail  valves  having  smooth,  unslit  insertion  plates,  the 
intermediate  plates  lacking  them.  Eaves  minute.  Sinus  broad  and 
spongy.  Girdle  solid,  downy,  poriferous,  the  lateral  tufts  small. 
Gills  short. 

Differs  from  all  the  preceding  genera  in  having  both  head  and 
tail  valves  provided  with  insertion  plates,  and  in  the  poriferous 
girdle. 


20  HEMIARTH1MM. 

II.  BBTULOSUH  Carpenter.     PL  5,  figs.  89-100;  1-8. 

The  color  of  the  shell  is  a  uniform  warm  dark  brown,  and  the 
girdle  is  chestnut  brown,  with  a  pale  crenulated  border  round  the 
margin  of  tin-  valves.  In  each  of  the  dark  triangular  bays  between 
tin-  valve-  i-  a  .-mail  tuft  of  short  white  spicular  scales,  and  there  are 
imilar  tufts  round  the  anterior  border  of  the  first  valve.  The 
anterior  and  po>trrior  valves  and  the  lateral  areas  of  the  inter- 
mediate valves  are  marked  by  concentric  lines  of  growth,  otherwise 
the  latter  are  scarcely  discernible.  The  jugum  is  very  gently 
rounded,  so  that  the  pleura  are  slightly  depressed.  The  unslit  in- 
sertion plate  of  the  anterior  and  posterior  valves  is  shown  in  figs. 
90,  94,  and  4.  ~>,  (\.  The  girdle  (fig.  98)  is  thick  and  soft,  with  a 
minute  scattered  scales.  There  is  a  distinct  fringe  of  reddish 
brown  elongated  striated  scales  round  the  margin.  The  scales 
forming  the  tufts  are  stout,  and  white  in  color.  Carpenter  describes 
the  anterior  tufts  as  about  four  in  number;  in  my  specimen  there 
are  -i\  anterior  tufts.  Evidently  Carpenter  was  not  quite  satisfied 
on  this  point,  as  in  all  other  Chitons  which  possess  tufts,  only  four 
are  p resent;  and,  consequently,  that  number  might  be  expected  to 
occur  in  this  species  also.  The  head  lappets  are  rather  large,  and 
the  anus  is  on  a  large  rounded  papilla.  The  longitudinal  band  on 
the  under  side  of  the  girdle  (veil  of  Carpenter)  is  produced  into  flaps 
at  the  po.-terior  extremity. 

Tin-  Lrill>  rjil.  .">,  figs.  1,  99,  100,  7),  form  a  short  posterior  row, 
and  appear  to  be  about  six  in  number;  they  decrease  in  size  anttr- 
iorly. 

Length  '.)  mm. ;  breadth  4  mm. ;  side  of  valves  meet  at  an  angle 
of  about  115°.  (Haddon.) 

Length  i:1,,  width  7  mill.     (Q?r.) 

Kerguelen  Island,  on  stones  at  low  water  (Kidder);  and  Royal 
Sound  on  shore  ('  Challenger ') ;  South  Georgia  (Pffr). 

Hemi'irthrum  setn/nsnm  CARPENTER  1/&,  p.  13. — DALL,  Bull.  U. 

it.  Mus.  ii,  l>7'i.  p.  44.— HADDON,'  Challenger  'Poly  placophora, 
p.  11.  t.  1.  f.  1  :  t.  L'.  i'.  4a-l. — MAI.-TKNS  and  PFKI -FKK,  Jahrb.  der 
llambnrgischen  Wissenschaftlichen  Austalten  iii,  p.  ]08,  t.  .'),  f.  4, 
1886, 

The  specimens  from  S.  Georgia  were  much   eroded  ;  they  meas- 
:  about  s-ll  mill.,  and  were  when  alive,  ''brown-black  almost 
blaek.  "     One  of  these  is  figured  on  pi.  5,  figs.  1,  2,  3. 


MI<  HOI-LAX.  LM 

This  shell,  externally,  resembles  <ome  n\'  the  ooane,  ill-defined 
Aranthochitons.  The  girdle,  however,  is  narrower  ;m«l  Muooth<-r 
than  in  that  -jenus,  and  the  pores  so  extremely  minute  that  in  a  dry 
specimen  they  would  escape  attention.  Within,  however,  the 
features  are  entirely  new  though  not  unexpected.  It  forms  a  tran- 
sition between  Hanleya  (mendicaria)  and  the  articulate  chitons.  A 
single  unslit  lamina  surrounds  both  the  terminal  valves,  projecting 
far  beyond  the  external  layer.  In  the  posterior  plate  this  is  con- 
tinued forward  to  form  part  of  the  sutural  laminie.  These  in  all 
the  valves  slope  off  both  toward  the  middle  and  toward  the  sides,  so 
as  to  take  the  place  of  the  ordinary  side-lamina3,  which  here  do  not 
exist. 

Genus  IV.  MICROPLAX  Adams  &  Angas,  1864. 

Microplax  H.  AD.  &  ANG.,  Proc.  Zool.  Soc.  1864,  p.  194,  type  M. 
gniyi  Ad.  &  Ang. — CARPENTER  MS.,  p.  12. 

Insertion  plates  smooth  and  thin,  present  in  all  the  valves.  Sut- 
ural plates  obsolete,  the  sinus  extremely  shallow.  Girdle  thin, 
horny,  most  minutely  granulous.  Valves  largely  concealed  in  the 
girdle,  the  exposed  portions  small  and  separated. 

In  the  present  genus  a  small  portion  only  of  each  valve  is  exposed  ; 
and  the  sutural  plates  and  sinus  are  obsolete.  No  other  Chiton 
having  unslit  insertion  plates  approaches  this  remarkable  group. 

M.  GRAYI  Adams  and  Angas.     PI.  6,  figs.  9,  10,  11. 

Shell  elongated,  convex,  brown  ;  exposed  portion  of  the  valves 
minute,  wide  heart-shaped,  carinated,  strongly  granulated,  the  inter- 
vals between  the  exposed  parts  of  the  valves  about  as  long  as  the 
latter.  Lateral  areas  defined  by  a  distinct  rib.  Girdle  moderate, 
corneous,  smooth  (A.  and  ^4).  Length  13,  width  5  mill. 

Sydney  Harbor,  Australia,  under  stones  at  low  water. 

Microplax  grayi  H.  AD.  and  ANG.,  P.  Z.  S.  1864,  p.  194,  /.  c. 
1865,  p.  58,  t.  11,  f.  16.— ANGAS,  P.  Z.  S.  1867,  p.  224.— CARPEN- 
TER MS.,  p.  12. 

The  figures  given  were  drawn  by  Mr.  E.  A.  Smith  from  the  type 
specimen. 

Carpenter's  notes  upon  the  unique  specimen  in  coll.  H.  Adams 
are  as  follows:  It  is 'quite  transparent,  looking  like  thin  horn. 
There  are  very  slight  overlappings  of  the  valves,  corresponding  to 


22 

the  sutural  lamina-,  hut  no  slits  at  all  are  to  be  seen.  The  lamina? 
are  very  square.  n..t  wavy  as  in  the  other  covered  species.  There 
is  a  very  slight  indication  of  riblets  or  strife  continuing  from  the 
•  nal  rili  do\\  n  to  the  edge  of  the  lamina,  but  I  cannot  see  the 
least  indication  of  nicks  or  lobes  at  the  edge.  The  sutural  lamina- 
are  extremely  slight,  projecting  over  each  other  about  to  the  line 
of  the  mucro,  with  the  very  -li-lite-t  sinus  in  the  middle  between 
them. 

The  front  valve  is  horse-shoe  shaped,  with  flat  base,  mucro  a 
little  removed  from  the  margin.  It  is  nearly  smooth  at  the  mucro, 
becoming  gradually  more  granulose.  The  whole  color  is  a  greenish 
pink. 

The  intermediate  valves  all  point  forward;  their  mucrones  in  no 
case  touch  the  posterior  edges ;  two  smooth,  diagonal  ribs,  curved 
forwards,  separate  the  lateral  and  central  areas,  both  of  which  are 
jr  ran  u  lose. 

The  posterior  valve  has  the  mucro  a  little  anterior,  the  two 
oblique  ribs  curving  backwards. 

It  will  be  noted  that  the  umbo  or  mucro  in  the  posterior  valve  is 
directed  forward,  whilst  in  the  other  valves  it  is,  as  usual,  directed 
1  »ack  wards. 

The  divergence  is  76°,  very  elevated.  The  exposed  part  of  the 
valves  measure  about  1J  X  If  mill.  The  girdle  is  everywhere 
minutely  granular — too  minutely  to  be  shown  in  the  illustration. 


I'a.nily    CHITONIDJS, 

— Ischnoidea  -j-  Lop/ii/rnidcn  -,   AoaniAoufoaof  CARPBVTEB.      / 

n<r/i,'t<»ii<l<r,  Lu^hijritli-  and  Arnnffinji/cnridir  I).\l,i.,   lilal 

poda,  p.  -11"),  IK!.    -Lophyochitonidcc,  Chcetochiionida  and 

('hftoiu'ilir  K<><  in  r.iMM,,  Miss.  Sci.  du  ( 'aj>  Horn,  vi,  /ool.,  j..  '  1 :;  I 

l-l.",,  L889.— CA&m  L.,  FISCHER,  Manual,  p.  879. 

Chitons  in  which  all  of  the  valves  pOMeta  insertion-plates  -lit 
into  teeth;  the  insertion-plate  of  the  tail  valve  similar  to  that  of 
the  head  valve.  Eaves  developed. 

The  conclusion  has  been  forced  upon  me  that  the- three  divisions 
B,  Ischnoidea,  C,  Lophyroidea,  D,  Acanthoidea  of  Carpenter's 
arrangement  cannot  be  separated  by  sufficiently  definite  characters 
to  give  them  the  rank  of  families.  The  Ischnoidea  blend  with  the 
Lophyroidea  through  certain  species  of  Chcetopleura,  Tonicella  and 
Tonicia ;  and  the  connection  with  those  Acanthoidea  having  Isch- 
noid  insertion  plates  is  even  closer.  It  is  by  no  means  certain  that 
the  Acanthoidea  constitute  a  natural  group;  the  portion  having 
pectinated  insertion  plates  may  prove  more  closely  allied  to  the 
true  Chitons  (Lophyroidea),  whilst  those  with  sharp,  smooth  inser- 
tion plates  would  hold  a  like  relation  to  the  Ischnoidea.  It  is,  in 
fact,  not  an  easy  matter  to  decide  whether  such  genera  as  Callisto- 
chiton  and  Pallochiton  belong  to  the  Ischnoid  or  the  Acanthoid 
series,  Carpenter  referring  them  to  the  former,  whilst  my  own  stud- 
ies cause  me  to  place  them  in  the  last  named  group. 

In  the  present  work  I  have  concluded  to  recognize  Carpenter's 
three  divisions  as  subfamilies,  believing  it  better  to  retain  a  classifi- 
cation admitted  to  be  faulty  than  to  institute  radical  changes  which 
I  am  at  present  unable  to  place  upon  an  indisputable  basis.  The 
regular  Chitons  having  slit  insertion  plates  may  therefore  be  divided 
into  the  following  three 

Subfamilies : 

Subfamily  ISCHNOCHITONIN^E.  Insertion  plates  smooth  or  nearly 
so,  sharp,  slit  into  teeth,  which  project  outward  on  all  of  the  valves. 

Subfamily  CHITONINJE.  Insertion  plates  finely  pectinated,  blunt- 
edged,  the  teeth  all  projecting  outward. 

Subfamily  ACAXTHOPLEURIN^E.  Insertion  plates  smooth  and 
acute,  or  pectinated  and  obtuse  ;  teeth  of  the  posterior  valve  dis- 
tinctly directed  forward,  not  outward. 

(23) 


24 

Subfamily   ISCHNOCHITONIN^E. 

Ischnoidea  CPR.,  Table  of  Regular  Chitons,  and  DALL,  Proc.  I. 
at.  Mus.  l*si>.  p.  283,  (in 'part;  < Jenera  19-24  excluded).— 
hchruH-hitonnlt  DALL,  '  Blake  '  (iastmp.  p.  4M,  1889. 

I  have  above  given  some  of  the  reasons  which  induce  me  to  con- 
sider this  group  as  a  subfamily  rather  than  a  family.  I  am  wholly 
disposed  to  believe  that  the  subfamily  as  here  constituted,  is  rather 
artificial  ;  and  some  of  the  genera  may  require  consolidation.  The 
relation  existing  between  Cluztopleura  and  Tonicia  especially  calls 
tor  investigation  ;  and  there  are  some  forms  (section  Cyanoplax)  which 
seem  to  bridge  the  gap  between  Chcetopleura  and  Tonicella. 

Synopsis  of  Genera  of  Ischnochitonince. 
Genus  V.  LEPTOPLAX  Cpr. 

Valves  thin,  partly  immersed  in  the  thin  smooth  girdle;  insertion 
plates  acute,  having  jew  slits.  Umbo  of  posterior  valve  median. 

Genus  VI.  SPOXGIOCHITON  Cpr. 

Valves  partly  Immersed.  Insertion  plates  acute;  umbo  of  pos- 
terior valve  median.  Girdle  spongy,  having  chaffy  scales  and  hair- 
lets,  and  produced  forward. 

Genus  VII.  CH^ETOPLEUPvA  Shutthv. 

Valves   exposed;  insertion  plates  smoother  obsoletely   grooved 
:<le;  eaves  solid;  umbo  of  posterior  valve  central  or  anterior. 
Girdle  leathery,  more  or  less  hair//. 

Genus  VIII.  TONICELLA  Cpr. 

Valves  exposed ;  insertion  plates  smooth  or  slightly  grooved  out- 
side; eaves  spongy;  umbo  of  posterior  valve  anterior.  Girdle 
leathery  and  smooth,  without  scales  or  hairs. 

Genus  IX.  SCHIZOPLAX  Dall. 

Valves  exposed,  and  similar  to  those  of  Tonicella  except  that  the 
intermediate  valves  have  ^.median  longitudinal  *M  filled  with  cartil- 
age. Eaves  very  sponyij.  ( iirdle  leathery,  as  in  Tonicella. 


LBFTOPLAX,  25 

Gem.>   X.  CALLOCIIIToN 


Valves  rxp<>srd  :   insertion    plates  cut  into   num<  ill   rising 

from  very  *IHHHJ\J  COVCS,  the  teeth  more  or  les~  /mftressed  at  tin-  out- 

side edges.  Sutural-platet  continuous  acron  the  vr,r>/  nhullmr  m*',/;,/,, 
x/;//(.<.  <;irdle  typically  covered  with  fine  eompaet  diamond  -haped 
scales  :  hut  iii  the  suhgnms  Stereochiton  sparsely  downv,  fV«-«jinMit.Iv 
naked  l»y  erosion. 

Genus  XI,  ISCHNOCHITON  Gray. 

Valves  exposed  ;  insertion  phites  sharp,  smooth  ;  eaves  not 
spongy,  or  rarely  so.  Umbo  of  posterior  valve  varying  from  pos- 
terior to  anterior.  Girdle  covered  with  imbricating  scales. 


Genus  V.  LEPTOPLAX  Carpenter,  1882. 

Leptoplax  CPR.  MS.,  and  Table  of  Regular  Chitons,  1871. — DA  i.i.. 
Proc.  U.  S.  Nat.  Mus.  1882,  p.  286.  Type  C.  codrctatus  Sby. 

Valves  thin,  partly  immersed  in  the  thin,  smooth  girdle.  Inser- 
tion plates  acute,  with  few  slits,  but  regular.  Sinus  scarcely  toothed  ; 
mucro  median.  (Q?r.) 

The  prominent  characters  of  this  genus  are,  (1)  valves  partly 
covered  by  a  thin  extension  of  the  girdle,  (2)  girdle  smooth,  as  in 
Tonicella,  (3)  insertion  plates  long,  with  few  slits.  The  gills  are 
unknown. 

L.  COARCTATUS  Sowerby.     PL  11,  figs.  38,  39. 

Shell  elongated,  very  delicate,  little  elevated,  the  dorsal  ridge 
acute  ;  greenish-ashen  or  reddish-olive.  Valves  of  the  normal  form, 
but  two-thirds  covered  by  a  thin  cuticle  continued  from  the  girdle. 
Exposed  portion  of  the  valves  flask-shaped,  the  jugular  area  smooth, 
subelevated,  having  longitudinal  rows  of  points;  central  areas  and 
end  valves  having  large  pustules,  close  and  somewhat  radiately 
placed,  about  20  on  each  side  in  a  young  specimen,  100  in  an  adult  : 
lateral  areas  scarcely  defined ;  mucro  slightly  behind  the  center, 
rather  elevated.  Interior:  Plates  of  insertion  very  long, 
tinted,  here  and  there  delicately  striated  outside.  Slits  small,  in  the 
posterior  valve  6,  posteriorly  situated;  central  valves  1,  anterior 
valves  4,  having  shallow  grooves  running  up  to  the  cave-.  Sinus 


26  SPONGIOCHITOX. 

moderate,  indented  by  the  sculpture  of  the  outside.     Girdle  very 
thin,  ratlin-  expanded,  smooth.     (Cpr.) 

Length  131,  breadth  71  mill.;  divergence  120°. 

Island  of  Bohol,  Philippines- 

Chiton  eoarctatut  SOWKKHV.  1*.  /.  S.  1841,  p.  62.  —  REEVE,  Conch. 
Icon.,  t.  20,  f.  127.  —  Leptoplax  conrdatus  CPR.  MS.,  and  Lept. 
rubrotinrt'i  (  JpR.  -VX.  <>/hn. 

This  mi.irht  he  regarded  as  an  extremely  -delicate  Katheriua,  but  that 
the  valves  are  thrown  forward  and  the  tail-plate  is  Ischnochitonoid 
rather  than  Mopaloid.  It  differs  from  Fannia  as  Ischnochiton  does 
from  Chiton,  in  the  extreme  thinness  and  general  smoothness  of  the 
sharp  teeth  and  in  the  non-dentition  of  the  sinus.  I  have  seen  no 
other  regular  Chiton  in  which  the  insertion  plates  are  tinted,  the 
head  valve  having  only  four  slits,  and  the  tail  valve  with  so  long  a 
lamina,  unh'ssured,  at  the  anterior  sides.  (Cjpr.) 

Carpenter  at  first  described  this  form  under  the  name  rubrotincta 
but  he  discovered  its  identity  with  C.  coarctatus  by  an  examination 
of  the  type  of  the  latter.  The  sculpture  varies  much  ;  sometimes 
there  are  a  few  large  grains,  sometimes  many  smaller  ones. 

Genus  VI.  SPONGIOCHITON  Carpenter. 

Spongiochiton  CPR.,  Table  of  Regular  Chitons,  1873.  —  DALL, 
Proc.  U.  S.  Nat.  Mus.  1882,  p.  272,  283,  286,  289,  290. 

Valves  partly  immersed  ;  insertion  plates  acute,  Ischnoid  ;  sinus 
large,  smooth  ;  raucro  median,  flat  ;  girdle  spongy,  produced  forward. 


S.  PRODUCTUS  Carpenter,  n.  sp. 

Shell  oval,  the  valves  immersed  two-fifths  of  their  width  ;  exposed 
portion  rubicund,  flat,  the  jugum  arcuate,  paler.  Lateral  areas 
scarcely  defined.  Entire  surface  sculptured  with  prominent  pebbles, 
worn  at  the  jugum.  Mucro  submedian,  flat. 

Interior  :  posterior  valve  with  6,  central  valve  1,  anterior  valve 
5  slits;  teeth  long,  acute,  scarcely  serrate;  sinus  wide,  smooth, 
extremely  deep.  Eaves  narrow,  scarcely  grooved. 

Girdle  produced  in  front,  spongy,  sparsely  covered  with  chaffy 
scales  and  translucent  hairlets. 

Length  25,  breadth  161  mill.  ;  divergence  130°.     (Q>r.) 

New  Zealand  (Mus.  Cum.  no.  50). 


(  ill  TOPLS1  i:  \.  -7 

This  very  peculiar  shell  rescmUes  .Mopalia  Mainvillei  in  mantle 
and  inner.);  and  Nuttallina  in  tin-  l«»n.Lr,  Mnooth  plate.-,  -eparaN  d  l.y 
a  d.-ep,  not  laminated  sinn<.  Tin-  side  slils  how,  and 

deep  instead  of  duplicate  and  angular,  as  in  thai 
rior  plates  are  not  tin-own  forward  nor  waved  as  in  Mopalia.  I^av- 
\i\^  out  of  view  the  anterior  prolongation  of  the  mantle,  which  \»  a 
variable  character  even  anioni:  Mopalia,  it  may  be  regarded  as  a 
partially  covered  Tonicella.  The  slits  are  abnormally  few,  as  in 
Leptoplax.  But  for  the  characters  of  the  tail  plate  I  should  have 
considered  it  intermediate  between  Mopalia  and  Katherina.  (< 

Genus  VII.  CH^TOPLEURA  Shuttleworth,  l*f>3. 

Chcctopleura  SHUTTLW.,  Diagn.  neuer  Moll.  no.  4,  iiber  den  Ban 
der  Chitoniden,  etc.,  in  Bern.  Mittheil.  p.  66,  June,  18~>3  (~  Acan- 
thopleuraGray,  ex  parte). —  Choetopleura  CPR.  MS.  and  DALL,  1'roc. 
U.  S.  Nat.  Mus.  1878,  p.  329,  type  C.  peruviana  Lam. — Acantko- 
pleura,  GRAY,  Guide  Moll.  B.  M.  p.  183. 

Valves  as  in  Ischnochiton  ;  eaves  solid  ;  girdle  leathery,  more  or 
less  hairy  ;  gills  extending  almost  or  entirely  to  the  front  end  of  the 
foot. 

The  present  group  seems  to  me  to  stand  naturally  on  the  confines 
of  the  Ischnochitonoid  series,  having  decided  relations  to  the  true 
Chitons  and  especially  to  Tonicia. 

Carpenter  made  a  subgenus,  Maugerella,  under  Chcetoplcura,  for 
a  Radsioid  Californian  form,  which  I  have  excluded  from  the  genus, 
as  its  affinities  are  with  the  Radsioid  Ischnochitons.  The  following 
able  discussion  of  this  genus  is  from  Carpenter's  MS. : 

Shuttleworth,  in  distinguishing  this  genus  from  Acanthopleura  by 
the  mantle  characters  only,  does  not  seem  to  have  observed  the  co- 
ordinate differences  in  the  hind  valve  and  the  insertion  plates. 
Messrs  Adams  united  to  this  genus  Eudoxochiton  and  Craspedo- 
chiton  which  do  not  belong  to  the  same  section.  Gray,  in  his 
"  Guide,"  p.  183,  ignores  the  genera  of  Shuttleworth,  but  preserves 
the  distinction  between  Chsetopleura  and  Acanthopleura.  Most 
unfortunately,  however,  he  chooses  to  keep  the  name  Acanthopleura 
for  Chsetopleura  of  Shuttleworth  and  Add.,  and  makes  a  fresh  name 
Maugeria  for  the  restricted  Acanthopleura  of  Shuttleworth  and 
Add.  Even  if  Shuttleworth  had  been  unwise  in  his  mode  of 
division,  he  would  have  been  entitled  to  precedence ;  but  fortunately 
he  kept  Acanthopleura  for  the  first  section  of  Guilding's  group, 


28  <   II.V.KTI.Kt    i:  \. 


.Jouni.  v,  p.  28,  represented  by  Chiton  spin  osus  8by,     The 

•  Indian  -pecies  belongini:  to  this  section  (A.  picea)  must   have 
been  familiar  to  him  and  u'iven  ri>e  to   the    "  /<ma    crassa    carnosa" 
of   h;>  diairno>i>.   with    which   <  'iKctoj.leura   does  not  accord.     The 
-•ntcd  l»v  <  '.  peruvianus  1'onns  only  tlie  sixtli    among 
seven  sections  into  which   Guilding  divided  his  genus. 

Bhottleworth  and  Adams  place  the  hairy  chitons,  in  Chsetopleura 

and  those  with  shelly  l>ristle>  in  Acanthopleiira. 

The  distinction  is  obvious  as  between  peruviana  and  picea,  but 
not  so  in  t  lie  cast'  of  many  -pecies  \\lien  the  bristles  are  corneous  but 
With  more  or  len  of  shelly  matter  in  their  substance.  There  are 
also  ma;  |  in  which  the  hairs  are  shortened  and  flattened 

into  chaffy  scales  and  others  in  which  hairs  grow  irregularly  in  the 
midst  of  a  spongy  or  chaffy  mass.  Gray,  moreover,  assigns  "shelly 
t-»  the  peruviana  group  and  "  shelly  spines  or  bristles  "  to 
tin-  picea  jrroup.  Tothefir-t.  however,  are  assigned  thin,  to  the 
second  thick  valves.  Both  are  described  as  having  the  insertion 
plate-  pectinated  ;  but  as  being  "  regular  well  developed  "  in  peru- 
viana, hut  "narrow,  rather  irregular  "  in  picea.  This  last  results 
from  what  seem-  to  me  the  essential  difference.  Acanthopleiira  is 
hunch-hacked  on  the  tail  plate,  with  the  insertion  plates  thrown  for- 
;  and  L'r-'ovcil  outside  ;  while  Chretopleura  has  the  normal  tail 
plate  of  Chiton  and  Ischnochiton  and  agrees  with  the  latter  genus 
in  having  the  insertion  plates  not  pectinated  and  nearly  smooth. 
The  transition  forms  from  the  densely  pilose  peruviana  to  the 
smooth  mantle  of  Tonicella  are  so  gradual  that  the  latter  might 
rank  as  a  subgenus  under  Chsetopleura  were  it  not  that  the  gills  in 
tin-  ircmis  are  represented  as  elongate.  (Cpr.) 

<  'h;etopleura  should  be  compared  with  the  Lophyroid  genus  Ton- 
icia,  which  has  similar  ambient  gills  and  solid  eaves,  and  frequently 
has  th-  t--r  i  h  scarcely  more  pectinated  than  in  the  larger  Chieto- 
plcuras. 

The  genus  consists  of  several  groups  of  species.  (1)  Typical 
;h«-r  large,  and  having  very  delicate  sculpture;  and  (2) 
Group  of  C.gemmea,  having  the  lateral  areas  strongly  raised  and 
coarsely  sculptured,  the  central  areas  also  sculptured. 


(1).    Urniij,   of  C. 

n  \I\N\  Lamarck,     IM.  rj,  ii^.  42-46. 

•  •ssed,  dull   a.-h    colored,  the   girdle   clothed    with 
long,  Stifi*.  crUp  black  hair,  a  fringe  of  which  also  projects  from  each 


'  : 'i .1  i   i:  \. 

suture.      The    valves    MIT    iniiiiitclv    .-culpmred    \vitli    very     minute 
granules  in  lin»->  which    diverge    -li-htly  at    the  jiiiriini,  more    upon 
tin1   >ide-   ol'  the    central    area-,  divaricate   on    tlie    horder    ln-t 
central  and  lateral  areas,  and  an-  radiating  upon    the    liiti-ral    ai 
and  tenninal  valves.      The  iimho  of  the  tail  valve  i>  low,  -omeuhal 
anterior. 

Interior  white  with  a  brown  stain  at  the  back  edire  of  each  valv«-. 
Anterior  valve  having  lon^-  insertion  plates  which  are  di.-tinctlv 
crennlated  outside,  ami  have  !)-!()  slits,  central  valves  with  1  -lit, 
post,  valve  with  7~V  slits.  Sutural  plates  very  broad,  connected 
across  the  sinus  hy  a  narrow  plate;  eaves  narrow,  .-hort, 

Length  38,  breadth  20  mill. 

Lima,  Peru;   Chili;  to  Oij>r 

Chiton  periivianus  LMK.,  An.  s.  Vert,  vi,  p.  321  ;  ed.  Dh.,  vii,  p. 
491. — Barnes,  Amer.  Jour.  Sci.  vii,  p.  10,  t.  3,  f.  2. — SOWB.,  Conch. 
Illustr.  f.  44. —  KI:I:\  i:  Conch.  Icon.  f.  50. —  Chaetopleura  peruviana 
Lm.,  SHUTTLW.,  Diagn.  n.  Moll.  nr.  4,  p.  07.—  \{<><  \\  i.m; .,  Moll. 
Cap  Horn,  p.  1-^). — Acanthopleura  peruviana  Lm.,  TAP.  CAN., 
Viag.  Magenta,  p.  77. 

This  form  is  readily  known  by  its  girdle  covering  and  sutural 
fringes  of  long  black  hairs.  The  sutural  plates  are  strongly  devel- 
oped, slightly  recalling  Leptoplax.  The  hair  is  crisp  and  coarse, 
like  that  of  a  horse's  tail.  The  gills  extend  forward  to  the  head. 

C.  HENNAHI  Gray.     PI.  12,  figs.  47,  48,  49  ;  pi.  17,  fig.  39. 

Shell  oval,  rather  depressed,  dorsal  ridge  obtuse,  side  slopes 
nearly  straight.  Color  variable,  but  generally  either  reddish-brown 
marked  with  red,  or  greenish-white  marked  with  brown ;  surface 
smooth  to  the  naked  eye.  Girdle  leathery,  covered  with  short  hairs, 
which  may  readily  be  rubbed  off. 

The  median  valves  are  about  four  times  as  wide  as  long;  the 
lateral  areas  are  only  weakly  indicated  ;  the  tail  valve  is  depre>-  d, 
with  the  slightly  prominent  umbo  in  front  of  the  middle,  the  pos- 
terior slope  concave.  The  sculpture  consists  of  closely  beaded  ti in- 
separated  threads,  which  are  longitudinal  on  the  central,  radiating 
on  the  lateral  areas  and  end  valves ;  under  this  may  be  seen  an 
excessively  fine,  close  shagreening  of  the  whole  surface. 

Inside  white,  each  valve  marked  with  brown  under  the  beaks. 
Sutural  plates  of  equal  width  from  the  outer  angle  of  the  valve  to  the 
rather  shallow  sinus.  Ant.  valve  having  13,  central  valves  1.  po>t. 


30  CEJSTOPLBURA. 

valve  !•">  >lits,  (i  'arpenter  Liives  :  ant.  v.  10,  centr.  1,  post.  9-12 
slits).  Teeth  sharp,  those  of  the  head  valve  prominently  grooved 
outside.  Eaves  narrow  and  short,  grooved  just  above  the  teeth,  not 
spongy. 

Girdle   .pi.    17,  fig.  39)  granulated,  sparsely  clothed  with  stiff 
white  spinelet-. 

( Jills  continuous  to  the  head,  as  in  C.  pernviana. 

\,  Qgth   13,  l-readth  28  mill. 

Callao  Peru,  on  Pectens,  in  5-7  fms- 

Ch.  henwihi  <JKAY  Spiril.  Zool.  p.  6,  July,  1828. — SOWB.,  Conch. 
Illustr.  t'.  1,  3:>.— RKKVI:.  ( ouch.  Icon.  t.  7,  f.  37,  and  pi.  23,  lower 
mitral  lLrure. 

This  >pecies  is   closely  allied   to    C.   peruviana  in    form   of  the 

valves  and  sculpture.     The  girdle  hairs  are  short,  deciduous,  and 

when    retained    they  are  disposed  to  lie  in  bunches.      The  front 

teeth  are  decidedly  grooved   outside,  in  old  specimens   resembling 

lafulva. 

i. ii  i-   Reeve.     PI.  14,  fig.  80. 

Shell  ovate,  smooth  or  very  closely  marked  throughout  with 
minute  raised  dots  ;  lateral  areas  faintly  radiately  grooved.  Red- 
dish chocolate-brown,  unspotted  ;  ligament  horny,  beset  with  very 
short,  hard  bristles  (Rve.) 

Habitat  unknown. 

f'hHon  »<>!>;iis  "Gray,"  REEVE,  Conch.  Icon.  t.  21,  f.  139,  May, 
1847.  Not  Chiton  nobilis  Gray. —  Chcetopleura  nobilis  Rv.,  CPR. 

m 

Carpenter  further  describes  the  type  specimen:  mucro  median 
little  elevated  :  valves  rounded  at  the  sides.  Interior:  post,  valve 
with  J),  ant.  11,  centr.  1  slit.  Teeth  acute;  eaves  small;  sinus 
small,  deep,  planate,  smooth.  Girdle  leathery,  pale  brown,  sparsely 
and  irre<rular]y  I.CM-I  with  very  short,  solid,  black,  somewhat  scale- 
like  bristles. 

The  above  is  written  from  the  type  specimen  which  Rve.  described 
as  the  C.  nobilis  of  Cray,  and  which  Mr.  Adams  most  kindly  sub- 
mitted to  my  examination.  This  shell  proves  to  be  a  normal  ( 'lueto- 
.i  :  while  Knnoxochiton  nobilis  Gray,  belongs  to  the  Lophy- 
roid  section.  Lest  the  confusion  should  be  repeated,  the  following 
notes  on  the  sculpture  of  C.  nobilis  Rve.  may  be  useful. 


i  1 1. r.i <>r i  i.i  i:  \.  :;i 

(Vntral    area-   having  sul.parallel    or    slightly    radiating    lin- 
granules,  about    L'U  on    cadi    side.      Lateral    area-  -eareely    «|eline<|, 
having  about   1<>  irregular  radiating  line-,  tin-  ant.  va! 
post,    valve   40  such  lines.      Kntiiv  siirlaee  nio-t  niiniitely  pun. 

This  species  must  not  l)e  mistaken  for  the  e.r/crn<i/ii/  verv  -imilar 

Eudozochiton. 

(2)   Group  of  C.  gemmea. 

(  .  I.I:MMI-:A  Carpenter,  n.  sp.     PI.  13,  figs.  69-74. 

Shell  oblong,  elevated,  red,  olive-ashen  or  yellow;  umlm  of  tail 
valve  depressed,  situated  behind  the  middle.  Lateral  areas  decidedly 
raised,  coarsely  radiately  tuberculate;  central  areas  having  longi- 
tudinal beaded  line.  Girdle  narrow,  leathery,  sparsely  clothed  with 
short  hyaline  hairs,  which  are  readily  rubbed  off. 

The  valves  are  elevated.  The  central  areas  are  sculptured  with 
elevated,  distinctly  beaded  longitudinal  cords,  about  15  in  number 
on  each  side ;  they  became  very  small  or  subobsolete  upon  the 
jugum.  The  lateral  areas  are  strongly  differentiated  ;  they  have  5 
to  7  radiating  rows  of  distinct,  clear-cut  tubercles.  The  mucro  does 
not  rise  above  the  general  level  of  the  posterior  valve. 

Inside  often  tinted  with  red,  often  having  a  red  or  black  spot  at 
the  jugal  sinus.  Sutural  plates  well-rounded,  the  sinus  rather  deep 
and  angular.  Anterior  valve  having  9-12,  median  1,  posterior 
valve  7-8  slits.  Teeth  rather  blunt  and  stout ;  eaves  not  spongy, 
rather  wide. 

Length  16?,  breadth  8  mill. 

Monterey,  California. 

Chastopleura  gemmea  CPU.  MS. 

This  beautiful  little  species  is  excessively  similar  to  Ischnochiton 
mertensii  in  sculpture,  but  the  smaller  size,  narrower  form,  and 
especially  the  short,  transparent  hairs  of  the  girdle,  distinguish  it. 

C.  BULLATA  Carpenter. 

Shell  subovate,  elevated,  olivaceous;  intermediate  valves  ornamented 
with  strong  rows  of  pustules ;  lateral  areas  very  narrow,  tubercu- 
late, sometimes  pustulate.  Central  areas  having  lines  of  tubercles, 
about  7  on  each  side,  and  perpendicular  lines,  interstices  granulated. 
End  valves  having  about  11  radiating  rows  of  pustules;  mucro 
somewhat  conspicuous.  Girdle  wide,  having  small  hairlets.  Sutural 


32  OttBIOPLEURA.  , 

plates  triaiiLMilatc  :  sinus  deep;   margins  of  the  valves  simple,  the 
median  having  1,  the  terminal  valves  about  7  slits.  (£)>?'•) 
ill,  :;.  alt.  ,  mill;  divergence  110°. 

if/an,  on  Spondylus  calcil'er. 

Lepidopleurus  bntlaliis  Cri:.,  Ma/at.  Catal.  p.  195.  —  Chtttojil* 
lnll»      '  !/>'.—  L.  hnll'itu*  i'"r.  (•<>/<•  Iferus  CPR.,  1.  c.  p.  196. 

One  fresh  specimen  (><>me\vliat  crushed  in  extraction)  and  a  few 
perfe  i  were  found  of  this  species,  which  is  characterized  by 

the  very  >t  mil-:  row  <>f  tubercles,  (like  pebbles)  which  lie  on  the 
diagonal  line;  by  the  rows  of  somewhat  strong  tubercles  on  the 
central  area,  rmminir  perpendicularly  from  the  diagonal  towards  the 
juguni  and  the  granules  over  the  whole  surface,  somewhat  corru- 
gated on  the  juguni.  The  internal  plates  of  all  the  valves  have  an 
:ial  projection  from  the  outer  surface,  as  in  L.  .«ni<juJuem. 

Carpenter  describes  a  larger  specimen  in  ms.  as  follows  :  Mucro 
median,  -eaively  elevated.  Vermilion  and  olive,  very  irregularly, 
vividly  maculated.  Interior:  posterior  valve  with  9,  central  valves 
1,  anterior  valve  11  slits.  Teeth  acute.  Eaves  projecting,  pectin- 
ated by  the  sculpture.  Sinus  moderate,  high,  laminate.  Girdle 
smooth,  ornamented  with  sparse  hairlets.  Gills  subambient,  scarcely 
reaehiiiLT  the  head.  Abedhas  Reefs.  (Mus.  Yale  College).  This 
specimen  is  about  15  mill,  long,  6i  broad,  divergence  125°.  It 
agrees  in  most  respects  with  the  very  young  shell  described  in  Maz. 
(  'atal.,  but  is  much  longer  in  proportion. 

Yai.  C  \i.<  ii  I.HA  Cpr. 

Lateral  areas  tuberculate,  without  pustules  ;  diagonal  line  peb- 
bled ;  central  areas  with  lines  of  tubercles  irregular,  tubercles  smal- 
ler. Hairs  of  the  girdle  larger,  very  close. 


(  '.  r.i  AMI  <  arpenter. 

Shell  ovate,  elevated,  brown-olive  or  maculated  with  whitish  and 
hlui.-h.  Intermediate  valves  strongly  mucronate,  interstices  curved, 
margins  >omewhat  rounded.  Posterior  valve  depressed,  excavated, 
the  mucro  >mall.  superior;  jugal  and  lateral  areas  indistinct  :  sur- 
with  granules  and  ornamented  with  small  close  points. 
Sutural  plates  large,  curved;  sinus  tlat  :  insertion  plates  acute,  the 
intermediate  valves  with  1,  terminal  valves  l!)  slits.  Girdle  hairy, 
-pines  .-mall,  erect,  tlat. 

•  adth  3i,alt.  1  mill.;  divergence  110°. 

it  Ian, 


(  ii  i  i-.ri.i  i  i:  \. 


.'  l,t'i>i<1»i>l>'iirn.<  l»,inii    <Yi:.,     Ma/.  <'atal.    p.    l'.»7.     -  t  '/m  In/,/. 
bnmii  (  Yi;.  MS. 

Diilcrs    from     L.    Macandrei    in    l.<-in-     longer,   with    lip 
mucronated  and  rounded  at  tin-  extremities,  the  posterior  heini:  hol- 
lowed out  and  the  rot  much  elevated,  without    conspicuous    middle 
portion    or    lateral   areas.      The    only   perfect    specimen    found 
Acma-a  fax-icularis)  displays  no  trace  of  solid  scales.     Tin-  account 
of  the  interior  is  taken    from    :i    lame    central    and    -mall    anterior 
valve  supposed  to  belong  to  this  species  from  their  agreement   in 
other  respects. 

C.  FLAVE8CEN8  Carpenter.      Unfigured. 

Shell  ovate,  much  depressed,  yellow,  spotted  with  orange.  Valves 
wide,  somewhat  rounded  at  the  margins,  the  interstices  curved, 
strongly  mucronate.  Lateral  areas  and  jugum  indistinct  ;  mucro 
small,  superior.  Entire  surface  furnished  with  close  granule-, 
scarcely  punctulate  ;  girdle  thick,  nearly  smooth,  furnished  at  the 
margin  with  delicate  erect  flattened  spines.  Sutural  plates  large, 
arcuate;  sinus  large.  End  valves  with  about  10,  intermediate 
valves  1  slit.  Length  4,  breadth  2|,  alt.  f  mill.;  divergence  150°. 

Mazatlan,  on  shells. 

Chiton  flavescens  CARPENTER,  Maz.  Cat.  p.  198. 

This  is  the  least  uncommon  of  the  small  Chitons,  six  specimens 
having  been  found  of  it.  It  is  distinguished  by  its  yellow  color, 
great  depression  and  small  strong  mantle  margin,  without  covering, 
except  at  the  margin  where  a  fine  row  of  transparent  flattened  hairs 
may  be  seen.  The  smaller  lobe  on  the  margins  of  the  inner  valves 
is  bounded  by  two  rows  of  holes  which  proceed  to  the  jugum.  (Q/r.) 

C.  LITRIDA  Sowerby.     PI.  12,  figs.  53,  54. 

Shell  oblong,  rather  elevated,  ashen  ;  front  valve,  lateral  areas  of 
intermediate  valves  and  posterior  valve  coarsely  granulose  ;  central 
areas  longitudinally  sulcate,  threads  between  the  grooves  granulose. 
Length  30,  breadth  15  mill.  (/%.) 

Sta.  Elena,  W.  Colombia,  on  stones  in  5  fms. 

Chiton  Inridus  Sown.,  P.  Z.  S.  1832,  p.  26  ;  Conch.  Illustr.  f.  20. 
—REEVE,  Conch.  Icon.  f.  85.  —  Chiton  srubrtcidus  SOWB.,  P.  7..  S. 
1832,  p.  28  ;  Conch.  Illustr.  f.  21  .—  RKKVI:,  t,  15,  f.  Sl.—IschnocJiiton 
parallelus  CPR.,  Ann.  and  Mag.  N.  Hist.  (3),  xiii,  p.  314.  —  Isch  no- 
chiton  (f  var.)  prasinatm  CPR.,  /.  c.,  p.  314. 
3 


34  <  ii. i  I'.IM.I  TRA. 

To  this  species  Cnr|>enter  unites  C.  teabrimhus  Sowl).    pi.  \'l. 

•  •I   aii.l  !.«•/, nix'/ufon  }><irallelusCpr.,  afigureof  which,  drawn  from 
a  Carpenteri;  men   from  Cape  St.  Lucas,  is  given  on  pi.  12, 

fig.  50.      It  is  likely  that   C.  columbiensis  should  be  added  to  the 
synonymy,  as  it  presents  no  differential  characters  of  much  value. 

Var.  PARALLEL*  Cpr,     PI.  TJ,  fig.  50. 

The  specimen  In-fore  me  of  the  form  jtarallelus,  measures  17  by 
11  mill.  It  is  rather  acutely  carinated,  the  sides  slopes  nearly 
straight.  There  are  17  beaded  longitudinal  threads  on  each  side 
of  the  central  areas,  and  from  6  to  7  rows  of  separated,  rounded ? 
erect  tubercles  on  each  lateral  area.  The  lateral  areas  are  decid- 
dly  elevated;  the  mucro  is  slightly  prominent.  The  girdle  has 
sparsely  scattered  hyaline  short  hairs.  The  gills  continue  as  far  as 
the  front  end  of  the  foot.  The  outside  is  reddish,  marbled  with 
darker  and  white,  the  girdle  dark  ashen.  The  interior  is  bluish- 
white. 

Cape  St.  Lucas. 

The  >tyle  of  sculpture  is  the  same  as  in  C.  gemmea,  but  the  shell 
is  much  broader  than  in  that  species. 

Var.  r i :. \SINATA  Cpr. 

lihir  to  jHir'i/lefn,  but   vivid  green;    lateral  areas  irregularly 
ornamented  with  series  of  tubercles.     Cape  St.  Lucas. 

Var.  «  "i.i  MI;II  NMS  Sowerby.     PI.  12,  figs.  51,  52. 

Shell  ovate,  a  little  depressed,  ashen  ;  end  valves  and  lateral 
MPBAS --parsely  gnumlote;  Central  areas  longitudinally  <rrunose-lin- 
eate.  (S6y.)  Length  31,  breadth  18 J  mill. 

Bay  of  Panama,  under  stones  at  low  water. 

C.co/»'wiAi>//*MSowi:..  P.  /.S.I  832,  p.  58;  Conch.  Illustr.  f.  15.— 
L'I.I.VI  .  Conch,  leuii.  f.  82. —  Clwtopleura  columbiensis  Sby.  CPR., 
m§. 

Carpenter  says:  Mucro  slightly  in  front  of  the  middle,  sul>- 
planate,  the  posterior  part  exeiirved.  Interior:  posterior  valve 
with  *.  anterior  valve  !),  central  1  >lit.  Teeth  obtuse,  scarcely 
roughened;  eaves  large;  sinus  narrow,  moderately  deep.  Girdle 
leathery,  with  a  f.-w  corneous  hairlets.  .  .  .  One  of  Colonel 
Jewett's  specimens  is  of  a  uniform  dark  chocolate  color,  but  parts 
of  some  ,,f  the  valve-  are  of  a  variegated  olive. 

Of  another  specimen  ( 'pr.  writes:  One  specimen  of  the  wiliri- 
culus  type.  Girdle  finely  hairy.  K'.d.  with  dark  girdle.  On  each 


»  ii  i  POP1  i  i  i:  \. 
of  the    central    RFCM    llieiv   an-   l»i  tinr  row-  of  h»-ads  nnt 

developed  ;  jugular  araai  not  defined  ;  -idr  areai  u  ith  in 

larly  >cattetvd  grains.      Mucro  central,  d«-pi .--( •<!. 

Length  -s,  breadth  17  mill. 

<  'arpenter  seem-  di-po-cd  to  unite  to  Columbian.*;.*  tin-  -pecies 
described  as  ncnhr'n-nlun  and  luritlii*,  the  former  of  these  two  being 
leaB,  the  latter  more  beaded  than  the  typical  fiolumbittufa  In  case 
this  view  is  correct,  columbiensis  will  fall  into  the  synonymy  of 
luridut. 

C.  ISABELLEI  d'Orbigny.     PI.  13,  i\^<.  ">",  58. 

Shell  oblong,  brown  ;  back  carinatcd  ;  front  valve  and  lateral 
areas  of  the  intermediate  valves  radiutel}'  granulate;  central  treat 
longitudinally  granulose-striate.  Length  22  mill.  (Orb.) 

9  Bay  of  San  Bias,  Patay<> 

Chiton  isabellei  ORB.,  Voy.  dans  1'Amer.  Mr  rid.  p.  488,  t.  «;:>,  f. 
14-1!). —  Tonicia  isabellei  ROCHEBR.,  Cap  Horn,  p.  138. —  Chceto- 
pleura  isabellei  CPR.  MS. 

Allied,  by  its  granulated  strife,  to  C.  peruvianus,  but  narrower, 
more  carinated,  the  girdle  smooth.  (  Orb.*) 

The  gills  are  figured  as  continuing  almost  to  the  front  end  of  the 
foot.  In  the  absence  of  any  information  regarding  the  insertion 
plates  it  is  impossible  to  say  whether  this  species  is  a  Tmnriit  or  a 
Ckcetopleura ;  if  the  latter,  the  girdle  is  probably  not  truly  smooth. 
In  sculpture  it  seems  near  to  columbiensis  and  its  allies. 

C.  DIEFFENBACHII  Reeve.     PI.  13,  figs.  65,  66. 

Shell  somewhat  elongately  ovate  ;  valves  covered  with  very  min- 
ute raised  dots;  lateral  areas  scarcely  raised  ;  posterior  valve  umho- 
nated  ;  variegated  with  red,  green  and  yellow ;  ligament  horny, 
arenaceous.  (Rve.) 

Newcastle.  A  u.<tr<dii. 

Chiton  dieffenbachii  Rvi-;.,  Conch.  Icon.  t.  2'J,  f.  14!';  species  no. 
148. 

The  locality  must  be  regarded  with  doubt  until  confirmed.  It 
mav  prove  to  be  from  Peru,  and  a  synonym  or  variety  of  ( '.  Inr'nlt 
Sowb.  The  figure  is  enlarged. 

C.  APICULATA  Say.     PL  13,  figs.  75-79. 
Shell  oval,  elevated,  light  butf  or  aaheo,  unicolored  <>r  having 

black  patches  at  the  sides  or  on  the  ridge  (sometimes  red  or  purple 


36  <  I  LF/TOPLEURA. 

in  Southern  specimens);  carinated,  the  side-slopes  nearly  straight; 
central  areas  having  headed  threads,  lateral  areas  and  end  valves 
havin.ir  numerous  scattered  pustules. 

The  lateral  areas  are  distinctly  defined,  raised,  and  bear  numer- 
ous erect  rounded  pustules,  irregularly  scattered,  not  arranged  in 
rows.  The  end  valves  have  the  same  sculpture,  but  the  pustules 
are  more  crowded.  The  central  areas  have  minutely  beaded  longi- 
tudinal thivads,  f'r«»m  15  to  20  on  each  side.  The  umbo  of  the  pos- 
terior valve  is  in  front  of  the  middle,  and  rendered  slightly  pro- 
jecting by  the  concavity  of  the  slope  back  of  it. 

The  interior  is  white  or  stained  with  leaden  in  places.  The 
sutural  plates  are  rounded  ;  sinus  moderate  but  angular.  Slits  of 
anterior  valve  11,  central  valves  1,  posterior  valve  9-11.  Teeth 
slightly  crenulated  ;  eaves  short,  solid. 

Girdle  narrow,  bearing  sparsely  scattered,  transparent,  short 
bain. 

Gills  extending  almost  to  the  forward  end  of  the  foot,  24  branchiae 
on  each  side. 

Length  17,  breadth  10  mill. 

Length  16,  breadth  12  mill. 

Cape  Cod,  Massachusetts,  to  Florida. 

Chiton  apiculatus  SAY,  Amer.  Conch.,  edit.  Binney,  p.  231. — 
S,,wi:..  Conch.  Illustr.  f.  140.— DsKAY,  Moll.  N.  Y.  p.  164,  t.  10,  f. 
201,  202.— GOULD,  Invert,  of  Mass.  (edit.  Binney),  p.  258,  f.  522. 
—  Chcetopleura  apiculata  Say,  CPR.  Ann.  Mag.  N.  H.  (4),  xiii,  p. 
120.— DALL,  Proc.  U.  S.  Nat.  Mus.  1882,  p.  410  ;  Bull.  37,  U.  S. 
Nat.  Mus.,  p.  172,  t.  51,  f.  10. —  Chiton  labeculatus  KEEVE,  Conch. 
Icon.  t.  18,  f.  108. 

The  tubercles  of  the  lateral  areas  and  end  valves  of  this  species 
show  a  lack  of  arrangement  into  radiating  rows,  which  will  readily 
distinguish  this  from  other  species. 

It  i>  ijuitc  commonly  distributed  along  the  Atlantic  coast  of  the 
Tinted  States  from  Nantucket  to  Florida,  and  has  also  been 
reported  from  Haiti. 

The  North,  in  examples  are  generally  buff  or  ash  colored,  some- 
times  with  patches  of  black;  but  in  a  suite  before  me  from  Marco, 
Florida,  one  specimen  is  scarlet  and  another  purplish-pink.  These 
southern  examples,  whilst  agree inir  with  the  typical  form  in  sculp- 
,  are  smaller  and  comparatively  narrower.  (Figs.  78,  79.) 
A  specimen  from  Angfaeea,  New  Jersey,  baa  the  lateral  areas  and 


<  ii  BTOPLE1  i:  \- 

end  valves  pink,  the  central  areas  Imll'.  :in<l  each  valve  ha.-  a  trian- 
gular black  patch  at  the  dorsal  ridiri-.  The  ^ii-dle  i-  alternately 
hull'  and  pink. 

C.  CANDI8A  TUB  Shuttle  worth,     Unfigured. 

Shell  elliptical,  convex,  dull  waxen,  the  hack  sometimes  handed 
with  white;  terminal  valves  having  large  white  granules,  which  are 
much  elevated,  sparsely  and  somewhat  concentrically  arrai 
Median  valves  subcarinated,  the  central  areas  having  smaller  whit- 
ish granules,  arranged  in  straight  necklace-like  series,  crowding  at 
the  umbones;  lateral  areas  conspicuously  elevated,  having  large, 
remote,  irregularly  placed  granules.  Entire  surface  covered  with  a 
very  minute,  chaffy  puncticulation.  Girdle  narrow,  waxen,  marbled 
with  pale  brown;  chaffy-pustulose,  and  having  pellucid,  corneous 
white  setae  here  and  there,  especially  at  the  insertions  of  the  valves. 

Length  8-9,  breadth  4^-5  mill. 

Guadeloupe,  on  dead  valve  of  Cardium  serratum. 

Chiton  (Chwtopleura)  candisatus  SHUTTL.,  Jour,  de  Conch.  1856, 
p.  168. 

Apparently  closely  resembling  C.  apiculata  Say,  in  pattern  of 
sculpture. 

C.  JANEIRENSIS  Gray.     PI.  13,  figs.  59,  60. 

Shell  oblong,  elevated,  rather  narrow ;  dorsal  ridge  somewhat 
angular,  olive-ashen  or  brownish  ;  strongly  sculptured,  the  mucro 
in  front  of  the  middle,  rather  prominent. 

Lateral  areas  strongly  elevated,  sculptured  with  four  coarse, 
granoseribs;  anterior  valve  having  11  to  18  such  ribs,  usually 
having  a  tendency  to  be  in  pairs  or  to  split.  Central  areas  having 
about  12  granose  acute  threads  on  each  side  of  the  jugum,  parallel 
with  it. 

Interior  white,  sutural  plates  rounded ;  sinus  shallow ;  anterior 
valve  with  10,  median  valves  1,  posterior  valve  9  slits.  Teeth  solid, 
eaves  wide,  solid. 

Girdle  having  a  few  delicate  short  hairs. 

Length  18,  breadth  9  mill. 

Gills  reaching  the  neck. 

Key  West,  Florida,  to  Rio  Janeiro,  Brazil. 

Chiton  janeirensis  GRAY,  Spicil.  Zool.  p.  6,  t.  iii,  f.  8,  1828. — 
SOWB.,  in  Zool.  Beechey's  Voy.,  t.  40,  f.  2. — REEVE,  Conch.  Icon, 


38  CH-KTOPLEURA. 

t.  19,  f.  116  (not  t.  15,  f.  81).— SOWB.  Conch.  Illustr.  f.  56.—  Chcs- 
toplt  irensis  CrR.  MS. ;  C.  apparata  and  Callistochiton  rufi- 

costaim  CPR.,  olim. —  Cluetopleura  janeirensis  DALL,  Bull.  37,  U.  S. 
Nat.  MH-.  ]>.  M'1—i'hitnn  segmentatus  REEVE,  Conch.  Icon.  t.  23, 
.. —  /  'It  if  on  (Chcelopleura)  asper  SHUTTLW.,  Jour,  de  Conchyl. 
1856,  p.  169. 

Tli is  species  is  much  elongated,  about  twice  as  long  as  broad- 
The  sculpture  of  the  end  valves  and  lateral  areas  consists  of  coaix -. 
nodulous  ribs,  which  are  quite  unlike  the  clear-cut  pustules  of  C. 
meet,  etc. 

Young  specimens  have  only  two  or  three  nodulous  ribs  on  the 
lateral  areas. 

The  C.  segmentatus  of  Reeve  (pi.  13,  figs.  61,  62)  differs  in  no 
way  from  the  type. 

C.  SPINULOSA  Gray.    PL  13,  figs.  63,  64. 

Shell  ashen,  partially  tessellated  with  dark  and  light  at  the 
sutures,  and  stained  with  brown  on  some  of  the  jugular  areas. 
Jugum  very  acute,  elevated.  Mucro  median,  not  much  raised,  the 
posterior  slope  very  concave.  Jugal  area  not  distinct;  central 
areas  having  about  22  rows  of  very  fine  granules  on  each  side  of 
the  otherwise  smooth  areas ;  lateral  areas  much  raised,  having 
about  10  rows  of  radiating  grains,  separate,  sparse;  grains  very 
irregular  and  sparse  on  terminal  valves. 

Interior:  Anterior  valve  with  10,  central  valves  1,  posterior 
valve  9  slits.  Teeth  not  very  sharp  but  Ischnoid,  the  posterior 
slightly  niLrulose.  Sinus  smooth,  channelled,  broad,  deep,  the 
cting  jugular  sculpture  of  the  outside  giving  a  faint  appear- 
ance of  denticulation.  Eaves  moderate,  not  spongy.  Interior 
whitish,  with  two  rays  of  chestnut. 

Length  31,  breadth  15*  mill. 

Rio   Janeiro. 

Ch'r  nlosus  GRAY,  Spicil.  Zool.  p.  6,  t.  6,  f.  7,  7a. — Sowb., 

Conch.  111.  f.  84,  84a.— REEVE,  Conch.   Icon.  t.  27,  f.  90.—  Chceto- 
•a  CI-R.,  MS. 

It  is  doubtful  whether  the  C.  spinulom  of  Sowerby,  Reeve  and 
Carpenter  is  the  same  as  the  form  originally  so  named  by  Gray. 
Carpenter's  description,  given  above,  is  drawn  from  a  single  speci- 
men, which  apparently  served  Reeve  for  his  illustration.  This 
specimen  i-  much  injured,  having  lost  its  girdle,  and  some  of  the 


.    1 1.1    K.l'l.l   IRA.  89 

valves   ami    teeth    an-    broken.     Tin-    ii.L'im-s    ln-rr-  -/iven    an-    from 
Reeve. 

C.*8owi-:i:uiANA  Reeve.     PI.  13,  figs.  67,  68. 

Shell  <»hlon.i:-ovatr,  valves  having  the  lateral  areas   (•••ii-pieuously 
elevated,  granoaely  ridged  throughout,  riders  of  tin-  central  areas 
much    tiner.      Dull  yellowish-brown,  with  a  triangular  \vhiti.-h 
along  the  umbonial   summit   of   each    valve.      Ligament   hornv. 
CRw.) 

Rio  Janeiro. 

Chiton  janeirensis  Gray,  REEVE,  Conch.  Icon.  t.  !;">,  f.  80. —  C. 
sowerbianus  REEVE,  /.  c.,  in  note  under  species  No.  116,  May,  1847. 
— Sowerbyi  REEVE,  /.  c.,  expl.  of  pi.,  detail  of  sculpture,  sp.  80. — 
Sower  by  anus  REEVE,  I.  c.,  index  to  Chiton. 

Carpenter  says :  Seems  to  me  a  coarse  var.  of  spinulosa  Gray. 
Rio  Janeiro.  Very  like  apiculata,  but  with  more  swelling  side  areas. 
The  sinus  represented  in  the  sculptured  figure  of  Reeve  is  only  the 
part  left  after  the  swelling  of  the  sides.  With  this  impression,  I 
did  not  think  it  necessary  to  examine  the  single  specimen  in  Cum- 
ing's  collection;  but  on  further  examination  I  thought  it  might  be  a 
distinct  species  and  described  it  thus  :  Valves  arched  ;  jugum  rather 
rounded  ;  jugular  area  finely  striate.  Central  areas  having  about 
18  nearly  parallel  ribs  on  each  side,  the  interstices  decussated 
between  the  ribs,  which  are  sharp  (not  in  necklaces).  Lateral 
areas  swelling,  with  6  to  8  very  close  rows  of  coarse  granules,  inter- 
calating, and  no  spaces  between.  In  the  end  valves  they  go  into 
close  radiating  rows.  Mucro  in  front  of  the  middle,  depressed,  the 
slope  behind  it  very  concave.  Girdle  with  very  few  scattered  hairs. 
Interior:  Anterior  valve  with  9,  central  1,  posterior  8  slits;  teeth 
sharp,  normal ;  eaves  conspicuous,  rugulose,  but  not  spongy.  Sinus 
moderate,  sharp,  deep,  channelled. 

Length  26£,  breadth  133  mill. 

C.  ARMILLATA  Carpenter,  n.  sp.      Unfigured. 

Shell  subelongate,  elevated,  the  jugum  acute;  mucro  a  little  in 
front  of  the  middle;  reddish-brown,  maculated  with  darker. 
Valves  quadrate,  scarcely  apicate;  jugal  area  scarcely  defined; 
central  areas  having  14  to  20  lines  of  small  granules  on  each  side, 
the  interstices  flat.  Lateral  areas  scarcely  elevated,  having  sub- 
radiating,  distant,  sparse  granules;  entire  surface  nearly  smooth, 
very  minutely  punctulate  and  striatulate  under  a  lens.  Interior: 


4U  TONICELLA. 

Posterior  valve  with  9,  anterior  9,  central   1   slit.     Teeth  acute  ; 
eaves  conspicuous  ;  -inns  narrow,  deep,  smooth.      Girdle  leathery, 
minuU'ly  dowpy-ecaled  and  having  occasional  delicate,  corneous 
hair*.       Opr.)     Length  25,  breadth  11  1  mill.;  divergence  100°. 

Is.  Gorriti  (Mus.  Cum.  No.  34). 

One  of  the  specimens  is  light  colored  on  the  jugum  of  each  valve, 
with  a  triangular  spot.     (Q/r.) 


Genus  VIII.  TONICELLA  Carpenter,  1873. 

Tonicella  CPR.,  Bull.  Essex  Inst.  v,  p.  154,  1873,  type  C.  marmo- 
reus  Fabr.—  DAI.I,  IVoc.  U.S.  Nat.  Mus.  1878,  p.  324.—  Tonin.i, 
in  part  of  (iK.vv,  ADAMS,  et  at.  —  Boreochiton,  (part)  SARS,  Moll. 
Reg.  Arct.  N..rv.  p.  116,  1878. 

Valves,  sutural  plates  sinus  and  teeth  as  in  Ischnochiton,  but  the 
•  are  spongy  ;  girdle  as  in  Tonicia,  leathery,  smooth  or  nearly 
so.  Gills  extending  forward  from  two-thirds  to  three-fourths  the 
length  of  the  foot. 

Distribution,  Northern  Atlantic  and  Northern  Pacific  shores. 

This  irrouj)  differs  from  Trachydermon,  Callochiton,  Ischnochiton, 
Ckitniileurn,  etc.,  in  its  naked,  scale-less  girdle  ;  from  Stereochit.m 
in  having  a  single  slit  in  the  median  insertion  plates.  It  differs  from 
T»n  iria,  to  which  genus  the  species  of  Tonicella  were  formerly  referred, 
in  the  non-pectinated  insertion  plates,  spongy  eaves  and  shorter  gills. 

The  surface  of  the  valves  is  smooth,  or  evenly  microscopically 
granulated. 

The  essential  differences  between  Tonicella  and  Chtptopleura  seem 
to  !»«•  bridled  by  several  species  which  are  intermediate  in  charac- 
ters of  gills,  girdle  or  both.  The  former  should  perhaps  rank  as  a 
subgenus  rather  than  a  genus,  as  the  pattern  of  sculpturing  of  the 
valves,  shorter  gills  and  spongy  eaves  are  about  all  there  is  to  sep- 
arate the  two  groups. 

Under  Tonicella,  as  a  subgenus,  I  include  the  peculiar  type  Cyano- 
pro  posed  for  the  reception  of  the  C.  hartwegiiCpr.  The  genus 
will  therefore  be  divided  thus: 

Suhgenus  TONMT:I.I.A  s.  s. 
Teeth  rather  long;  valves  nearly  smooth  ;  gills  shorter  than  the 

Subgenus  CYANOPLAX  Pils. 

(h  stumpy,  bi-  or  tri-loh<-d  ;  valves  granulated;  gills  ambient. 


rONIOBl  11 

TONIOKLUI   <  '\>r. 
T.  M\I:M<>KI:A  Fahrieius.      1M.  10,  fiir-    s    L5, 

Shell    oblong    or    uvul,   I'levah'd.    ratln-r    acntclv    angular;    hull', 


closely  speckled  and  maculated  with  -lark   n-d.  as  in    Tr<ic/«/>l> 

ruhcr.    Surface  denttly,  microscopically  granulated,  but  apparently 

smooth.  Lateral  areas  not  distinct.  Valves  beaked,  \im\tn  «.f  pos- 
terior valve  slightly  prominent,  central. 

Interior  rose  tinted;  anterior  valve  with  8-10,  median  valves  1, 
posterior  valve  8-9  slits.  Sutural  plates  broad,  rounded;  >irms 
deep,  angular. 

(Jirdle  leathery,  nude. 

The  gill  rows  extend  forward  three-quarters  the  length  of  the  foot, 
each  containing  20-25  brand)  in-. 

Length  40,  breadth  24  mill. 

Length  27,  breadth  16  mill. 

North  Atlantic  :  Massachusetts  Bay  to  Greenland;  Holland  to 
Ireland  and  northward.  North  Pacific:  Aleutian  Islands  and 
Japan. 

Chiton  marmoreus  FABR.,  Faun.  Gronl.  p.  420,  1780.  —  FORBES 
&  HANLEY,  Hist.  Brit.  Moll,  ii,  p.  414,  t.  58,  f  .  2  ;  t.  59,  f.  4.— 
JEFFREYS,  Brit.  Conch,  iii,  p.  227  ;  v,  p.  199,  t.  56,  f.  7.  —  Chiton, 
(Tonicia)  marmoreus  Fabr.  Smith,  Ann.  and  Mag.  N.  H.  (4)  xx,  p. 
139  (Franklyn  Pierce  Bay,  Greenland).  —  Tonicella  marmorea  Fabr. 
CPR.,  Bull.  Essex  Inst.  v,  p.  154,  1873  ;  Ann.  Mag.  N.  Hist.  (4) 
xiii,  p.  121.—  BALL,  I  c.,  vi,  p.  124  (anat.)  ;  Proc.  U.  S.  Nat.  Mus. 
1878,  p.  324.—  Chiton  ruber  SPENGLER,  Skrift.  Nat.  Selsk.  iv,  p.  92, 
not  of  Linne.  —  Chiton  hvvigatus  FLEMING,  Edinb.  Encyc.  p.  113,  t. 
vii  ;  Brit.  Anim.  p.  290.—  REEVE,  Conch.  Icon.  t.  27,  f.  179.  —  / 
Chiton  punctatus  STROM,  (teste  JEFFR.)  Acta  Nidr.  iii,  p.  433,  t.  6, 
f.  14.—  Chiton  latus  LOWE,  Zool.  Journ.  ii,  p.  103,  t.  5,  f.  6,  7.— 
SOWB.,  Conchol.  Illustr.  f.  113.  —  Chiton  fulminatus  COUTH.,  Bost. 
Journ.  Nat.  Hist,  ii,  p.  80,  t.  3,  f.  19.  —  GOULD,  Invert.  Mass,  i,  p. 
14*,  f.  3.  —  Chiton  pictus  BEAN,  in  Thorpe's  Brit.  Mar.  Conch,  p. 
264.  —  Chiton  flemingius  LEACH,  Moll.  (Jt.  Brit.  p.  230.  —  Boreo- 
ch'doH  marmoreus  Fabr.  SARS,  Moll.  Reg.  Arct.  Norv.  p.  116,  t.  8, 
f.  3. 

This  species  has  very  much  the  color  pattern  of  C.  ruber,  Imt 
may  readily  be  distinguished  by  its  nude,  leathery  girdle.  Sars 
was  evidently  led  by  this  superficial  resemblance  to  create  his  genus 


•IL'  TONICELI  A. 

Boreochiton  for  the  two  forms.  The  Greenland  and  East  American 
s|M<im.n>  arc  more  elevated  and  generally  larger  than  the  British 
form,  which  might  retain  the  varietal  name  latus  Lowe. 

Middendorff  found  the  number  of  slits  variable  in  his  specimens 
fn>m  the  White  Sea  and  the  Arctic  coast  of  Russian  Lapland,  the 
anterior  valve  having  5  to  7,  posterior  valve  6  to  9  slits. 

T.  SUBMARMOREA  Middendorff.     PI.  10,  figs.  16-24. 

Shell  oval,  rather  depressed,  rather  smooth  and  shining,  the  entire 

sui  face  seen  under  a  lens  to  be  very  minutely,  regularly  and  closely 

•//•/».      Lateral  areas  scarcely  distinct,  slightly  swollen.     Color 

rosy  or  yellowish-white,  closely  painted  with  spots  and  flames  of  red. 

Interior  rose  colored  ;  terminal  valves  each  with  five  slits. 

<  iirdle  smooth,  shining,  yellow  or  brown. 

Uranchia'  median,  consisting  of  about  24  plumes. 

Length  38,  breadth  24,  alt.  12-13  mill. 

Japan,  Okhotsk  Sea ;  Aleutian  Is.  to  Sitka  and  Fuca  Strait. 

C.  submarmoreus  MIDD.,  Bull.  Acad.  Sci.  St.  Petersb.  iv,  1846  ; 

Mai.  Ross,  i,  p.  98  ;  Sib.  Reise.  p.  178,  t.  14,  f.  7-10  ;  t.  15,  f.  7,  8. 

—  Tonlrcll'i  xnbmarmorea  Midd.,  DALL,  Proc.  U.  S.  Nat.  Mus.  1878, 

p.  296,  t.  I,  f.  7  ;  p.  327  ;  I.  c.  1886,  p.  210.—  Chiton  insignis  REKVK, 

Conch.  Icon.  t.  22?  f.  148,  1847. 

This  species  is  readily  distinguished  from  T.  lineata  by  its  micro- 
scopic granulation  ;  from  T.  marmorea  by  its  more  depressed  shell, 
different  color-pattern,  etc. 

T.  MM: A  i  A  Wood.     PI.  11,  figs.  25-28. 

Shell  oblong,  rather  low,  roundly  arched  or  subcarinated.  Sur- 
face smooth,  shining,  ground  color  light  reddish.  End  valves  con- 
centrically marked  with  black-brown  lines  bordered  above  with 
white,  intermediate  valves  having  similarly  colored  longitudi- 
nal lines,  sloping  obliquely  backward,  the  ridge  or  jugum  of  each 
valv.  havinir  a  light  triangle  with  a  narrower  dark  one  in  the  mid- 
dl«-  on  some  valves.  Occasionally  some  valves  are  wholly  dark 
brown,  unmarked. 

Lateral  areas  scarcely  raised  ;  umbo  of  posterior  valve  in  front 
of  the  middle. 

Interior  white,  more  or  less  tinged  with  rose  color.  Sutnral 
plates  broad,  rounded  ;  sinus  deep  and  angular.  Anterior  valve 
with  8-10,  median  1,  posterior  valve  8-10  slits.  Teeth  short,  espe- 


TONH  i;u.\.  43 

cially  in  the  p(»terior  valve,  and  blunt,  in    adult-    dceidedly    cn-ini- 
lated  at  the  tips  and  obsoletely  fissured  ouf.-ide.       I  :i:ill. 

(Jirdk'  leathery,    apparently    smooth    and    nude,    brown    in    dried 

specimens. 

Gills  extending  forward  two-thirds  the,  length  of  the  foot,  com- 
posed of  27  branch  ire  cadi. 

Length  :>7,  breadth  20  mill. 

Length  30,  breadth  15  mill. ;  divergence  120°. 

From  Bering  Strait  southwestward  to  the  Okhotsk  Sea  and  Japan, 
southeastward  to  the  Bay  of  Monterey,  California.  Aleutian  Is. 

Chiton  lineatus  WOOD,  General  Conchology  p.  15,  t.  2,  f.    1 
1815— MIDD.,  Mai.  Ross,  i,  p.  109,  t.  12,  f.  8,  9.— SOWB.,  Conch.  111. 
f.  77.— RKEVE,  Conch.  Icon.  t.  7,  f.  33.—  Tonicia  lineata  Wood,  H. 
&  A.  AD.,  Genera  Rec.  Moll,  i,  p.  474. —  Tonicella  lineata  CPR.  MS., 
p.  38.— DALL,  Proc.  U.  S.  Nat.  Mus.  1878,  p.  326. 

In  many  old  specimens  of  this  species  the  teeth  are  distinctly, 
though  obsoletely  crenulated  and  striated  outside,  presenting  an 
approach  to  Tonicia..  The  slit  in  the  median  valves  frequently  has 
its  edges  thickened,  and  there  is  a  distinct  notch  on  each  side  of  it. 

This  is  one  of  the  handsomest  north  Pacific  Chitons.  It  is  read- 
ily distinguished  from  T.  marmorea  and  T.  submarmorea  by  the 
absence  of  microscopic  granulation  of  the  surface,  as  well  as  by  the 
pattern  of  coloring.  Dall  writes : 

The  painting  of  this  very  characteristic  species  is  very  variable, 
even  on  different  valves  of  the  same  individual.  Nothing  can 
appear  more  distinct  than  the  coloration  of  typical  specimens  of 
some  varieties,  but  in  a  large  series  the  differences  do  not  hold 
equally  good.  The  number  of  slits  is  also  somewhat  variable,  occa- 
sional abnormal  or  injured  specimens  having  only  six  or  seven  slits 
in  the  tail  valve.  But  fine  and  normal  specimens  of  both  varieties 
show  no  more  than  individual  variations. 

Middendorff,  while  pointing  out  the  distinctions  between  the  fol- 
lowing species  and  T.  marmorea,  appears  to  have  overlooked  the 
connection  between  the  former  and  T.  lineata  and  his  description 
does  not  always  agree  with  his  figures. 

From  Tonicia  lineolata  Sowerby,  from  South  America,  besides  the 
internal  generic  characters,  the  exterior  differs  by  the  absence  of 
punctures  and  raised  granules  at  the  sides. 


44  TONICELI-A. 

T.  SACCH A  i :  i  N  A  I  )al  1 .     Unfigured. 

Shell  small,  oblong,  the  entire  surface  painted  with  lustrous  red 
and  whitish.  Urabo  subcentral,  inconspicuous.  Lateral  areas 
indistinctly  raiaed ;  dorsal  area  blood  colored,  reticulated  in  quin- 
cunx. Anterior  valve  having  10-11,  posterior  8-10,  median  1 
slit.  Teeth  small,  spongy  ;  sinus  small ;  eaves  spongy,  moderate, 
(•irdle  leathery,  (iills  median.  Length  6£,  breadth  4  mill. 

i  ami  Shumagin  Is.;    Kyskn,    Utialashka,  and  Koniu*hi, 
8  fa&,  on  stones;  St.  Paul,  Pribiloff  Is.,  15  fms. 

i  it-ell n  miccharina  DALL,  Proc.  U.  S.  Nat.  Mus.  1878,  pp.  2, 
827. 

This  interesting  little  species  has  the  luster  of  rock-candy,  through 
which  the  microscopic  reticulation  is  barely  perceptible.  It  is 
marked  in  all  the  specimens  obtained,  by  the  red  wine  colored  dor- 
sal areas  contrasted  with  a  waxy  white  color  of  the  lateral  areas, 
rendering  its  recognition  easy.  The  girdle  is  dark,  leathery,  nar- 
row, slightly  pubescent,  and  furnished  at  its  extreme  margin  with  a 
fringe  of  fine  spiny  hairs  or  spicules,  as  in  T.  marmorea. 

T.  SITKKNSIS  Middendorff.     PL  11,  figs.  29,  30,  31. 

Shell  depressed,  smooth,  the  lateral  areas  indistinct,  under  a  lens 
seen  to  be  sparsely  granulose  ;  reddish.  Anterior  valve  having  8, 
1". -tenor  10,  central  1  slit.  Gills  posterior. 

Length  10,  width  6  mill. ;  divergence  130°. 

Sitka. 

C.  sitketms  MIDD.,  Bull.  Acad.  Sci.  St.  Petersb.  vi,  p.  121,  1846  ; 
Mai.  Ross,  i,  p.  112,  t.  13,  f.  1,  2.— Not  C.  sitkensis  Keeve,  1847. 

I  >•  scribed  from  a  single  specimen,  and  not  found  by  later  collec- 
Middendorff  's  figures  and  description  do  not  agree  upon  sev- 
t-ral   points.     The  anterior  teeth  are  figured  as  grooved  outside,  a 
character  also  seen  in  T.  lineata. 

Subgenus  CYANOPLAX  Pilsbry,  1892. 

Valves  resembling  those  of  Ischnochiton,  but  having  the  teeth 
MMiit.  obtuse,  crenulated  or  hi-  or  trilobed  at  their  tips;  and  the 
•  •:!'.•  —  [">i,j\ -.  (iirdle  leathery,  miniftely  papilloBC.  (Jills  extend- 
ing to  the  anterior  end  of  the  foot. 

I)it}!-r>  from  ( '/mtojtfeura  in  the  spongy  eaves  and  papillose,  not 
Jfiini  Lrir<llc;  from  ToniceUa  in  the  long  gills,  different  girdle, 
stumpy,  bilobed  anterior  teeth,  etc.  It  might  be  considered  a 


K.NK  i  i  i.\. 

were   it    n«.(    for    tin-    peculiar    Uunt    tei-th,  ainl.i.-nt 
.irills  and  almost  scalelcss  uinll.-. 

The  girdle  seems  t<»  he  dusted  with  a  few  small,  .-nmot.il  white 

scales  in  places. 

On  account  of  the  spongy  caves   and    hairless   irinllc,  I    include 
this  submenus  in    Tnnlcella  rather  than    in    ( 'Inrtopleura ;    In- 
close all'mitics  with   l)oth   of  these  groups   renders   the  question  of 

its  position  peculiarly  dillicult. 

T.  H.\I:TWI-:<;II  (1arpenter.     PI.  14,  figs.  81,  82,  83,  84,  85. 

Shell  oval,  rather  low,  the  dorsal  ridge  obtusely  rounded ;  dull 
olive  green,  generally  having  a  pair  of  lighter  stripes  on  the  rid^e 
of  each   valve  with  a  black  blotch  outside   of  the   light   dashes. 
Girdle    (fig.    82)    rather    narrow,   dense,   microscopically   cl" 
granulated. 

The  tail  valve  is  convex  as  a  whole,  but  the  subcentral  umbo  is 
not  conspicuous.  The  entire  surface  is  very  closely  microscopically 
granulated,  and  bears  larger  wart-like  granules  irregularly  scattered 
over  the  minute  sculpture,  these  warts  being  much  more  numerous 
upon  the  lateral  areas  (which  are  otherwise  rather  ill-defined)  and 
the  terminal  valves. 

The  interior  is  of  an  intense  blue-green  color.  Sutural  plates 
rounded,  leaving  a  wide,  angular  sinus.  Insertion  plates  shorter 
than  the  eaves,  blunt,  the  anterior  valve  having  the  teeth  bi-  or  tri- 
lobed,  the  posterior  valve  having  them  crenulated.  Slits  of  ante- 
rior valve  10-11  ;  median  valves  1 ;  posterior  valves  9-12.  Eaves 
spongy. 

Gills  extending  forward  to  the  front  end  of  the  foot. 

Length  30,  breadth  17  mill. 

Length  27,  breadth  18  mill. 

Vancouver  Island  to  Magdalena  Bay,  Loiver  California* 

Cliiton  hartwegii  CPR.  P.  Z.  S.  1855,  p.  231  ;  Trachydermon  liart- 
wegii  CPR.  B.  A.  Rep.  1863,  p.  649. —  Chcetopleura  hartwegii  CPR. 
IMS.  p.  45.— DALL,  Proc.  U.  S.  Nat.  Mus.  1878,  p.  329. 

The  prominent  differential  characters  of  this  species  are  its  sys- 
tem of  sculpture,  vivid  blue-green  interior,  slightly  spongy  ea\vs 
stumpy,  bilobed  teeth  of  the  front  valve,  etc. 


46  8CHIZOPLAX. 

Yar.  M   ITAU.II  Cjir. 

Umbo  flatter;  valves  broad,  non-swelling,  squared  at  the  sides, 
and  not  beaked  or  waved.  Posterior  valve  having  11,  central  1, 
anterior  8  slits. 

Habitat  same  as  hartivegii. 

Chiton    uutt'illii  CPR.   P.  Z.   S.  1855,  p.  231 ;   Trachydermon  n., 
(  !•!:.  Suppl.  Rep.  B.  Asso.  1863,  p.  649 ;   CfioBtopleura  n.,  CPR.  MS., 
in  Dall,  Proc.  U.  S.  Nat.  Mus.  1878,  p.  330. 
I  am  unable  to  separate  this  form  from  hartwegii,  as  transition 
linens  are  numerous. 

T.  I.IPUNCTATA  Sowerby.     PL  14,  fig.  90. 

Shell  ovate,  smooth ;  green,  variegated  with  black  and  white ; 
margin  concolored,  generally  having  a  white  spot  on  each  side 
between  the  first  and  second  valves,  marginal  ligament  smooth. 
I.«  ngth  12£,  breadth  6}  mill.  (Sowb.~) 

Liner  Lobos  Island,  Peru,  under  stones  at  low  water. 

C.  bipundatus  SOWB.  P.  Z.  S.  1832,  p.  104;  Conch,  lllustr.  f.  27. 

This  species  varies  much  in  coloring,  some  specimens  being  nearly 
Mark,  others  light  green,  and  some  much  and  prettily  varied.  In 
almost  all  a  white  mark  may  be  observed  on  the  margin  just 
behind  the  anterior  valve.  (Sowb.) 

Carpenter's  notes  on  the  types  areas  follows:  Posterior  valve 
having  9,  central  1,  anterior  valve  9  slits;  teeth  smooth,  stumpy ; 
eaves  very  short,  spongy.  Girdle  smooth  with  extremely  short, 
•  re<l  hairs,  and  two  white  spots  at  the  sutures  of  anterior  valve. 
Valves  beaked,  but  they  seem  to  have  no  pattern  of  sculpture,  only 
a  very  close  quincunx  (arrangement  of  granules).  Looks  like 
a  Tr>t<-l,>j<Jermon  without  scales.  The  mucro  is  in  front  of  the 
middle,  the  slope  behind  it  concave.  Color  greenish,  generally 
with  u  white  blotch  behind. 

Length  12,  breadth  7  mill. 

Congeneric  with  and  very  like  a  small  nuttaUii. 

<  -mis  IX.   SCHIZOPLAX  Dall,  1878. 

Schizoplax  DALL,  Proc.  U.  S.  Nat.  Mus.  p.  2,  Jan.,  1878  ;  1.  c.  p. 
328.— ( !p&  M.S.  Type  Chiton  brandtii  Midd. 

Shell  and  girdle  as  in  Tonicella,  except  that  the  median  valves 
have  a  central  jugal  slit  filled  with  cartilage,  narrower  in  front; 


BCBIZOFLAZ,  17 

very  spongy  ;  gills  extending   three-fourthl    tin- 


of  the  loot. 

This  form,  whilst  allied  to  Tonicelta,  differs  from  all  other  kn 
Chitons  in  the  curious  slit  along  the  jugum  of  each  of  the  median 
valves.  This  slit  is  wedge-shaped,  narrowing  to  a  point  in  front, 
where  it  is  lost  in  the  spongy  jugal  sinus.  The  slit  is  filled  with  a 
cartilaginous  substance  resembling  the  ligament  of  a  bivalve.  Out- 
side there  is  a  corresponding  furrow  not  extending  to  the  terminal 
valves. 

The  tegmentum,  or  external  layer  of  shell  substance,  is  remark- 
ably porous  where  exposed  at  jugal  sinus  and  eaves. 

S.  BRANDTII  Middendorff.     PI.  11,  figs.  32-37. 

Shell  oval,  rather  elevated,  the  jugum  rounded;  olive-brown, 
streaked,  maculated  or  clouded  with  blue,  sometimes  chestnut. 
Umbo  central,  irregularly  planate.  Lateral  areas  scarcely  defined. 
Entire  surface  smooth,  seen  under  a  lens  to  be  finely  granulated  in 
quincunx.  Girdle  narrow,  olive-ashen,  maculated,  closely  beset  with 
minute  spines,  but  appearing  almost  smooth  to  the  naked  eye.  The 
median  valves  have  a  sharply  cut  longitudinal  median  sulcus.  The 
jugal  sinus  is  moderate,  deep,  scarcely  laminate,  conspicuously 
spongy.  Eaves  small,  very  spongy.  Anterior  valve  with  11,  pos- 
terior.ll  and  median  valves  with  1  slit.  Gills  about  22,  subambient. 

Length  16,  width  5  mill.;  divergence  140°. 

Shatttar  Bay,  Okhotsk  Sea;  Aleutian  Is.  eastward  to  Sltka  Har- 
bor, low  water  to  12  fms.,  on  stones  and  shells. 

C.  brandtii  MIDD.,  Bull.  Acad.  Sci.  St.  Petersb.,  vi,  p.  117,  1846  ; 
Mai.  Ross,  i,  p.  128  :  Siber.  Reis.  p.  174,  t.  15,  f.  1-6.—  Schizoplax 
brandti  CPU.  MS.—  DALL,  Proc.  U.  S.  Nat.  Mus.  1878,  pp.  2,  328. 

This  very  remarkable  species  is  very  prettily  marbled  with  olive, 
chestnut  and  blue  ;  the  girdle  generally  dark  olive,  dashed  with 
ashy  spots  and  in  fine  specimens  having  a  pubescent  appearance. 
The  slit  is  occupied  by  a  cartilaginous  substance  of  a  dark  brown 
color,  most  visible  from  within.  It  is  quite  possible  that  it  may 
reach  as  far  south  as  Puget  Sound. 

The  soft  parts  are  yellowish-white.  The  gill  rows  extend  three- 
fourths  of  the  length  of  the  foot  forward  from  their  posterior  termina- 
tion, and  each  contains  about  twenty-two  branchia?.  Mantle-edge 
thick,  plain  ;  veil  small,  plain.  Muzzle  small,  plain,  with  two  large 
squarish  lappets  at  the  posterior  corners.  The  supposed  oviducts 


48  CALLOCHITON. 

open  on  each  side  through  a  small  rounded  papilla  in  the  vicinity 
of  the  third  or  fourth  bronchia,  counting  forward,  and  between  the 
liiu •  of  the  gill  row  and  the  side  of  the  foot.  (Da//.) 

Genus  X.    CALLOCHITON  Gray,  1847. 

.  KAY,  P.  Z.  S.  1847,  pp.  126,  168 ;  type  Ch.  Icevis.— 
Snrrri.KW  Bern.  Mittheil.,  Jimi,  1853,  p.  65. —  Callochiton  GRAY, 
<  iuide  Syst.  Dist.  Moll.  B.  M.  p.  181,  1856.— Callochiton  CAEPKN- 
1 1  i:  .!/>'  1*71,  and  of  DALL,  Proc.  U.  S.  Nat.  Mus.  1882,  p.  286, 
not  Cnllochiton  of  Carpenter's  earlier  writings  (P.  Z.  B.  1865,  p. 
276,  etc.),  —  Callistochitnii. 

Valves  exposed  ;  insertion  plates  rising  out  of  porous  or  spongy 
—  and  cut  into  numerous  teeth;  sutural  plates  connected  or 
continuous  across  the  shallow  jugal  sinus. 

Two  subgenera  are  recognized  by  Carpenter: 

Subgenus  CALLOCHITON  (restricted). 

<  iirdle  covered  with  a  smooth,  compact  layer  of  very  small  dia- 
mond-shaped scales.  • 

Subgenus  STEREOCHITON  Cpr. 

( iirdle  leathery,  more  or  less  downy,  frequently  naked  when  the 
delicate  scales  are  rubbed  off. 


Subgenus  CALLOCHITON  s.  sir. 

The  essential  characters  of  the  restricted  genus  Callochiton  are 
correctly  stated  by  Carpenter  as  follows:  (1)  The  insertion  plates 
are  broken  up  into  very  numerous  teeth  rising  out  of  spongy  eaves ; 
(2)  that  these  have  a  tendency  to  become  propped  outside ;  (3)  that 
the  sinus  is  a  mere  wave  in  the  otherwise  united  branches  of  the 
sutural  lamina ;  (4)  that  the  mantle  is  reticulated  with  what  look 
like  diamond-shaped  scales,  which  are  only  the  points  of  long,  flat- 
tened, closely  appressed  corneous  bodies,  not  found  on  any  other 
Chiton.  For  Gray's  second  group,  in  which  the  peculiar  covering 
is  not  seen,  a  subgenus  should  be  created,  unless  indeed  the  species 
may  rank  under  Trachyradsia.  For  two  species  with  a  mantle 
intermediate  between  (  1m  topleura  and  Tonicella  I  have  establi.-hed 
a  subgenus  Stereochiton.  Of  the  whole  series  there  are  very  few 
species  known.  All  of  them  are  rare  and  display  very  little  sculp- 
ture on  the  val\.  ~. 


(    ALL. HIM  l<>\.  H» 

C,  i    BVIS  Montagu.      I'l.  !»  figs.  !»:>-<)9. 

Shell  oblong,  rather  elevated  and  rather  acutely  earin;i(ed.  tin- 
Bides  Straight  Or  convex.  Color  very  variable,  but  niainlv  vellow- 
ish-olive,  spotted  and  marbled  more  or  less  with  dark  rod  «»r  n-ddi.-li, 
but  green  often  predominating.  Girdle  olive  with  creamy  spot-, 
and  often  red  patches. 

The  valves  are  slightly  beaked  and  apparently  smooth,  but  under 
a  lens  a  fine  but  half-effaced  granulation  is  seen.  The  lateral  areai 
are  distinctly  raised.  The  umbo  is  low  and  in  front  of  the  center. 

Interior  pink-tinted.  Anterior  insertion  plate  having  14  to  17 
slits,  median  valves  with  about  3  slits,  posterior  valve  with  14-K> 
slits.  The  teeth  rise  from  very  spongy  eaves,  and  are  more  or  less 
thickened  at  the  sides  or  "propped."  Sutural  plates  continuous, 
the  jugal  sinus  indicated  by  a  shallow  depression. 

Girdle  firm,  smooth  and  wide,  composed  of  excessively  fine  dia- 
mond-shaped scales. 

Length  21,  breadth  11  mill.,  sometimes  larger. 

British  Seas;  Mediterranean. 

Chiton  l(cvis  MONTAGU,  Test.  Brit.  p.  2. — REEVE,  Conch.  Icon, 
f.  125.— FORBES  &  HANLEY,  Hist.  Brit.  Moll.  p.  411,  t.  58,  f.  3.— 
JEFFREYS,  Brit.  Conch,  iii,  226,  t.  56,  f.  6. —  Chiton  marginatus  of 
some  authors. —  C.  achatinus  BROWN,  Illustr.  Conch.  Gt.  Brit.  p.  65, 
t.  21,  f.  4,  12,  13,  15. —  C.  septemvalvis  MONT.,  Test.  Brit.  p.  3  and 
C.  discprs  MATON  &  RACKETT,  Trans.  Linn.  Soc.  viii,  p.  20. —  Chi- 
on  cranchianus  LEACH,  Moll.  G.  B.  p.  230. — Lepidopleurus  punctu- 
latus  LEACH,  1.  c.  p.  228. —  Chiton  dorice  CAPELLINI,  Journ.  de 
Conchyl.  (2),  iii,  p.  325,  t.  12,  f.  2,  a",  b",  c",  1859. 

This  is  a  rather  high  and  sharply  keeled  species  although 
depressed  specimens  occur.  It  may  be  known  from  other  Euro- 
pean Chitons  by  the  comparative  smoothness  of  both  valves  and 
girdle,  the  latter  wide  and  covered  with  very  fine  diamond-shaped 
scales ;  by  the  propped  teeth  and  spongy  eaves,  the  number  of 
slits  in  the  median  valves,  etc. 

The  Mediterranean  form  has  been  called  C.  dorice,  but  I  am 
unable  to  see  that  it  has  distinctive  characters. 

C.  PLATESSA  Gould.     PI.  10,  figs.  1-5. 

Shell  smooth,  entire  surface  delicately  shagreened,  terminal  valves 
and  lateral  areas  only  with  indistinct  concentric  lines  of  growth  ; 
4 


50  CALLOCHITON. 

lateral  areas  not  prominent,  with  no  radial  markings;  umbones 
small,  pointed. 

Girdle. — With  delicate  flat  elongated  scales. 

Gills. — Extend  along  whole  length  of  foot,  about  thirty  in  num- 
ber on  each  side. 

Color. — Central  areas  yellowish,  obscurely  mottled  with  orange  ; 
on  some  valves  there  are  a  central  and  a  lateral  pair  of  pale  lines. 
Lateral  areas  and  terminal  valves  of  a  uniform  dull  orange  color, 
and  uniformly  spotted  with  minute  black  dots,  which  are  absent 
from  the  central  areas,  the  posterior  border  of  the  valves  is  orna- 
nirntrd  with  alternate  lighter  and  darker  spots.  Ligament  brown- 
ish, with  a  few  irregular  small  white  flecks  and  five  large  white 
spots,  four  very  large  spots  extending  from  the  points  of  junction 
of  the  first  and  second  and  seventh  and  eighth  valves  respectively 
t<»  the  edge  of  the  girdle;  the  fifth  spot  being  in  the  median  line 
N'riorly.  (Haddon.) 

Interior.  Posterior  valve  with  14,  anterior  16  and  median  valves 
with  :!  slits.  Teeth  solid,  separated,  propped  outside,  bifid  or 
aped.  Eaves  very  spongy,  simple,  short.  Sinus  small,  wide  ; 
sutural  plates  united;  girdle  normal.  (Qor.) 

Sydney;  Port  Jackson;  Botany  Bay ;  Australia;  (and  New  Zea- 
land?). 

C.platessa  GLD.,  Proc.  Bost.  Soc.  N.  H.  ii,  1846,  p.  143;  U.  S. 
ExpL  Kxped.  p.  :;L>O;  atlas,  f.  434,  434a,  left  hand,  under  Ch.  fru- 
ticosus. —  I.rjtiiluji/enru  plntessa  GLD.,  Otia  Conch,  p.  242. —  Callo- 
chiton  platessa  Old.,  CPR.,  tnss. — HADDON,  Challenger  Rep.  p.  1 5.— 
'  'It  if  on  i-winns  Rve.,  Conch.  Icon.  t.  22,  f.  14(5,  1*47.— Chiton  ver- 
sicolor  A.  AD.,  I'.  /.  6,  \*~>'2,  p.  !)2,  t.  1(>,  f.  ~).—Leptochiton  versico- 
lor,  ANCIAS,  P.  Z.  S.  1867,  p.  223. 

There  is  an  error  in  the  lettering  of  Gould's  plate,  the  figures 
iM-inir  niimlx-red  4:54  instead  of  431.  There  is  considerable  varia- 
tion in  coloring.  C.  versicolor,  which  Carpenter  considered  a  syn- 
onym, is  represented  in  pi.  10,  fig.  6.  C.  crocinus  (pi.  10,  fig.  7)  is 
a  larger  form,  length  .V>  mill.,  said  to  be  from  New  Zealand. 

C.  PRINCEPS  Carpenter,  n.  sp. 

Shell  large,  very  flat,  oval ;  JIILMIIM  annulate  ;  red,  streaked  with 
paler  and  deeper.  Posterior  valve  large,  very  flat,  the  median 
umbo  inconspicuous.  Lateral  areas  hardly  defined;  central  valves 


OALLOCHIT"  .'-1 

rounded   at   the  mai-iiins,   sometime-   (abnormally?)     p«-«-t  mated. 

Knlhv  surface  roii-pirimiisly  hut   minutely  'jTaimlat.'d. 

Interim-:    Posterior  valve  having  1  7,  anterior    I  *,  median    va 
.">  slits.     Teeth  elegantly  radiately  propped,  curve*!  outwunl,  tv 
three    lobed,   sometimes  striated.       Kaves    short,    reddish,    sp<.nirv. 
Inside    Iiurht     fle<h    colored.       Sutural    plate-     joined,    hroadly    hut 

slightly  sinuated  in  the  middle.    Girdle  normal.    (Cpr.)    Length 
hrcadth  '20  mill.;  divergence  135°. 

Habitat  unknown.     (Mus.  Cum.  No.  !)">.; 

The  complicated  external  structure  of  the  insertion  plates  is  more 
beautiful  in  this  than  in  any  other  known  species,  resembling  the 
fret-work  of  a  Gothic  pinnacle.  It  is  specially  displayed  where  the 
eaves  have  been  broken  off  through  accident,  and  the  grooving  is 
displayed  under  the  colored  part  of  the  valves,  which  are  there  pec- 
tinated at  the  edges.  It  is  unfortunate  that  the  locality  of  this 
typical  species  is  unknown.  (Cpr.) 

C.  ILLUMINATUS  Reeve.    PI.  9,  figs.  92,  93,  94. 

Shell  oval,  red,  rather  elevated,  the  jugum  acute  ;  umbo  a  little 
in  front  of  the  middle,  slightly  elevated.  Entire  surface  very  min- 
utely wrinkle-striate  and  granulose  under  a  lens,  the  central  areas 
longitudinally,  the  rest  radially.  Central  areas  with  slender  ele- 
vated separated  threads,  parallel  to  the  jugum,  6  to  14  on  each 
side.  Lateral  areas  rather  elevated. 

Interior  roseate.  Anterior  valve  with  15-16,  posterior  with  11-14 
slits,  median  valves  with  1  slit.  Teeth  acute,  quite  distant,  scarcely 
propped.  Eaves  spongy,  sinus  small,  the  sutural  plates  connected 
across  it.  Girdle  normal,  the  scales  rather  large,  solid  ;  sometimes 
spotted  with  paler  at  the  sutures.  (Q>r.) 

Length  16,  breadth  10  mill. ;  divergence  120°. 

Straits  of  Magellan* 

Chiton  illuminatus  REEVE,  Conch.   Icon.   t.   22,  f.    147,1*47.- 
C.  (Callochitoii)  illuminatus  Rve.,  SMITH,  P.  Z.  S.  1881,  p.  35. — 
Lepidopleurus  illuminatus  ROCHEBRUNK,  Miss.  Cap  Horn,  p.  141. 

There  are  about  16  gill  plumes  on  each  side,  reaching  three-fifths 
of  the  distance  forward,  according  to  Carpenter.  In  having  but 
one  slit  in  the  median  insertion  plates  and  in  the  want  of  props  on 
the  teeth  this  species  is  abnormal ;  in  other  respects  it  agrees  with 
Callochiton. 


52  CALLOCHITON. 

Subgenus  STEREOCHITON  Carpenter. 
Stereochiton  CARPENTER  MS.,  1871.—  DALL,  Proc.  U.  S.  Nat. 


Mns.  iss-j,  ,,.  -JM;  (type  C.  castaneus  Wood). 

Valve-  like  Callochiton,  but  the  girdle  leathery  and  downy,  the 
scales  very  delicate  and  deciduous.  In  this  group  the  teeth  are 
numerous,  the  median  valves  having  5  or  more;  but  on  account  of 
tlu-ir  narrowness  they  do  not  always,  have  the  lateral  buttresses  or 
props  outside,  so  characteristic  of  the  teeth  of  the  true  Callochi- 
ton <.  The  eaves  are  very  narrow,  but  distinctly  porous  or  spongy, 
as  in  Callochiton,  and  the  bottoms  of  the  slits  are  also  coarsely 
spongy'.  The  sutural  plates  are  continuous  from  side  to  side,  the 
nir.liaii  sinus  being  a  mere  wave,  also  a  characteristic  of  Callochiton.. 
It  is  therefore  obvious  that  the  characters  of  the  girdle  alone  sepa- 
rate Stereochiton  from  Callochiton.  In  C.  castaneus  the  girdle  of 
moderate  sized  specimens  is  always,  so  far  as  I  know,  denuded  of 
most  of  the  covering  of  downy  scales,  but  under  a  strong  lens  the 
close,  fine  markings  where  they  were  inserted  in  the  girdle  may  be 
seen,  as  well  as  occasional  scattered  scales. 

Stereochiton  externally  resembles  Tonicella,  but  it  may  be  at  once 
distinguished  from  that  group  by  its  numerous  side  slits. 

C.  CASTANEUS  Wood.     PI.  9,  figs.  86-91. 

Shell  oval,  depressed,  dark  chestnut  brown  or  variegated  with 
lighter  brown.  Jugum  obtusely  keeled  ;  lateral  areas  rather  distinctly 
defined,  slightly  raised.  Entire  surface  very  minutely,  densely 
granulated,  when  seen  under  a  lens  ;  the  granules  low,  not  arranged 
in  distinct  lines,  but  an  obscure  oblique  radiation  is  more  or  less 
visible.  Growth  striae  light.  Umbo  of  the  posterior  valve  some- 
what in  front  of  the  middle,  somewhat  elevated. 

Interior  rose  colored;  Anterior  valve  with  20,  posterior  with  18, 
median  valves  with  5  deep  slits.  Teeth  rather  high  and  narrow, 
blunt,  not  propped,  those  of  the  terminal  valves  frequently  bilobed 
or  Lrilobed  inside,  and  obtusely  crenulated  at  their  apices.  Inter- 
stices spongy.  Eaves  very  narrow,  short,  spongy.  Sutural  plates 
connected,  the  jugal  sinus  shallow.  Girdle  leathery,  bearing  (when 
'not  rubbed  off)  delicate  elongated  scales. 

Length  42,  breadth  28  mill. 

Cape  of  Good  Hope. 

Chiton  castaneus  WOOD,  General  Conchology,  p.  13,  t.  2,  f.  2,  3  ; 
t.  3,  f.  L>,  :j,  1815.—  SowERBY,Couchol.Illustr.f.  114,  115.—  REEVE, 


BOHNOOHTTON, 


Conch.  loon.,  t.  f>,  f.  '.>."».  --Nor  <\  <VM/////>;//X  (J.uoy  nor    ('. 
Conth.  —  C.certitiim*  '*//,  •/////.,  RI:I:YI:,  Com-h.  Icon.  f.  i;;j. 

This  Bpeciee  IB  Variable  in  colorinir,  IteinireitlnT  uniform 
brown  or  having  spots  and  patches  of  l)ro\vn  on  a  lighter  Around. 
The  interior  is  always  roseate.  The  numerous  narrow  teeth,  short 
spongy  eaves,  spongy  slits,  etc.,  readily  separate  it  from  other  forms. 

C.  LOBATUS  Carpenter,  n.  sp.     PI.  8,  figs.  83--S-"). 

Shell  large,  flattened,  with  acute  jugum;  intense  olive  colored; 
iimbo  median,  the  posterior  slope  concave.  Valves  scarcely  beaked, 
rounded  at  the  margins.  Lateral  areas  not  well  defined.  Entire 
surface  minutely  granulated  in  quincunx. 

Interior  :  Posterior  valve  with  20,  median  valves  5  to  7  (usually 
6,  the  posterior  minute),  anterior  valve  24  slits.  Teeth  small, 
deeply  separated,  and  outside  very  strongly  propped,  as  if  bilobed  ; 
interstices  deeply  spongy.  Eaves  small,  spongy,  grooved  inside  ; 
sinus  subobsolete  ;  sutural  plates  connected.  Girdle  leathery, 
smooth,  under  a  lens  seen  to  bear  short,  minute,  sparsely  placed 
hairlets.  Length  41,  breadth  27£  mill.;  divergence  130°. 

Tasmania.     (Mus.  Cum.  No  19.) 

This  fine  and  curious  species  has  the  general  aspect  of  Mopalia 
vespertina  (from  which  it  is  known  at  once  by  the  lophyroid 
mucro)  ;  the  insertion  plates,  props,  spongy  eaves  and  minute  sinus 
of  Callochiton  ;  and  a  mantle  resembling  an  aberrant  Tonicia. 

Genus  XI.  ISCHNOCHITON  Gray,  1847. 

=Ischnochiton  +  Tracliydermon  -f-  Maugerella  Cpr. 

Valves  external,  having  sharp,  slit,  insertion  plates,  the  teeth  not 
buttressed.  Eaves  solid  (rarely  somewhat  porous  in  s.  g.  Trachy- 
dermoii)  ;  girdle  covered  with  imbricating  scales,  either  flat  or  con- 
vex, smooth  or  striated.  Gills  typically  extending  the  entire  length 
of  the  foot,  but  in  some  species  they  are  short  in  front  or  at  both 
ends. 

Ischnochiton  is  the  typical  or  central  point  in  development  of  the 
sharp-toothed  division  of  Chitons,  around  which  the  other  genera 
naturally  group  themselves. 

The  great  diversity  in  the  girdle  covering  permits  us  to  use  that 
character  for  the  foundation  of  a  number  of  subgeneric  and  sec- 
tional divisions,  as  follows  : 


54  ISCHNOCHITON. 

Synopsis  of  Subgenera  and  Sections. 
Subgenus  I.  STENOCHITON  Ad.  and  Ang. 

Very  much  elongated,  valves  longer  than  wide,  roundly  arched, 
the  median  valves  having  several  slits;  unibo  subcentral ;  girdle 
covered  with  minute,  smooth  imbricating  scales. 

Subgenus  II.  STENOPLAX  Cpr. 

Elongated,  narrow,  the  posterior  valve  large,  depressed,  with  sub- 
central  or  posterior  umbo.  Girdle  covered  with  small  crowded 
striated  scales. 

* 

Section  Stenoplax  s.  s.    Median  valves  1  slit. 

Section  Stenoradsia  Cpr.    Median  valves  with  several  slits. 

Subgenus  III.  ISCHNOPLAX  Cpr. 

Elongated,  narrow  ;  posterior  valve  elevated,  the  umbo  posterior; 
girdle  covered  with  very  minute  scales,  having  conspicuously  larger, 
striated  scales  mingled  among  them. 

Subgenus  IV.  HETEROZONA  Cpr. 

Shell  like  normal  Ischnochiton.  Girdle  bearing  small  scales 
with  large  striated  scales  intermingled. 

Subgenus  V.  TRACHYDERMON  Cpr. 

Oval ;  valves  having  the  sharp  teeth  of  normal  Ischnochiton  ; 
eaves  narrow,  rarely  spongy.  Girdle  having  very  small  smooth 
scales. 

tion  Trachydermon  s.  s.    Median  valves  having  one  side  slit. 

Section  Trachyradsia  Cpr.  Median  valves  having  more  than  one 
side  slit. 

Subgenus  VI.  ISCHNOCHITON  (Gray)  Cpr. 

Oval  or  oblong;  valves  having  sharp  smooth  teeth  and  solid 
eaves.  Girdle  covered  with  short  flat,  generally  striated  imbricating 
scales  of  moderate  size. 

Section  Ischnochiton  s.  s.     Central  valves  having  one  slit. 

Section  Radsiella  Pils.  Central  valves  having  two  or  several 
slits. 


I8CII\«.«  mi  55 

\'||.    [00H2TORAIMSU  Shuttles. 

Shell  oval,  as  in   Isehnoehiton  ;   irinlle  covered  with  .-olid,  n.rivex, 
smooth  scales,  like  those  of  Chiton  8.  8. 

(ion    lacJiiiui'ttdfiift  s.  s.     Median  valves  having  several  side 
slits.     Type  £  atotro/w Sowb, 

Sretioii  LepidozoiKi    I'ils.      Median    valve-    having   one  side;   .-lit. 
Type  /.  inertensii  Midd. 


Subgenus  I.  STENOCHITON  Adain.s  and   Angas,  18f>4. 

Stenochiton  AD.  AND  ANG.,  P.  Z.  S.  1864,  p.  193. 

Shell  very  much  elongated,  roundly  arched  ;  valves  Ischnoid, 
the  central  valves  havi ng  several  slits  ;  girdle  having  minute  smooth 
imbricating  scales. 

This  section  was  discarded  by  Carpenter,  who  referred  its  only 
species  to  his  own  later  group  Stenoradsia  with  doubt ;  Stenochiton, 
however,  seems  to  have  as  much  individuality  as  most  of  the  divis- 
ions of  Ischnochiton,  and  may  be  allowed  to  stand  as  a  subgenus. 

I.  JULOIDES  Adams  and  Angas.     PI.  16,  figs.  6,  7,  8. 

Shell  much  elongated,  narrow,  narrower  in  front;  rufous  brown, 
minutely  spotted  with  white.  Valves  narrow,  longer  than  wide, 
very  convex,  not  carinated ;  lateral  margins  scarcely  rounded,  pol- 
ished. Lateral  areas  elevated  and  at  the  margins  concentrically 
sulcate.  Girdle  narrow,  pale-brown,  spotted  with  black-brown, 
covered  with  very  minute,  polished,  imbricating  scales.  (Ad.  and 
Ang.)  Length  25,  breadth  6  mill. 

Holdfast  Bay,  South  Australia. 

Stenochiton  juloides  AD.  AND  ANG.,  P.  Z.   S.  1864,  p.   ?93  ;  I.  c. 
1865,  p.  58,  t.  11,  f.  15.— ANGAS,  P.  Z.  S.  1865,  p.  188.— "  f  St* 
adsia  "  juloides  Ad.  and  Ang.,  CPU.  MS. 

This  species,  from  its  narrow,  convex  form  and  polished  surface 
has  much  the  general  appearance  of  a  Myriapod.  (Ad.  and  Ang.) 

This  species  is  the  type  of  the  genus  Stenochiton  Adams  and 
Angas,  which  is  thus  characterized  by  them:  "Shell  elongated, 
narrow,  convex  ;  valves  longer  than  wide,  not  carinated;  apex  of 
the  posterior  valve  subcentral ;  plates  of  insertion  small,  multi- 
fissate  in  the  end  valves,  the  intermediate  valves  having  T>  li- 
on each  side;  girdle  covered  with  very  minute,  polished,  imbrica- 
ting scales." 


56  ISCHNOCHITON. 

Carpenter  gives  the  following  notes  on  the  type  specimen  :  Length 
22*,  breadth  4 '  mill. ;  shell  very  narrow,  elongate,  elevated,  cylin- 
drical, the  juguni  rounded  ;  red-brown,  narrowly  streaked  with 
paler.  Posterior  valve  elongated,  mucro  median,  scarcely  conspic- 
uous, the  slope  behind  it  straight.  Anterior  valve  forming  more 
than  a  semicircle,  its  posterior  margin  (suture)  emarginate.  Entire 
surface  delicately  granulated  in  quincunx;  jugal  area  scarcely 
defined ;  lateral  areas  conspicuously  elevated.  Girdle  inconspic- 
uous, covered  with  minute  imbricating  scales.  Scales  almost  all 
destroyed,  but  looking  like  those  of  /.  sanguineus,  etc.  Sinus 
large,  very  deep,  flat,  wide;  sutural  plates  much  elongated,  narrow. 
Central  valves  regularly  3-slit;  posterior  valves  about  16,  anterior 
valves  about  13  slits.  The  slits  are  irregular,  sometimes  bifurcating 
but  typically  rather  distant.  Teeth  very  acute,  moderately  long. 
Eaves  moderate. 

Subgenus  II.  STENOPLAX  Carpenter,  1878. 

=  Stenoplax  Cpr.  -f  Stenoradsia  Cpr.  -f-  Maugerella  Cpr. 

Elongated,  narrow  Ischnoids,  having  the  girdle  covered  with 
minute,  crowded,  imbricating  striated  scales.  Median  valves  having 
the  lateral  areas  much  raised ;  posterior  valve  large,  depressed,  the 
mucro  subcentral  or  slightly  posterior. 

The  subgenus  Stenoplax  (-f-  Stenoradsia  and  Maugerella)  has  a 
very  characteristic  peculiarity.  The  sides  and  front  end  of  the  foot 
are  so  much  dilated  that  the  head  of  the  animal  is  nearly  or  entirely 
concealed  from  below,  the  thin,  produced,  anterior  end  of  the  foot 
extending  quite  over  it  The  gill  row  is  shortened  at  both  ends, 
reaching  nearly  to  the  head,  but  shortened  at  the  tail  about  one- 
fourth  the  entire  length  of  the  foot.  .The  branchiae  are  largest  at 
the  middle. 

STI:N< 'iM.  \x  divides  naturally  into  two  sections:  (1)  Section 
>plax  (restricted),  in  which  the  median  valves  have  a  single 
>lit  on  each  side,  and  (2)  Section  Stenoradsia,  the  species  of  which 
have  two  or  several  side  slits  in  the  median  valves. 

Section  Stenoplax  Cpr.  (restricted). 

-  noplax  CPU.,  MS.  and  table  of  Regular  Chitons,  1873. — DA  LI., 
,U.S    Nat.  Mns.  1878,  p.  330,  type  /.  limaciformis  Sby. 
This  section  is  closely  allied  to  Stenoradsia,  the  latter  differing 
only  in  having  several  slits  in  the  plates  of  the  intermediate  valves. 


ISCHHOCHITOH. 

I.    I.IMA<   ll'oKMI-  Si.wrrhy.        PI.    Hi,   fi.LTS.   •'     I'J. 

Shell  rl.m'jaled  and  narrow,  elevated,  well    areh.  d  :    bull 
irreriiish,  indistinctly  marldrd  with  darker,  and  occasionally  blotehed 
with  red;   longitudinally  costulate,  not    graiiosc  ;   <_rirdl< 

minute. 

The  sculpture  upon  the  central  areas con>ists  of  line,  close,  smooth 
lon-itudinal  rildets;  these  continue  upon  the  lateral  areas,  becom- 
ing broader  and  Hat  there,  and  being  decidedly  waved  or  irregular 
on  the  slope  between  central  and  lateral  areas.  The  end  valves  are 
sculptured  with  close,  flattened  concentric  ridges,  which  are  more 
or  less  wavy  or  irregular.  The  lateral  areas  are  well  raised,  and 
are  separated  by  a  considerable  space  at  the  jugum.  The  mucro  is 
subcentral  and  low. 

Interior  stained  with  bright  pink  and  blue-green  ;  sutural  plates 
well  developed ;  sinus  flat,  angular,  wide;  anterior  valves  with  11, 
central  valves  1,  posterior  valves  9  slits.  Teeth  sharp,  smooth  ; 
eaves  grayish,  solid. 

Girdle  covered  with  extremely  minute  subequal  scales. 

Length  35,  breadth  12  mill. 

Length  25,  breadth  10  mill. 

Florida  Keys ;  St.  Thomas,  St.  Vincent  and  West  Indies  gener- 
ally;  Central  America  and  Peru;  under  stones  at  low  water. 

Chiton,  limaciformis  SOWERBY,  P.  Z.  S.  1832,  p.  26;  Conchol. 
Illustr.  f.  38. — KEEVE,  Conch.  Icon.  t.  8,  f.  42. — Ischnochiton 
ciformis  SHUTTLEW,  Bern.  Mittheil.  1853,  p.  190. — 
(Stenoplax)  limaciformis  Sowb.,  CPR.  MS.,  and  DALL,  Blake  Gas- 
trop.  p.  415. — Ischnochiton  multico status  Ad.,  DALL,  Proc.  U.  S. 
Xat.  Mus.  vi,  p.  337,  1883,  not  of  C.  B.  Adams. —  Chiton  prodwhi* 
Ilr.KVE,  Conch.  Icon.  t.  17,  f.  97,  1847. —  Chiton  sanguineus  Ki  i:\  i:, 
/.  c.  f.  98. — f  Lepidopleurus  sanguineus  CPR.,  Ma/.  ( 'atal.  p.  1(.>4. 

The  West  Indian  specimens  collected  by  Robert  Swift  at  St. 
Thomas,  and  the  Peruvian  specimens  which  I  have  examined  are 
absolutely  identical  in  character  except  that  the  former  are  finely 
mottled  with  pink,  and  one  specimen  is  heavily  blotched  with  crim- 
son on  the  second  and  tail  valves  (fig.  9).  Another  tray  from  the 
Swift  collection  contains  pale  but!'  examples  with  faint  darker 
markings.  Carpenter  has  reported  the  same  species,  or  one  very 
closely  allied,  from  Ma/at  Ian  and  from  Japan.  The  last  certainly 
requires  confirmation. 


58  ISCHNOCHITON. 

The  characteristic  mark  of  this  species  is  the  sculpture  of  the 
lateral  areas  and  end  valves,  which  are  non-granulated  but  have 
slightly  serrated  concentric  flat  riblets.  The  girdle  scales  are  flat, 
solid,  not  striated  or  very  obsoletely  so,  and  far  more  minute  than 
in  /.  n /ut  n.-: 

I.  FLORIDANUS  Pilsbry,  n.  sp.     PI.  17,  figs.  19-22. 

Shell  elongated,  narrow,  elevated,  the  valves  roundly  arched,  not 
carinated.  Color  whitish  or  delicate  green,  variously  marked  and 
mottled  with  olive,  blackish-olive  or  gray. 

The  lateral  areas  are  raised,  longitudinally  costulate,  the  riblets 
cut  into  granules  by  radiating  impressed  or  incised  lines  devel- 
oped over  the  whole  area  or  over  the  forward  half  of  it.  End  valves 
similarly  cut  into  granules  by  radiating  and  concentric  lines.  Cen- 
tral areas  covered  with  longitudinal  riblets  which  are  finer  and 
closer  upon  the  jugum,  usually  showing  a  tendency  to  be  a  little 
irregular  on  either  side  of  it,  and  are  granulous  toward  the  outer 
angles  of  the  areas.  Posterior  valve  large,  rather  depressed,  the 
mucro  slightly  posterior. 

Interior  pink,  blue  and  white,  in  various  proportions,  rarely  all 
roseate  or  all  white.  Sutural  plates  strongly  developed,  rounded  ; 
sinus  wide,  deep,  square.  Anterior  valve  having  9,  central  valves 
1,  posterior  9  slits;  teeth  sharp,  smooth  or  very  obsoletely  lobed. 
Eaves  narrow,  solid. 

Girdle  delicately  marbled  with  bluish  and  gray,  densely  clothed 
with  rounded,  solid,  delicately  striated  scales. 

Length  41,  breadth  15  mill. 

Length  35,  breadth  1U  mill. 

Key  West,  Florida.     (Hemphill.) 

This  species  is  allied  to  J.  limaciformis,  differing  in  the  differently 
sculptured  lateral  areas.  It  is  also  related  to  C.  purpurascens  C. 
B.  Ad.,  but  differs  in  several  respects,  notably  in  the  flatter  poste- 
rior valve  and  longer  central  valves. 

I.  i-L'RPURASCENS  C.  B.  Adams.     PI.  17,  figs.  23,  24. 

Shell  <-l<>iiLrat<Ml,  narrow,  much  elevated,  the  lateral  slopes  of  the 
valves  nearly  straight,  dorsal  ridge  roundly  subangular.  Generally 
pale  buff,  marbled  with  olive  or  mottled  with  black,  and  having  red 
patches  along  the  dorsal  ridge.  The  lateral  areas  are  raised  and 
longitudinally  ribbed,  the  riblets  cut  into  granules  by  radiating 
impressed  lines;  end  valves  cut  into  coarse  granules  by  radiating 


m  IIN<>< mi  59 

and  (M.ncciitfic  lines.     Central  areas  having  tin-  dorsal  ridi" 

or   only  minutely  punehired  ;   the  longitudinal  riUets  of  the  lateral 

area-    extend    forward  Upon  the    "pleura"    or    lidet    "|    tbc    e.-ntral 

areas.       Posterior    valve    elevated,    the    IMIICTO    .slightly    posterior, 

elevated. 

Interior  white  or  stained ;  sutural  plates  short;  sinus  wide,  tlat. 
Anterior  valve  having  10,  central  valves  1,  posterior  valve  ID  -lii~. 
Teeth  sharp,  smooth.  Eaves  narrow. 

Girdle  rather  wide,  alternately  bluish  and  buff,  densely  clothed 
with  minute,  solid,  striated  scales.  Length  16,  breadth  7  mill. 

Jamaica  (Adams)  ;  Key  West,  Florida  (Hernphill ;  Rush.) 

Chiton  ]>iii-]>iir<i8cens  C.  B.  ADAMS,  Proc.  Boat.  Soc.  N.  II.  ii,  p. 
9,1845. — Ischnochiton  purpurascens  Ad.,  DALL,  Bull.  I.  S.  Nat. 
Mils'.  No.  37,  p.  172, 

Adams'  description  is  as  follows  :  Shell  much  elongated,  purplish- 
ruddy,  concentrically  striated  ;  margin  wide,  very  minutely  scaly, 
bluish,  alternately  paler.  Length  I'l,  breadth  '5  inch. 

This  species  differs  from  /.  floridanus  in  having  all  of  the  valve- 
decidedly  shorter  and  broader ;  the  posterior  valve  much  more 
elevated,  the  jugum  almost  smooth.  It  differs  from  /.  lirnaciformis 
in  having  the  lateral  areas  and  end  valves  conspicuously  granulose, 
etc. 

In  this  species  the  valves  are  almost  as  short  as  in  the  typical 
Ischnochitons,  but  the  sculpture  is  quite  that  of  Stenoplax.  The 
mucro  is  more  raised  than  in  any  other  described  Stenoplax.  The 
species  is  abundant  at  Key  West. 

The  color-pattern  is  excessively  variable. 

I.  FALLAX  Carpenter,  n.  sp.     PI.  16,  figs.  17,  18. 

Almost  exactly  like  Ischnochiton  magdalenensis  in  form  and  sculp- 
ture, but  more  roseate ;  the  central  areas  pitted ;  lateral  areas 
having  close  radiating  wrinkles  interrupted  by  lines  of  growth. 
Interior:  Posterior  valves  having  9,  central  1,  anterior  10  slits; 
teeth  acute  ;  eaves  conspicuous ;  sinus  moderate,  scarcely  laminate, 
but  the  jugal  part  of  the  valves  produced  forward.  Girdle  having 
very  minute  granules. 

Length  27£,  breadth  12*  mill. ;  divergence  120°. 

Monterey,  California. 

The  color  is  either  entirely  reddish-ilesliy  or  clouded  and  dotted 
with  olive  and  whitish.  The  main  distinction  between  this  form 


60  ISCHNOCHITON. 

and  /.  magdalenensis  is  that  the  latter  lias  radsioid  valves  and  coarser 
girdle  scales.  (  'arpenter's  description  is  given  above,  and  the  fig- 
ures represent  the  type  specimen. 

The  foot  is  produced  forward,  and  the  gill  row   is  short  at  both 


I.  A  i.  ATCS  Sowerby.     PI.  16,  figs.  1-5. 

Shell  much  elongated,  narrow,  elevated,  rather  thin.  On  a  light 
Mi-shy  hut!'  or  greenish  ground  it  is  delicately  marbled  and  mottled 
with  olive  or  olive-green.  The  sculpture  consists  of  longitudinal 
close,  narrow  ridges,  which  are  finer  on  the  dorsal  ridge,  and  clump 
to  an  irregular  granulation  on  the  lateral  areas  and  terminal  valves. 
The  lateral  areas  are  decidedly  raised  ;  the  jugal  area  is  divided 
from  the  pleura  by  a  change  in  sculpture,  which  becomes  coarser 
and  more  or  less  divaricating,  sometimes  forming  a  cellular  pattern 
at  the  edges  of  the  jugal  area  and  on  the  slopes  of  the  lateral  areas. 

Interior  rose-pink,  rarely  almost  white;  anterior  valve  having  9, 
central  1,  posterior  valve  9  slits.  Teeth  sharp,  eaves  moderate, 
solid.  Sutural  plates  large,  rounded  ;  sinus  very  deep,  narrow. 

<iirdle  wide,  thin,  covered  with  fine,  even,  short,  striated  solid 
scales, 

L.-ngth  57,  breadth  16  mill. 

Length  40,  breadth  16  mill. 

Islands  of  Siquijor  and  Zebu,  Philippines,  under  stones  at  low 
water. 

Chiton  alatus  SOWERBY,  P.  Z.  S.  1841,  p.  61.—  RVE,  Conch.  Icon. 
t.  8,  f.  45.—Is«hnochiton  alatus  GRAY,  P.  Z.  S.  1847,  p.  127,  and 
/.  n/tu8  Gray,  Guide,  p.  1  82.—  Stenoplax  alata  CPR.  MS. 

The  solid,  deeply  striated  scales  of  the  girdle  are  very  character- 
i-tic,  as  is  also  the  sculpture.  The  pattern  of  color  is  an  indefinite 
and  variable  mottling.  Figures  3,  4,  5  are  drawn  from  a  typical 
specimen  received  from  Sowerby.  Figures  1,  2  are  from  draw- 
ing made  for  Carpenter,  and  represent  the  scales  as  much  more 
elongated,  and  the  head  valve  as  less  emarginate.  1  am  disposed 
to  believe  that  this  last  peculiarity  is  a  mistake. 

The  sole  is  produced  forwa  rd  as  far  as  the  month;  head  Me>hy  : 
veil  copious,  neck  lappets  long.  Gills  about  one  valve's  luvadth 
removed  from  neck  and  the  same  at  tail.  Vent  inconspicuous. 
Foot  fleshy,  projecting. 


[01   ll\...   ill  i  , 

1  ferpeoter,  1*7*. 


,    i/\.  mid  tahl.-  of  i;«-  ci.it  : 

Proc.  r.  s.  N:,t.  M.IS.  I.STS,  P.  830,  type  G  maj  B 

—M<tu<i<-,;ii«  c\'\i.  .J/x.  and  table  of  Reg.  Chi'toof,  type  .i/ 

Cpr.  .l/.S'.—  Iwhnortnltin  (in  pan    .  SIM   i  i  i.i.u  ..  I  '„  m.  Mill  heil.  ! 
p.  86, 

Like  Stenoplax,  hut  intermediate  ralvee  1  1  aving  several  rid 
The  Uadsioid  valves  alone  di.-iin_iruisli    tliis   from  Stenoplax.     Its 
relations  \\itli  the  Australian  Stenochiton.  jntuid<'»  an;   jirolmlily  not 
especially  close. 

In  one  species,  /.  conspicuus,  the  mantle  scales  have  Ixrn   ti 
formed  into  slicrt,  round,  striated    bristles,  and    on   account   oftlii- 
modification  Carpenter  established  for  it  a  subgenus  under  Chceto- 
jt  /en  rn  which  he  called  Maugcrella.  We  are  com  pel  led  to.-nppr«-.-  thi* 
group  because  of  the  excessively  close  relationship  <-xi.-tinir  lM-t\\«-«-n 
/.  conspicHitx  and  the  two  species  of  genuine  Sten- 
and  /.  magdalenensis. 

I.  ACRIOR  Carpenter,  n.  sp.    PL  14,  figs.  86-89. 

Shell  much  like  /.  magdalenensis,  but  broader  and   flatter,  with 
much  sharper  sculpture.     Olive-green,  pink   where  worn,  or  > 
times  light  flesh-colored,    with  the  jugum   or  central  areas  often 
green.     Girdle  dark  ashen  or  olive. 

The  anterior  valve  is  notably  concave,  as  in  /.  conspicuus.  Tin- 
lateral  areas  are  much  raised,  and  sculptured  with  acute  radiating 
riblets,  sometimes  splitting;  central  areas  having  acute  longitudinal 
riblets. 

Interior  pink,  with  a  blue  spot  at  the  jugal  sinus.     Sutural  p! 
wide,  pink;  sinus  broad,  deep,  angular.     Anterior  valves  having 
13-15,  central  valves  2-4,  posterior  valves  10-13  slits.     Teeth  long, 
sharp,  smooth.     Eaves  wide,  dark-blue. 

Girdle  wide,  tough,  covered  with  very  small,  solid,  shot 

Length  110,  breadth  55  mill. 

Length  75,  breadth  40  mill. 

Cerros  (Cedros)  Island  to  Cape  St.  Limn.*,  Lower  California, 

StenoradsiaacriorCpR.MS.  —  Chiton  iintfjd'i/eneimiin  part    Ki  i 
Conch.  Icon.  t.  4,  f.  20a,  not  of  Hinds. 

This    species     represents    one  extreme  of   variation    of   the    / 
magdalenensis  type,  the  other  extreme  being  7.  con^»icun.<.     1  i 


62  ISCIINOCHITON. 

still  to  see  specimens  truly  ronnoctinir  the  three  forms,  although 
they  arc  doubtless  closely  allied.  The  present  form  differs  from 
}n>igd'ilenen*is  in  having  a  concave  head  valve,  strong,  distinct, 
acute  riblets  upon  the  central  areas,  and  a  generally  more  robust 
A  th. 

/.  t  '•«  also  has  a  concave  head  valve,  but  the  sides  of  tin- 

central  areas  show  no  sculpture  except  microscopic  granulation, 
and  the  scales  of  the  girdle  are  pulled  out  into  true  spines  or  bris- 
tles. 

There  is  a  light  form  of  acrior  which  is  fleshy-white,  the  girdle 
gray-white  or  dark  ;  and  some  of  these  have  the  jugum  or  the  cen- 
tral areas  of  the  normal  green-olive  color  (fig.  89.) 

1.  M A.-I.AI  KNKNSIS  Hinds.     PI.  15,  figs.  98,  99,  100. 

Shell  elongated,  rather  narrow,  generally  faintly  mottled  with 
delicate  olive  on  a  light  greenish,  blue  or  pinkish  ground.  Interior 
bluish,  white  or  pink.  Lateral  areas  and  end  valves  having  radia- 
ting riblets,  central  areas  finely  pitted. 

The  lateral  areas  are  distinctly  raised,  radiately  delicately  ribbed. 
Front  slope  of  the  anterior  valve  straight.  Central  areas  having  a 
more  or  less  developed  system  of  branching  reticulating  wrinkles  pro- 
ilncnig  oblong  or  diamond- shaped  pits.  Umbo  of  posterior  valve 
central,  but  little  projecting. 

Interior :  Sutural  plates  well  developed,  the  sinus  deep,  angular. 
Anterior  valve  having  10-13,  central  valve  2-4,  posterior  valve 
10-12  slits. 

Girdle  having  fine,  close,  solid  imbricating  scales. 

Length  75,  breadth  30  mill. ;  divergence  about  130°. 

Length  55,  breadth  27  mill. 

Monterey,  California,  south  to  Magdalena  Bay;  Catalina  and 
Sta.  Barbara  Is. 

Chiton  magdalenensis  HINDS,  Zool.  Voy.  'Sulphur'  ii,  p.  54,  t. 
1 :».  t.  1 .  REEVE,  Conch.  Icon.  t.  5,  f.  20b. — Stenoradsia  magdalen- 
ensis CPR. — S.  "magdalensis"  Ki;i:r,  West  Coast  Shells,  p.  107,  f. 
94,  and  of  collectors  generally. 

This  species  differs  from  /.  conspicuus  in  its  pitted  instead  of  finely 
granulose  central  areas  and  in  the  mantle-covering  of  minute,  solid 
scales,  unlike  the  short  spines  of  the  other  form.  It  differs  from  7. 
•  /•  in  the  much  finer  sculpture  and  more  delicate  coloring. 


rSOHNOCHT]  »'».'! 

Tin-  loot    projects  foruard,  conceal!  MI:  tin-  lim.j  tV-.m   bttN  :itli. 

I.  .  02XBPX4  GUfl  Carpenter,  n.  ip,      I'i 

Shell  lar^e,  elongated.  moderately  elevated;    greei 


earthy-brown  ),    luit    \\  lien-  eroded  at  tin-  heaks  it  i^  pink.      In! 
pink,    witli    a    blue    spot    at    tin-   juiral    -inn-.        Lateral  an-as  much 
raised,    having  acute  radiating  rilil.  : 
enlly  *mnnih,  but  microscopically  -rauulated,  BOtQetitiK 

faint   longitudinal  strice  at  the  jogum,     Front  */ope  of  th< 

i'<i  /re  en/icdi'f  ;  yirdle  densely  beset  with  short  bristles,  <,  <>  vet- 

1'i'tll  nfJiCrt. 

The  entire  surface  is  very  densely  miero-eopieally  granulated, 
where  not  eroded.  The  lateral  areas  have  fine  aeute  radii  and 
often  the  back  edge  of  each  valve  is  crenulated  by  oblique,  sharp, 
little  folds.  The  color  is  often  varied  by  darker  little  flame-  on  tin- 
central  areas.  The  posterior  valve  is  large  and  depressed. 

The  sutural  plates  are  large,  the  sinus  deep  and  angular.     Inser- 
tion plates  having  in  anterior  valve  9,  central  valves  2  or  3,  j> 
rior  valve  10  slits.     Teeth  sharp  and  thin  in  posterior  and  central 
valves,  but  blunt  and  bi-  or  trilobed  in  anterior  valve.     Eaves  wide. 
solid,  light  blue-green  colored. 

Length  82,  breadth  36  mill. 

Length  89,  breadth  41  mill. 

Santa  Barbara,  California,  t<>  Magdalena  Bay. 

Maugerella  conspicua  CPR.  MS.  —  OROUTT,  Proc.  U.  S.  Nat.  Mu>. 
1885,  p.  544. 

This  species  may  be  separated  from  /.  amor  by  its  unsculptund 
central  areas  and  velvety  rather  than  scaly  girdle.  It  is  more 
closely  allied  to  I.  magdalenensis  and  may,  indeed,  prove  tointergrade 
with  that  species;  but  in  magdalenensis  the  front  valve  is  scar 
concave  in  front,  the  sides  of  the  central  areas  have  a  honeycomb 
sculpture,  and  the  girdle  is  very  finely  sc<ilij,  not  re  I  ret;/. 

A  specimen  before  me  from  Magdalena  Bay  is  ferruginous 
brown,  the  central  areas  are  more  rugose,  and  the  -i/.  i-  unalfer, 
length  45,  breadth  20  mill.  Another  specimen  has  the  central 
areas  sculptured  like  /.  acrior,  but  less  strongly;  the  Birdie  being 
bristly,  however,  as  in  typical  eow.<;m-H"-<.  S:m  Diego  may  be 
regarded  as  the  center  of  distribution  of  this 


rpenter  ha-  i:ivn  a  varietal  mum-  to  a  broad,  worn   specimen, 
which  he  thus  describes  : 

Var.  solidus  (pi.  15,  fig.  97).  Very  solid,  wide,  ashen;  inside 
whitish,  the  posterior  valve  with  10,  central  valve  2-3,  anterior 
valve  12  slits.  Length  72,  breadth  40,  divergence  130°. 

Carj»  at*  /•/»/,  near  Sta.  Barbara,  California. 

This  is  scarcely  more  than  an  individual  variation.  The  figure 
ivpn-mts  the  valves  only  of  the  type  specimen.  The  mantle  is 
normal.  The  sculpture  is  worn  away  except  at  the  edge.  It  has 
evidently  lived  in  a  very  exposed  situation. 

Suhgenus  III.    ISCHNOPLAX  Carpenter. 

LchnnjJ,i.r('i-ii.  (Table  of  Reg.  Chit.  1873),  DALL,  Proc.  U.  S. 
Mus.  1878,  p.  330,  type  C.  pectinatus  Sowb. 

Body  elongated,  elevated,  the  valves  having  high  suttirM  plates 
ami  strongly  elevated  lateral  areas;  mucro  posterior,  elevated; 
girdle  clothed  with  very  minute  imbricating  scales  and  having  larger 
conspicuous  striated  scales  scattered  among  them. 

The  girdle  is  like  that  of  Heterozona,  but  the  valves  and  general 
shape  are  similar  to  Stenoplax,  except  that  the  mucro  is  posterior 
and  elevated,  a  character  recalling  Callistockiton. 

I.  i  IX-TINATUS  Sowerby.     PL  17,  figs.  25-30. 

Shell  elongated,  narrow,  elevated ;  gray,  mottled  and  dotted  all 
over  with  black,  more  or  less  stained  in  places  with  pink. 

The  valves  are  strongly  convex  ;  end  valves  radiately  coarsely 
granose-ribbed  ;  umbo  of  posterior  valve  elevated,  situated  behiu<! 
the  center.  Lateral  area  much  raised,  having  radiating  granose 
riblets  ;  central  areas  having  smaller  cords,  which  are  close  and  lon- 
gitudinal on  the  jugum,  but  become  more  spaced,  coarser,  and 
[liny  on  the  pleura  or  sides  of  the  central  areas. 

Interior  bright  pink.  Anterior  valve  with  in- 12,  intermediate 
valve  1,  posterior  valve  8-11  slits.  Teeth  sharp,  frequently  bifid  ; 
eaves  unusually  wide,  solid,  scalloped  by  the  sculpture  of  the  out- 
side. Sut  u nil  plates  high,  rounded.  Sinus  deep,  square. 

Girdle  (pi.  1 7,  figs.  28, 29)  covered  with  extremely  fine  scales  among 
which  larger,  long  fiat  scales  are  irregularly  scattered. 

Length  36,  breadth  16  mill. 

Length  40,  breadth  17  mill. 

Cuba  (Cuming) ;  Guadeloupe  (Swift)  ;  Barbados  (Rush). 


DBOHVO4  HI  i' 

Chifnn  /><><•(  in, it  //.<  S«,\\  I ;..   M  a-.  ,  ,f  N  ill .     I  I  i~f .,  .lime.    |S-lU.    p.   : ' 
t.    1C.,    t'.   :i  ;    Conch.  Illustr.  ('.    1  1C,.       |;, .,  \  ,  .  (  ',,, ,,.),.   I 

1 83,     '  '•    /-•'•hnn.'hitiiii  i  pectinatu*  SIM  n  u.\\ .,  Hem.  Mitthdl.  I 

|t.      77. — •I.tf'hnniilii.r      }irrtiu'lfu.i      CPB.,        M>. —  Chiton       ncnti/i, 

KI:I;\I:,  Condi.    Icon.  t.   *,   f.   Mt.--Chitnn  miill'u-n*tuhi#  ('.  \\.    Ah., 

Proo,  r.«.st.  Boo,  N.  II.  ii,  |».  8,  ! 

LVadily  known    from  other    \Ve>l   India   ( 'hitons  liv    its  dong 
r.inn,   speckled    and    mottled  coloring,   SUM!   especially    \>\-   the 
peculiar  ^irdlo.     The  larirf  scales  are  distinctly  but  finely  Mriated. 
The   grOUnd-Oolor  of  the  girdle   is  pale   bufl',  with    patches  of  olive- 
ii'reen.     The  larLie  scales  are  mingled   white  and  buff  on  the  liirlit 
tracts,  and  are  a  dark  blue-green  on  the  dark  patches. 

Reeve's  C.  acutiliratm  (fig.  30)  is  a  typical  pcH'n,<ihi.<.     \    have 
not  seen  the  Ch.multicostatus  of  C.  B.  Ad.,  described  from  .Iain; 
and  the  description  is  too  meager  to  permit  certainty  in  referring  it 
here. 

Subgenus  IV.  HETEROZONA  Carpenter,  1878. 

Heterozona  CPR.  (Table  of  Regular  Chitons,  1 873),  DALL,  Proc. 
T.  S.  Nat.  Mus.  1878,  p.  331.  Type  H.  cariosa  Cpr.  MS. 

Shell  like  normal  Ischnochiton  ;  girdle  bearing  small  scales  with 
large  striated  scales  intermingled. 

The  girdle  is  that  of  Ischnoplax,  but  the  shell  is  not  elongated, 
and  the  umbo  of  the  posterior  valve  is  median,  not  posterior.  The 
arrangement  of  scales  normal  in  this  section  is  the  same  as  a  patho- 
logic condition  sometimes  met  with  in  individuals  of  species 
normally  having  regular  and  equal  scales,  but  in  which  the  girdle 
has  been  injured;  the  injury  being  repaired  with  scales  much 
smaller  than  those  upon  the  healthy  portions  of  the  girdle. 

I.  CARIOSUS  Carpenter,  n.  sp.     PI.  24,  figs.  20,  21,  *2'2. 

Shell  oblong,  rather  elevated,  the  valves  broadly  arched  and 
rounded  dorsally.  Color,  soiled  yellowish,  unieolored  or  with 
indistinct  brown  spots. 

The  lateral  areas  are  raised,  and  sculptured  with  a  var\  in-  num- 
ber (about  7)  of  radial  ribs,  which  are  irregular,  often  splitting. 
and  very  unevenly  granose.  Central  areas  finely  granulated  upon 
the  dorsal  ridge,  the  granulation  giving  place  on  the  side-slopes  to 
a  rather  strong  but  fine  corrugation  ;  the  wrinkles  longitudinal, 
but  converging  forward  toward  the  middle:  and  minutely  irregular 
5 


or  undulatiDg.  Toward  the  outer  edges  the  wrinkles  become 
ler  and  more  separated.  End  valves  sculptured  with  radiating 
riblet> :  posterior  valve  having  the  macro  central.  Interior  white, 
the  end  valves  usually  marked  with  a  brown  crescent;  sutural  lobes 
rounded  ;  sinus  wide  and  flat.  Anterior  valve  having  12,  median 
valves  1,  posterior  valve  12  slits;  teeth  smooth,  rather  .-harp. 
Kaves  solid. 

(iirdle  covered  with  flattened  striated  scales,  which  are  verv 
unequal  in  si/.c,  but  become  larger  toward  the  valves  (fig.  21). 

Length  32,  breadth  HI  mill. 

Australia, 

The  texture  of  the  shell  is  peculiar,  the  outer  layer  being  thin 
and  easily  broken  through,  exposing  an  extremely  spongy  layer. 
(  arpenter's  specimens  seem  to  have  been  worn  so  as  to  expose  this 
layer  in  places,  hence  the  name  cariosus.  In  the  normal  and  un- 
worn specimens  before  me  the  outer  surfare  is  scarcely  carious 
though  dull  and  uneven,  nor  are  the  eaves  spongy.  Carpenter's 
original  description  is  as  follows: 

Heterozona  cariosa  (pi.  24,  fig.  23).  Shell  subelongate,  rather 
elevated,  the  jugum  rounded.  Mucro  median,  moderately  elevated  ; 
whitish-ashen,  slightly  variegated  at  the  sutures  occasionally. 
Central  areas  very  granose  in  a  young  specimen,  the  granules 
minute  and  close  toward  the  jugum,  then  becoming  rugose  lines, 
undulating  anteriorly,  and  widely  separated  on  thesides;  the  adult 
shell  is  carious.  Lateral  areas  having  3-8  deeply  but  irregularly 
granose  radii,  the  grains  at  the  sutures  large;  end  valves  having 
30-40  graniferous  radii.  Interior:  posterior  valve  with  11,  central 
1,  anterior  valve  11  slits.  Teeth  acute;  eaves  wide,  spongy;  sinus 
large,  flat,  smooth.  Girdle  (pi.  24,  fig.  23),  clothed  with  nornal 
striated  imbricating  scales  and  having  long,  large  striated  solid 
scales  scattered  here  and  there.  (Qt?r.) 

Length  30,  breadth  161  mill.,  divergence  100°. 

Australia  (Mus.  Cuming  No.  46). 

This  shell  forms  an  exact  transition  between  Ischnoplax  and  the 
true  Ischnoehiton.  The  mantle  resembles  Ischnoplax  in  its  double 
series  of  scales ;  although  if  the  large  ones  were  plucked  out,  the 
latter  would  be  nearly  of  a  normal  arrangement,  except  that  they 
aiv  rather  nariow  a-  in  /.  castns.  It  differs  from  7>r///>oy,A/.r,  not 
only  in  not  lu-in^  narrow  and  elongated,  but  in  having  a  normal 
IIMKTO.  The  species  is  curiously  like  Stciiormltn'n  magdalenentis, 


HNO  in  i' 

younir,  ill  .-hape  :in<l  plan  of  .-ruljil  HIT,  l»ut  the  Scales  :i 
and  the  central  valves  have  only  OIK-  .-lit.         ' 
Carpentrr'-    .!>  -eripljnii     an<l     Bgtm    dill!  r    SMI: 

specimens  before  me,  described  ahove.     li'  the  Ian 

cally  distinct  it  may  he  called   /.  Bttbcaric 


Siihgrnus  \'  .    Ti:  ACII  YI>I:I:M<>\  (  'arpenter,  1863. 


.,   Kep.   l',rit.  &MO.    Adv.    Sri.    L863,    p, 
G.    O.    SABS,    Moll.  lie-.  A  ret.  Norv.  p.  1  i 
IVmi.  -  -  cinereus  L.).  —  Boreochiton  S\i;-    in  ; 
p.    lit!   (proposed   for    C.  ruber  Lowe  and  C.  marmoreiu  Fahr.;.  — 
(liitoii,  Lepidoplewrus,  Leptochiton,  Ischnochitnn  and  /,'>/>//>//•" 
•  •!'  various  authors. 

Valves  exactly  like  those  of  Ischnochifou,  hoth  diitside  and 
within:  girdle  having  the  scales  very  small,  close  and  sim...tli. 
(Jills  from  one-half  to  over  three-fourths  the  length  of  the  ; 

This  irroup  was  originally  proposed  as  a  suhgenusof  I.«r]nnn-1, 
and  the  following  species  referred  to  it:    refij><>r<>.<n.-<  Cp 
stinctus  Old.,   trifidus  Cpr.,  dentiens  Old.,  gothicus  Cpr.,  h<irt> 
(1pi-.,  unltxUii  Cpr.,  flectens  Cpr.     Carpenter  subsequently  stated 
that    Trac.hydermon    was   equivalent  to   Gray's  second   section  of 
Ischnoehiton,  "  **  scales  of  mantle  minute,  granule-like."      (1*.   /. 
S.  1847,  p.  127),  this  section  containing  only  the  species  P.  >//'//•'/'/'- 
»////x      C.  cinereus  L.  and  Lowe.  Still  later,  Carpenter  raised  the  group 
to  the  rank  of  a  genus,  adding  to  his  diagnosis  the  words  "gill-  short." 
It  is  evident  that  a  type  species  for  the  group  should  be  selected 
from  Carpenter's  original  list;    not  from  among  the  species  si; 
quently   referred  to  the  group  by  him.     The  shortness  of  the  Drills 
influenced   Carpenter  and   Dall   to  place  this  group   next   t«>   the 
Leptochitons,  but  there  is  probably  no  affinity  indicated   l>y   this 
character,    Trachydermon  being  phy  to  genetically  as  far  from  7. 
ffi  iton  as  Ischnoehiton  is. 

The  length  of  the  gill-row  is  so  variable  that  genera  cann« 
founded  upon  that  character  in  the  present  family.     In  the  species 
itllms   and   ruber   I    have    ascertained    the    gills    to    l>e    median, 
as  they  are  said   to   be    also    in    the    tcrobieukUvs    and    //» 
of  Midd.     In  the  other  species  which    I    have  examined,   or   upon 
which  data  are  available,  interstinrtii.-*.   0  the   irills 

extend  from  two-thirds  to  over  three-fourths  the  length  <»t'  th. 


68  IM  IIN<»<  IIIToN. 

It  is  therefore  obvious  that  n<>  separation  can   he   made  from    other 
suhueiiera  of  hchnochiton  on  this  character. 

Several  species  of  Trachydermon    liave  distinctly   spon_ 
like  tlinse  of    T"/tir>//*i.      This    structure    is    exceptional    in    7.W/M*- 
chiton  where  the  eavee  a-  a  rule,  aie  solid,  as  in   the  genus    Cluito- 
i.     The  fact  i>e  that  certain    forms  of  Trachyderinon, 

such   a<    T.  ruber,  form  a  partial  transition   from  hchnochiton  to 

•  /A/. 

From  ZVoMyrfermon,  Carpenter  has  sundered  a  few  species  hav- 
ing Kadsioiil  central  valves,  to  which  he  has  given  the  sectional 

name  Ti:  \<  H \n\  i»i \. 

Section   Trachydermon,  s.  sir. 

I.  CINEREU8  Linn.'.      PI.  <i,  figs.  25-31. 

Shell  oblong,  elevated,  the  dorsal  ridge  subangular.  Anterior 
valve  half-circular,  the  posterior  margin  decidedly  emarginate. 
Very  evenly  and  finely  sculptured  with  diamond-shaped  granules, 
which,  although  somewhat  irregular,  seem  to  be  formed  by  the 
<»l)li(jue  intersection  of  curved  incised  lines  radiating  in  two  direc- 
tions from  the  apex.  Intermediate  valves  having  precisely  the 
same  sculpture  upon  both  central  and  lateral  areas,  the  latter 
slightly  raised,  but  not  distinctly  separated  from  the  central  areas. 
The  posterior  margin  of  the  intermediate  valves  is  rather  produced 
or  beaked  in  the  middle.  Posterior  valve  decidedly  smaller  than 
the  anterior,  having  the  umbo  low,  inconspicuous,  and  somewhat 
anterior. 

Interior  whitish  or  brown-tinged;  sutural  plates  wide;  sinus 
narrow. 

Insertion  plates  nearly  smooth,  slightly  roughened  «nit>i«le. 
Number  of  slits  in  the  anterior  valve  9  or  10;  in  the  posterior 
valve  10  or  14J.  The  teeth  of  the  posterior  valve  are  rugose.  The 
intermediate  valves  have  a  single  slit  on  each  side. 

lor   varying  greatly,  the  most   common    pattern    being   a.-hcn 
thickly  mottled  and  blotched    with  olive  ;   others  are  a  li.irht    fleshy- 
oranire.  and  frequently  the  light  and  dark  patterns  are  combined  on 
;irioiis  valve-  of  one  individual. 

The    girdle    has   usually   alternating   light     and    dark     bars.       It 
1  with    minute  >e;il.-s   th«-  edge   having  a   fringe  of  delicate 
v  .-pines. 


II  No.   I  II  TON. 

r_'  ',  l.ivadtli  74  mill. 
Leii-th  IS.  luvadih  ID'  mill. 
liritlnh  mid  Scandinavian  iSV./x.  m//-//»  /"  /,».//•/,  •//.  XO///A  /o  /; 

/\  •  / 


Chiton  etfMTtffll  LlN*  N'at.    xii,  /rx/r  Hanky. 

Conch.    ]>.    17.-   -Low  i-:,    /«>nl.   .Joimi.    ii,    p.    9 
II  \NI.KY,  Hist.  r.i'il.  Moll,  ii,  |>.  -ID'J,  (.   .V\  f.  1,   (T.  ni'iryiifif' 
plate*.—  r.  Hinryhntln*    IV.N  \.\  M,    P.rit.   /ool.   iv,  p.   71.  t.   ::•;,  f.  2, 
and  of  MONT.,  Sown.,  IJ\  i:.  and  .1  1:1  i  1:1  IB,  Brft   (  kmch,  iii,  p.  2'Jl  , 
t.    56,  i'.  5j    P.    /.   S.    ISS'J,    p.    669.—  C.   marginatus   M; 
Moiuis,   Knuna  der  Kieler  Bucht,  ii,  t.  1,  f.  1-5.  —  Craspedoch'ln* 
ma  ryln.it  u«  SARS,  Moll.  Arct.  Norv.  ]>.  11"),  t.  20,  f.  16  ;  t.  2,  f.  L'.— 
Trachydermon    mt  try  hiatus   CPR.,    New   Eng.   Chitons,    p.   1 
Trachijdermon.  cinereus  CPR.  MS.  p.   15.  —  DAM.,  Proc.    I 
Mus.  1878,  p.  323.  —  NOT  Lepidopleurus  cinereus  SARS,  /.  r.,  t.  7.  t'. 
8.  —  Chiton,  circmnrulliitit.*  Hi;i:vi:,  Conch.  Icon.  t.  27,  f.  K 

This  species  may  be  known  by  the  evenly  shairreened  surtin-r. 
which  is  quite  different  from  other  North  Atlantic  Trachydermons. 
Tr.  dentiens  Gld.,  which  Jeffreys  considers  the  same  as  Hnereiift, 
differs  in  sculpture,  color,  and  the  shorter  form.  There  are  a  num- 
ber of  old  and  more  or  less  doubtful  synonyms,  such  as  Ch. 
fiiscatus  Brown,  111.  Conch.  G.  B.  p.  66,  t.  21,  f.  17  ;  and  Jeffreys 
quotes  also  cimex  Chemn.  and  cimicinus  Landt. 

Carpenter  seems  to  have  supposed  that  the  gills  of  this  species 
did  not  extend  forward  beyond  the  middle  of  the  foot,  but  I  have 
determined  by  the  examination  of  alcoholic  specimens,  one  of  which 
is  drawn  on  pi.  7,  fig.  57,  that  they  extend  nearly  to  the  head, 
being  composed  of  16  or  17  plumes  on  each  side.  They  are  also  so 
figured  by  Meyer  &  Mobius.  In  this  character,  cinereiu  di 
from  albus  and  ruber,  in  which  species  the  gills  are  median. 

Carpenter,  having  examined  the  type  of  C.  circumra/lnf 
writes  that  he  is  satisfied  that  it  is  merely  a  cinereus.     The  locality 
given  by  Reeve  is  no  doubt  wrong. 

Yar.  variegatus  Phil.     PI.  7,  figs.  58,  59,  60. 

Smaller,  with  triangular  sutural  laniinir.     Anterior  valve  having 
8  or  9,  posterior  valve  having  7  or  8  slits  in  the  insertion  plates. 
Length  8,  breadth  5,  alt.  3  mill. 

Mediterraii(  ^ 


70  I-<   IINnrnITOX. 


variegaku  run..,  Knum.  Moll.  Sicil.  i,  p.  107,  1836;  ii,  p. 
83,  t.  19,  f.  l:>.—  WKINKAUFF,  Conchyl.  des  Mittelm.  ii,  p.  4lL>.— 
I  —  i  i.,  Chit.  del  mare  di  Geneva,  Bull.  Mai.  Ital.  iii,  p.  7,  t.  1,  f.  1, 
1870.  —  Chiton  mnrginatus  Penn.,  TIBERI,  Bull.  Soc.  Mai.  Ital.  iii, 
p.  139,  154.  —  MONTEROSATO,  Enum.  e  Synon.  p.  16,  1878.  —  Brn., 
DAI  i/  iV  DOLLF.,  .M..11.  Mar.  Rouss.  i,  p.  497,  t.  61,  f.  13-Ki;  t. 
62,  : 

I  have  preferred  to  retain  the  Mediterranean  form  distinct,  at 
least  as  a  geographic  variety,  for  it  differs  from  Tr.  cinereus  of  the 
north  in  being  constantly  smaller,  having  fewer  slits  in  the  end 
valves,  and  having  the  sutural  plates  of  a  decidedly  different  shape. 

I.  Ai.r.rs  Limn'.     PI.  7,  figs.  35-38. 

Shell  oblong,  elevated,  the  back  keeled,  lateral  slopes  nearly 
straight.  Anterior  valve  half-circular,  its  posterior  margin  slightly 
concave  ;  sculpture  consisting  of  some  scarcely  perceptible,  low 
radiating  ridges,  often  wholly  obsolete,  and  an  excessively  minute 
shagreening  or  granulation  of  the  whole  surface,  the  granules 
showing  a  disposition  to  be  arranged  in  oblique  curved  lines. 
Intermediate  valves  slightly  beaked,  produced  forward  in  the  mid- 
dle, having  the  same  sculpture,  and  showing  low,  irregular  growth 
wrinkles.  Lateral  areas  scarcely  raised,  sculptured  like  the  front 
valve.  Posterior  valve  having  the  umbo  slightly  elevated,  central, 
inclined  backward. 

Interior  white.  Sutural  plates  large  and  wide,  extending  from 
the  insertion  plates  nearly  to  the  jugum.  Sinus  rounded. 

The  anterior  valve  has  13  slits  in  the  smooth  and  rather  sharp 
insertion  plate;  the  intermediate  valves  have  one  slit;  the  posterior 
valve  has  10  slits,  and  the  edge  of  the  plate  is  decidedly  roughened 
and  irregular.  Another  specimen  has  14  slits  in  the  anterior  valve, 
}'2  in  posterior  valve;  and  in  still  another  individual,  some  of  the 
intermediate  valves  have  two  slits  on  one  side. 

The  girdle  is  covered  with  small  gravelly  scales,  and  has  no 
marginal  fringe  of  long  scales  or  spines. 

The  gills  consist  of  thirteen  leaflets  on  each  side,  extending  for- 
ward two-  thirds  the  entire  length  of  the  foot. 

The  color  is  a  very  delicate  buff  tint,  sometimes  almost  white, 
often  shading  into  a  light  orange  on  the  posterior  part  and  lateral 
areas  of  each  valve.  Most  specimens  have  more  or  less  of  a  blark 
deposit  on  the  back  part  of  the  valves. 

Length  1."),  breadth  7  mill. 

Length  10,  breadth  5-6  mill. 


»CHNOCHIT< 


A  relic    <nnl     .\nrlli     At/anlir   Sects  ;     Grccn/n  n<l  ;     /r/7////// 
tn'i'i/rii  ;    Xnimlimn'iii  ;    />'/•//  /W/  n{  .}/,,,, 

S/.  Lawrence,  Maine,  and  south  to   Mauaehutettt   \ 

In    tlir    r,icifii-  from  Arctic   Ocean,  xo  /f///.  In  tin-  .S'/M/w//////    /..-.,   n'ent  to 
h'l/xkn.      Low  water  to  :!:;7  f'ms. 

Chiton  ulbii*  LINM:,  Syst.  Nat.  xii,  p.  1  107.-  Lowi:,  /•>«.].  .I.-urn. 
iii.  p.  SO.—  Sown.,  Conch.  III.  f.  !>'.),  UK).-  GOULD,  Inv.  Rfa 
loi).  f.  21.—  MlDD.,  Mai.  Ross,  i,  p.  120.—  I-'OKI:I.<  A-  HANI  i;v, 
I'.rit.  Moll,  ii,  p.  405,  t.  62,  f.  2.—  STIMPSON,  Sh.  of  N.  En#l.  p, 
inv.  of  (Jrand  Manan  p.  2'J.  —  .Ji:i'F.,  Brit.  Conch,  iii,  p.  L'-jn  ;  v.  p. 
199,  t.  56,  f.  3.—  BINNEY,  in  Gould's  Invert.  Mass.  p.  265,  i.  51 
?  Chiton  onjzn  S]-I:N,;IJ:K,  Skrift.  Nat.  Selsk.  iv,  hft.  1,  17'.»7,  teste 
JiflV.  —  Ch.  «selloides  LOWE,  Zool.  Journ.  ii,  p.  !().'»,  t.  ">,  f.  3.  — 
WOOD,  In<lcx  Test.,  Suppl.,  t.  1,  f.  9.  —  Ch.  sagrinatus  Connorv, 
Amer.  Journ.  Sci.  xxxiv,  p.  217,  1838;  Bost.  Journ.  ii,  p.  82.  — 
Lejttochiton  albus  H.  &  A.  AD.,  Gen.  Rec.  Moll,  i,  p.  473.  —  Chitmi 
(Lepidopleurus)  albus  JEFFREYS  Brit.  Conch,  iii,  p.  210.  —  Ch. 
(Lophyrus]  albus  JEFFR.  P.  Z.  S.  1882,  p.  669.  —  Lophyrus  fi/lm* 
SARS,  Moll.  Reg.  Arct.  Norv.  p.  114,  t.  8,  f.  2  (?  not  t.  I,  f.  9).— 
?  Ch.  minimus  GMEL.,  Syst.  Nat.  xiii,  p.  3205.  —  Trachydermon 
albas  CARPENTER,  New  Engl.  Chitons,  Bull.  Essex  Inst.  v.  p.  153; 
MS.  p.  15.—  DALL,  Proc.  U.  S.  Nat.  Mus.  1878,  p.  322. 

This  well  known  Arctic  and  subarctic  species  is  intermediate 
between  Tr.  cinereus  and  Tr.  ruber  in  sculpture.  The  granulation 
is  much  finer  than  in  the  former  of  these,  but  is  on  the  same  general 
plan. 

On  pi.  6,  figs.  32-34,  is  copied  a  Carpenterian  drawing  of  the 
interior  of  Tr.  albus.  It  is,  however,  incorrect,  the  form  of  head 
and  tail  valves  being  unusual,  and  the  slits  of  the  latter  entirely 
incorrect.  The  central  valve  is  well  represented  however.  The 
tail  valve  of  a  specimen  from  Grand  Manan,  drawn  by  the  writer, 
is  shown  in  fig.  38  of  plate  7,  correctly  delineating  the  slits. 

I.  EXARATUS  Sars.     PL  7,  figs.  39-49. 

Elongated,  oblong-elliptical,  strongly  convex  :  valves  distinctly 
obtusely  carinated  medially.  Anterior  valve  nearly  semicircular 
in  front;  the  posterior  edge  forming  an  obtuse  reentrant  angle, 
with  a  rounded  notch  in  the  middle;  surface  di.-tinrtly,  radially 
grooved  with  single  rows  of  rounded  granules  between  the  grooves, 
becoming  larger  toward  the  margin. 


,  '2  I»CIIN«)CHIT('N. 

Median  valves  are  moderately  wide,  nearly  straight  posteriorly, 
tin- hinder  ones  with  a  slight  median  beak  with  distinct  diagonal 
furrows  and  ridges,  dividing  them  into  median  and  lateral  areas; 
the  median  areas  are  covered,  on  the  sides,  with  fine  but  very 
distinct  longitudinal  grooves,  with  the  intervening  ridges  narrow 
and  rounded,  more  or  less  confluent  and  broken  up  into  granules, 
near  the  diagonal  lines  towards  the  median  ridge  becoming  finer  and 
irregular,  and  finely  granulous  anteriorly  and  along  the  carina. 
Tin-  lateral  areas  are  more  elevated  and  covered  with  stronger 
radiating  ridges,  broken  up  into  oblong  and  rounded,  flattened 
granules,  and  separated  by  narrow  radial  furrows.  The  lateral 
insert  ion-plates  of  the  median  valves  project  but  little  beyond  the 
upper  lamina;  they  are  sub-truncate,  with  a  thin  notch  or  slit  cor- 
responding to  the  diagonal  line  above.  The  posterior  valve  is 
transversely  elliptical,  with  the  posterior  edge  evenly  rounded  ;  the 
front  area  is  as  in  the  preceding  ones;  the  posterior  area  is  covered 
with  fine  radial  and  concentric  grooves,  dividing  it  into  radiating 
rows  of  small  rounded  granules;  the  articulating  plates  of  its  front 
edge  are  rather  wide,  broadly  rounded  or  sub-truncate,  and  separatee! 
l>v  a  broad,  rounded  median  sinus ;  posteriorly  the  inner  surface  is 
marked  by  about  sixteen  radiating  lines,  terminating  in  thin 
notches  of  the  inserted  edge,  which  is  very  narrow  and  simple. 

The  marginal  membrane  is  rather  narrow  and  covered  with 
rather  stout,  prominent,  oblong  and  obtuse  spinules,  regularly 
arranged  in  quincunx,  their  ends  looking  like  granules,  at  the 
edge  and  on  the  lower  side  these  are  replaced  by  small  slender 
spinules. 

Head  rounded ;  hood  large,  the  sides  produced  backward  into 
rounded  lobes.  Foot  long  and  rather  narrow.  Gills  about  twenty- 
four  on  each  side,  extending  from  the  posterior  end  of  the  foot  to 
about  its  anterior  third. 

Length,  17  mm.;  breadth,  8  mm.;  height,  5.5  mm.;  length  of  shell, 
1 .")..",  nun.;  breadth,  7  mm.;  length  1st  valve,  3  mm.;  breadth.  (5  mm.: 
]"ii_rth  .'Ird  valve,  exposed  part,  2  mm.;  breadth,  7  mm.,  length  of 
p  -terior  valve,  3.5  mm.;  breadth,  <!  mm.  (  }'crr!ll.) 

Xnrway;  Off  Martha's  Vineyard,  101-194  fms.;  off  /V/-//<///r//,/,/, 
Flo. 

/,<//,//_»//•//.<  r.nirntu*  SAKS,  Moll.  Keg.  Arct.  Norv.  p.  11.°),  t,  8,  f. 
1  ;  t.  II,  f.  1,  1*78. —  Trachydermon  exanihi.*  Sars.  VKKIIII.L.  Anier. 
Joom,  Bel  xxiv.  p.  :;i)f>,  1882;  Trans.  Conn.  Aead.  S-i.  vi,  p.  208, 


UN..,  Bin 


t.  :',(>,  f.2,  2a,2&.-    DM.  i,   Hull.  [  .  B,  Nai. 
f.  1'. 

This    species    is    readily    di>t  inurnMied     from      I  \      the 

very  di-tinct  differentiation  of  the  valves  into  median  and  in 

areas,   having  lines  of  sculpture  rniiiiin.Lr  in  diH'en-nt  direction-,  and 
by    (lie    much   coarser  granulation   of  their   Bdlfaoet,      In     I. 
there  are  no  distinct  lateral  area-;   the  radiatiirj  grooves  JIIM|  ridge* 
arc  absent  ;   and    the  granulation    is  >o  line   and    ub-mn-   a.-    ; 
scarcely   visible  without  a  lens.     Tlie  spinulation   of  the  mar: 
membrane  is  similar  in  the  two  species.     (  Verrill.) 

I.  DENTIKNS  (Jould.       PI.  8,  figS.    61-()~>. 

Shell  oval,  rather  elevated,  dorsally  angled,  ash  colored,  clon  -ly 
and  finely  mottled  with  olive,  and  having  a  series  of  alternat  in  ir 
olive  and  light  spots  upon  the  back  edges  of  the  valves  ah.ni:  the 
sutures.  These  spots  are  often  obscure  or  wanting,  and  in  some 
specimens  the  ground  color  is  a  pale  orange-flesh  tint. 

The  valves  are  covered  with  a  very  minute  sharp  granulation. 
the  granules  small  but  well  raised,  and  on  the  central  areas  of  some 
specimens  they  are  somewhat  disposed  to  be  arranged  in  longitud- 
inal lines  converging  toward  the  dorsal  ridge,  this  disposition  n-u- 
ally  stronger  toward  the  lateral  extremities  of  the  valves.  Tin- 
lateral  areas  are  a  little  raised,  the  diagonal  lines  separating  them 
from  the  central  areas  rather  distinct.  The  urn  bo  of  the  posterior 
valve  is  median,  somewhat  raised,  the  slope  behind  it  being 
depressed  and  concave. 

The  interior  is  either  whitish  stained  with  gray-green,  or  quite 
green.  The  sutural  plates  do  not  project  as  far  as  usual,  and  on 
some  valves  they  are  emarginate  in  front.  The  ju.iral  sinus  is  wide. 
angular,  flat  or  encroached  upon  by  the  jugum.  The  anterior 
valve  has  11  slits  in  the  insertion  plate,  the  intermediate  valves  1, 
the  posterior  valve  has  10  or  12,  and  some  of  the  median  teeth  are 
bifid  at  the  tip. 

The  girdle  is  narrow,  gravelly,  covered  with  minute  scales. 

The  gills  extend  to  the  front  end  of  the  foot. 

Length  15,  breadth  10  mill. 

Puget  Sound  (Old.)  ;  San  Diego,  California  (Hemphill,  in  A.  N. 
S.  P.  coll.). 

Chiton  dentiens  GOULD,  Proc.  Bost.  Soc.  N.  H.  ii.  p.  14">:  <>tiu 
p.  0.  —  eft.  (Onithochitoii)  dent  ten*  <ii.i>.,  /.  <•.,  LM'J  :  1".  S.  Kxpl. 


/4  WCHNOCHH 

Kxped.  p.  :i-_M.  t.  -I:::1.    had  .—  Trnchnd-r,  DAM..  Proc. 

U.  S.  Nat.  Mus.  1ST*,  j».  :\'i:\. —  '!',•< n-hydermon  pseudodentiens  CAR- 
RENTER,    r.rii.  &J8O.  Adv.  Sci.  Rep.  1863,  p.  (J4!»  :    Pn.c.  Acad. 
8cL  Phila.  !*»;:>,  p.  60. 

This  sj>ecies  is  closely  allied  to  chierens  L.,  luit  dillers  in  the 
sharper  granulation,  tlie  granules  being  less  regularly  arranged,  in 
the  tbrm  <>f  the-  sutural  plates  and  the  color  both  externally  and 
within.  The  girdle  of  dentiens  differs  from  that  of  cineren*  in 
lacking  the  marginal  spicules  characteristic  of  that  species.  The 
gills  are  long,  as  in  rhirreus. 

Gould's  diagnosis  and  figures  are  extremely  incorrect,  the  liiiht 
spots  alonir  the  sutures  having  been  mistaken  by  him  f«>r  projections. 
•  »r  "teeth,"  whence  the  name  (lcntirn*.  ( 'arj)enter  ascertained  tin- 
identity  of  dentiens  with  the  present  form  by  an  examination  of 
Gould's  type  specimen. 

A  series  from  San  Ignacio  Lagoon,  Lower  California,  differs  from 
the  San  Diego  shells  in  being  narrower,  chiefly  dark  green  (occa- 
sionally with  some  lighter  valves),  and  in  being  more  subtly  granu- 
lated. The  interior  is  vivid  dark  green.  One  of  these  is  shown  in 
fig.  65.  These  specimens  show  a  short,  slightly  acute  and  beaked 
umbo  on  the  central  valves.  In  the  larger  northern  specimens  this 
is  lost  by  erosion. 

nil < :irs  Carpenter.      Unfigured. 

Shell  small,  much  elevated,  green,  elegantly  tinted  with  rose  and 
olive;  valves  gothic-arched,  the  dorsal  ridge  acute;  lateral  areas 
small,  arcuately  distinctly  defined,  granulose;  umbones  prominent; 
umbonal  margin  having  a  tessellated  color  pattern  and  incurved. 
Central  areas  longitudinally  ribbed,  ribs  rounded,  close,  not  much 
elevated,  the  interstices  small,  sometimes  slightly  decussated.  End 
valves  sculptured  like  the  lateral  areas,  the  tail  valve  having  the 
umbo  median  and  somewhat  elevated. 

Interior  having  the  sutural  plates  scarcely  separated,  the  jugal 
sinus  very  broad  and  shallow;  insertion  plates  of  median  valvts 
having  a  single  slit,  terminal  plates  with  -s-10  slits;  the  plates  are 
obtuse;  eaves  hardly  elevated. 

(Jirdlemost   minutely   scaly,   the  granules   very  close,  rounded 
smooth;  edge  with  .-mail  suberect  hairs.     ((.'/ 

Length  5,  breadth  2A  mill.  ;  div.  80°. 

CataliiKi 


i-<  HNO  in  i 
(/nth!,-n.<  (  lABPl  WTEH  v.   Sci. 

p,  648;  Proc,  Cal,  &cad  8ri.  ill,  p.  212, 

An  unusual  character  in  ihi>  II,  prettil' 

ci.-  is  that   the  sutural    hmiin.-e  iitly    con; 

jiiLral  sinus]  l»y  a   layer  liniiiLr  tin-  very  bl 

'Indt'nfn'H*    [       dtntient  <lld.|  a  false  Mppeanmn-  0j 

given  t..  the  saturee  by  the  spot*  of  darker  painting.    (<)       j/s 

I-(     II.\«M     III   I   - 

I.  RETiPORoeus Carpenter,     UnfiguretiL 

Shell  small,  subelongate,  ashen  colored ;  mucln-lfvatcd,  u 
arcuate.     Vulvi's  sulxjuadratc,  apices  conct-alcd.  lateral  areas  litil.- 
defined, having  '•>  to  (>'  i-oun<lc(l,  obsolete  riblcts,  here  an.l  thm-  with 
acute  projecting  granules.     Central  areas  pitted  all  over.  ; 
small,  punctate.     Terminal  valves   with   more   acute  close  nai 
riMrts.      Mucro   little   raised,   anterior.      Inside   with  hroad  -utural 
sinus.     Insertion  plates  of  intermediate  valves  with  one  slit  on  each 
side,  terminal  valves  with  about  12  slits.     Girdle  bearing  dote, 
minute  scales,  which  are  little  elongated. 

Length  11,  breadth  7  mill.;  div.  90°. 

v 

Trachydermon  retiporosus  CPU.,  Brit.  Asso.  Rep.  1863,  p. 
Ischnochitoii  (Trachydermon}  retiporosus  CPR.,   Proc.    Aead. 
Sei.  1'hila.  1865,  p.  59. 

A  species  like  scrobiculatus  ]\Iidd.,  the  central  pattern   in  net- 
work, lateral  areas  with  3  to  6  ribs. 

Known  to  me  only  by  Carpenter's  description. 

I.  FLECTENS  Carpenter.      Unfigured. 

Shell   small,  subelongate,  roseate;  jugum  acute:    lateral    areas 
scarcely  defined.     Valve  margins  excurved,  sum  IT  incurved,  a] 
very  prominent;    valves  having  minute,   not    very  c  'Miles 

sparsely  suhradiatinir,  all    over   very    minutely    punctulate.      Mucro 
conspicuous,    anterior.      Inside:    sutural    sinus    wide,    Hat:    • 
seaivelv    projecting.       Terminal   valves    with    11.    median     1     slit. 
Girdle  very  minutely  granulate. 

Length  8f,  breadth  6  mill.:  div.  110°.     (Cpr.) 

*• 


76  IS.   IIN'H'HITON. 

2Y<  '     u.,  Rep.  Brit.  Asso.  Adv.  Sci.  1863,  p. 

—Inchnochiton  (Trachydermoii)  Jiectens  Cri:.,  1*100.  Acad.  >'at. 
Sci.  Phila.  1865,  p.  60. 

A  variety  i'rom  Catalina  Is.  has  the  posterior  valve  with  7,  inter- 
mediate 1 .  anterior  8  slits,  the  mucro  less  anterior  ;  divergence  90°. 
(Opr.) 

I.  LIVIDUI  Middendorff.     PI.  6,  figs.  22,  23,  24. 

Shell  elevated,  teL'inentum  smooth,  shining,  livid.  Anterior 
valve,  lateral  areas  and  posterior  valve  obsoletely  radiately  ril>- 
stiiate.  Central  areas  longitudinally  costulate,  the  riblets  sepa- 
rated, .-harply  cut,  whitish,  18-20  in  number.  Lateral  areas 
depressed.  (Jills  median. 

Length  23  mill.;  divergence  120°. 

Sitka. 

Chiton  (Stenosemus)  lividus  MIDD.,  Beitr.  zu  einer  Malac.  Ros- 
sica,  i,  p.  124,  t.  13,  f.  3,  4. 

This  species  and  the  next  have  not  been  found  by  later  observers. 

I.  SCROBICULATUS  Middendorff.     PI.  8,  figs.  66,  67,  68. 

Shell  depressed,  tegmentum  rough,  opaque,  ashen  or  yellow- 
brown.  Central  areas  regularly  pitted  in  longitudinal  series;  lat- 
eral areas  swollen,  divided  by  a  radiating  groove  which  widens 
below.  Girdle  having  narrow  scales.  Gills  median,  16  in  number. 

Length  9  mill.;  divergence  about  130°. 

California, 

Chiton  (Stenosemus)  scrobicnlatus  MIDD.,  Mai.  Ross,  i,  p.  127,  t. 
14.  i1.  4-7. 

I.  SOLIDIOR  Carpenter,  n.  sp.     Unfigured. 

Shell  small,  oval,  somewhat  elevated,  rather  flesh-colored;  jiifrum 
obtuse  ;  niuero  elevated,  in  front  of  the  middle.  Valves  pointed,  a 
little  rounded  at  the  margins;  lateral  areas  scarcely  defined. 
Entire  surface  smooth,  under  a  lens  minutely  roughened  and  very 
minutely  punctate  ;  wrinkles  of  growth  conspicuous. 

hind.-:  posterior  yalye  with  9,  anterior  with  -s,  median  with  1 
slit;  the  teeth  obtuse,  solid,  much  separated,  at  times  somewhat 
roughened.  Sinus  wide,  flat  ;  caves  *h<>rt. 

(iirdle  normal  I'm-  TrnrJiiidr,-ni»n,  the  granules  solid. 


II  \«  >•    Illl' 


This  is  the  only  tropical  Bpecief  th:it    I  have    met    with,   ami 

very  ;ii>n.)i-in:il  in  \\<  itumpy  projecting  teeth,  re0embliog  tbote  of 
Tnnif,-//ii.    The  girdle  IB,  however,  normal,  tin-  extremely  nil 

crowded    granules    present  ini:  :i  s«.me\\  hat  hri.-t  I  \   . 
the   mirroseopi'. 

The  above  is  taken  from  Carpenter's  Jtfft    Thety]  oen  is 

Miis.  (  'iiiiiin-,  N<».  !()/>. 


I.   \>IM:IM«>I:  Carpenter,  n.  sp.      I  'nfn/ured. 

Shell    small,  oval,  depressed,  the  juirnni    acute.       Valves    apicu- 
late;    ashen,   maculated    with    darker.       Mucro   rather   raided,   the 
posterior  slope   concave.      Kntire  surface   under  a    l<-n-  §een  ' 
conspicuously  j)iistulose  ;  central  areas  havinir  ahout    7  suhparalle] 
lines   of  small    but  projecting  granules,  bending  toward  tl:e  jiiiruin, 
closer  on  the  jugal  area.      Lateral   areas  hardly  elevated,   ha 
about  3   very  distant  and  a  little  larger  lines  of  granules;  anterior 
valve  with  about  18  such  lines. 

Interior:  anterior  valve  with  8,  central  valves  1,  posterior  valve 
with  9  slits;  teeth  acute,  long  ;  eaves  conspicuous,  short  ;  sinus  nar- 
row, deep,  laminated  but  scarcely  dentate.  Girdle  thickly  beset 
with  most  minute  purple  smooth  scales  (and  occasionally  corneous 
hairs,  perhaps  foreign  to  it). 

Length  1H,  breadth  7*  mill.  ;  div.  140°. 

Eaxt 

.'  Trochydermon  asperior  Cm.,  MS.  p.  19. 

The  solitary  specimen  was  found  in  a  mixed  group  of  species, 
named  C.  pulcherrimus  Sby.,  and  Lept.  craticulatus  by  Dr.  (iould, 
and  coming  from  either  Hong  Kong  or  Hakodadi.  It  will  be 
easily  recognized  by  its*  sculpture  and  minutely  chaffy  s<  ; 
Whether  it  belongs  to  this  genus  or  to  C/urtopleura  will  probably 
be  decided  by  the  gills.  (Cpr.) 

I.  PERORNATUS  Carpenter,  n.  sp.     Unfigured. 

Shell,  small,  subelongate,  elevated;  jugmn  acute;  ashen  or  olive 
maculated;  mucro  slightly  before  the  middle,  planat.-.  Central 
areas  with  subparallel  strong  tuberculate  bars,  about  H)  mi  each 
side,  interstices  decussated;  jtiLral  urea  granulate,  sculptured  in 
front;  lateral  areas  strongly  defined,  having  rounded  irregularly 
radiating  tubercles,  of  which  there  are  around  the  margin  of  the 
posterior  valve  about  20,  the  median  valves  f>,  anterior  val\> 


78  ISCHMK   I II  TON. 

Interior:  anterior  and  posterior  valves  having  7  slits,  median 
valves  1  slit ;  teeth  a  little  acute,  eaves  large,  pectinated  by  the 
t ul »ercles  or  little  bubbles  of  the  outer  .surface;  sinus  moderate, 
deep,  flat,  smooth. 

Girdle  closely  beset  with  rather  flat,  subpilose,  minute  scales. 

Lemrth  1">,  breadth  7-1  mill.;  div.  (.>">°. 

Habitat  >/?// 

Ttchydermon  perornatus  CPR.,  MS.  p.  19. 

Congeneric  with  asperior,  but  easily  distinguished  by  the  very 
>tr"i)Lr  sculpture,  flattened  mucro,  yet  sharp  elevation  of  the  .shell. 

'••) 

1.  VIRGATUS  Reeve.     PI.  8,  figs.  72,  73  (enlarged). 

Shell  oblong-ovate,  minute  ;  valves  smooth,  or  under  a  lens  very 
finely  reticulated;  beautifully  mottled  and  striped  with  bluish- 
green  and  yellow\  Ligament  very  minutely  scaly,  marbled.  (JRve.~) 

Port  Lincoln,  Australia. 

Ch.  virgatus  Rv.,  Conch.  Icon.  t.  28,  f.  192,  ISl&.—  Trachydermou 
virgatus  Rv.,  CARPENTER,  MS.  p.  22. — Ischnochiton  virgatus  Rv., 
CPR.,  MS.  p.  106. 

( 'arpenter  writes  as  follows  of  the  type  specimens :  Two  speci- 
mens, Mus.  Cuming;  minute,  length  5,  breadth  2  mill.;  div.  85°. 
Shell  very  arched,  the  jugum  rather  obtuse  but  not  very.  Mucro 
elevated,  the  posterior  slope  slightly  concave.  It  looks  externally 
like  the  young  of  lentiginosus,  being  painted  in  the  same  way- 
olivaceous  with  bluish-green  spots.  Girdle  tessellated  with 
*mnll  scales  not  striated;  granular.  The  three  areas  are  scarcely 
to  be  distinguished.  Very  conspicuously  quasi-granulate  all  over. 
The  juirular  part  is  partially  streaked  with  brown  in  one  specimen, 
blotched  with  ashen  in  the  other.  The  anterior  valve  has  D,  central 
valves  1,  posterior  valve  9  slits.  Teeth  sharp,  few,  long.  Eaves 
moderate.  Sinus  broad,  moderate,  flat,  not  channelled. 

I.  YIRESCENS  Reeve.     PL  8,  fiir<.  71,  75. 

Shell  ovate,  valves  smooth,  crenulated  along  the  posterior  edge  ; 
bright  pale  green  ;  ligament  horny.  (7?r.) 

JIahitaf  mil:/' 

Chiton  rh-escens  REEVE,  Conch.  Icon.  t.  L'o.  f.  j-ji;,  May.  1847.— 
"ft  Tro'-Inj.hnnon  n'rescena"  Cl'R.,  MS.  p.  21. 


i!  Norn  I  !  . 

( larpenter'e  aotei  are  as  toll.,- 

CiiiniiiL'-.     A   very  remarkable  ipecies,  \\iili  M 
combination  of  characters.     IVrhap-  it  belong-  rather  win 

etO,       Valves  rather    pointed    in    limit,    and    broader    behind  ; 
oval,    -omewhat  elevated,  jiiguni  rat  her  .-ha  rp.      (in-ni,  uitli  one  OF 
more    valves    always    varie-ated    with    darker;    line    N's.-dlati..; 
suture-,    causing    it     to    appear    toothed.      Muero    rather    rai- • 
anterior  third  ;  posterior  >h>pe  very  concave.    Valves  rath'  ; 
with  conspicuous,  rat  her  obtuse  apices.     Side  areas  scared  v  di-tinct. 
'The   whole   surface   is  rat  her  glossy,  hut  under  the  niirrosropr  uitli 
extremely    line    .irranulation,    which    runs    into    line  lines  alon-  ami 
near  the  juiruni.     ( Jirdle  Trachydermoid,   covered    with    extremely 
minute  scales  and  occasional  hairlets,  but  at  the  sutures  and    in    a 
row   around  the   margin   are  a  series  of  brown  dots  which  turn  out 
to  be  semi-pores,  quite  regular  but  without  hairs,  only  lar.Lri 
making  a  kind  of  knob.     They  are  very  conspicuous  as  pore-lumps 
when  the  shell  has  been  soaked.     The  anterior  valve  has  11,  central 
1,  posterior  9  slits.     Teeth  stumpy,  like  nuttallii,  but  not  striated. 
Sinus  shallow  and   rounded,  with  about  16  teeth,  formed  by  the 
lirations  of  the  anterior  part  within.     Eaves  short  and  very  spongy. 
Length  12-1,  breadth  7  mill.;  divergence  113°. 

I.  STRAMINEUS  Sowerby.     PI.  8,  fig.  71. 

Shell  ovate,  smooth,  pale  straw-colored  ;  back  rounded  ;  marginal 
scales  sparse.  (Sowb.~)  Length  10,  breadth  6  mill. 

Island  of  Chiloe,  under  stones  at  low  w 

Chiton  stramineus  Sows.,  P.  Z.  S.  1832,  p.  104  ;  Conchol.  Illustr. 
f.  28;  Zool.  Beechey's  Voyage,  p.  150,  t.  41,  f.  13.—  Trachydermon 
straminens  Sowb.,  CARPENTER,  MS.  p.  21. 

Carpenter  remarks :  A  distinct  species.    Five  specimens  in  Mus. 
(aiming,  much  worn  and  smashed.     They  scarcely  show  the  sculpt- 
ure ;  in  the  best  there  is  an  attempt  at  granulation.     Rather  broad, 
flat,  rounded  jugum.      Girdle  gravelly;    mucro   median,    a    tritle 
raised  ;  posterior  slope  nearly  straight.     The  anterior  valve  h:i- 
median  1,  posterior  10  slits;  teeth  sharp,  Isehnoid  ;  eaves  mod, 
Length  1H,  breadth  7  mill.;    divergence  about   114°,  the  valve- 
rounded. 


80  [SCHNOCHITON, 

I.  PUSILLUS  Sowerby.     PI.  8,  figs.  69,  TO. 

Shell  small,  obovate,  whitish  ;  back  elevated  :  intermediate  valves 
narrow,  very  minutely  punetulate  :  lateral  areas  somewhat  distinct  ; 
posterior  valve  larger,  the  apex  central,  inclined  backward.  (Sowb.) 

Length  6i,  breadth  lM  mill. 

Hirnminnio,  J'fi'ii,  on  a  coral  reef  in  17  fins.,  0  miles  from  shore. 

C.  ;>M.</////X  Sows.,  P.  Z.  S.  1832,  p.  57  ;  Conch.  Illustr.  f.  31.— 
RKI.VE,  Conch.  Icon.  f.  189. 

( 'arpenter's  notes  on  the  two  specimens  in  the  Cumingian  collec- 
tion are  as  follows:  Length  5J,  breadth  2-1  mill.;  divergence  90°, 
nearly  semicircular.  Small,  whitish-ashen,  long,  arched.  No 
jugum  or  jugal  area.  Lateral  areas  slightly  swollen  ;  granulated, 
but  no  other  pattern.  Mucro  rather  elevated,  posterior  slope  very 
concave.  Posterior  valve  with  11,  median  1,  anterior  10  .-lit.-. 
Teeth  sharp,  long  and  very  thin;  eaves  conspicuous,  not  spongv. 
Sinus  deep,  broad,  flat,  not  channelled.  The  shell  might  pass  in 
sculpture  for  a  young  punctulatissimus ;  in  shape  and  size  for  Lep- 
tockiton  cancellatus ;  but  as  far  as  I  can  see  the  girdle  scales,  they 
are  very  minute  and  like  Trachydermon,  but  they  have  mostly  per- 
ished, and  the  specimens  have  been  rather  smashed  and  are  in  bad 
condition. 

I.  1:1  I:I:K  Limit'.     PI.  7,  figs,  50-56. 

Shell  oblong,  elevated,  solid,  the  back  roundly  subangular,  lat- 
eral slopes  somewhat  convex ;  surface  apparently  smooth  except 
for  well-marked  grooves  or  wrinkles,  indicating  growth-periods, 
lender  the  microscope,  however,  an  excessively  fine  reticulation  is 
visible.  The  color  is  light  buff,  marbled  all  over  with  orange-red 
in  various  patterns,  or  entirely  suffused  with  reddish  ;  usually  hav- 
ing a  red  dorsal  stripe  bordered  on  each  side  with  buff. 

The  anterior  valve  is  twice  as  wide  as  long,  crescentic  rather 
than  half-round.  The  intermediate  valves  are  slightly  beaked, 
their  lateral  areas  slightly  raised  and  having  stronger  concentric 
wrinkles  than  the  central  areas.  Posterior  valve  having  a  rather 
elevated  but  obtuse  median  umbo. 

The  interior  is  briyht  pink.     The  sutural  plates  are  wide,  large  ; 
tlirjnyil  *in us  is  deep,  narrow  and  anf/nfur.     The  insertion  plate  of 
the  anterior  valve  has  8  to  11  slits;  intermediate  valves  normally  1 
-lit:  posterior  Yalve  7  to  11  slits.     The  insertion   plates  are  sharp 
and  smooth. 


DM   ll\n<   IN  I 
The    nil-die    U    reddish-brown.    eoveivd    with     minute    elon-at.  'I 


The  gills  extend  I'onvard  to  tin-  middle  of  tin-  body. 

Lciiirth  20,    breadth    12    mill.       Al:i.-k:m    BpeCUE 
Ii  iiLi'th  of  an  inch. 

Arctic  <IH<!  north*  rn  xeas  of  Europe;  south  t<>  M 

\.  1'iiciiir  <in<l  Ilt'i-hiy*  Sea  from   I'rih  iloff  Is.  went  to  Alia,  xoittlt  to 
N/7/-</  ;   l\nmrhntk<t.     Low  water  to  80  fins. 

Chiton  nihrr  L.,  S\>t.  Nat.  xii,  j>.  1  1  <»7.—  L»>\\  i:,  Zool.  Journ.  ii. 
p.  101,  t.  5,  f.  2.—  (Jon,  i),  Invert.  Mass.  p.  1  111,  f.  '_'  1  :  edit.  IJiimey 
p.  1M50,  f.  523.—  FORHKS&  HANI.KY,  IIi>t.  Mull.  (i.  I;,  ii,  ; 
59,  f.  6;  t.  AA,  f.  6.—  HANLKY,  Sh.  ,,f  Linn.  p.  17.  SoWEBBTj 
Coiu-h.  Illnstr.  f.  103,  104.—  RKKVE,  Conch.  Icon.  f.  175.—  JEF- 
i  IM.YS,  Brit.  Conch,  iii,  p.  224  ;  v,  p.  19!),  t.  M>,  f.  4.  —  Ch.  cinereus 
(  ).  F.vi;u.,  I-'uiin.  Clronl.  p.  423,  not  of  authors  nor  of  Lin  IK'.  —  Ch. 
minimum  SIM-:N<JL.,  not  of  Gmel.  —  Ch.  fan's  L<>VI;N,  Ind.  M.dl.  lit. 
Scand.  p.  28,  1846,  not  of  Mont.,  Forbes  &  Hanley,  et  al.—  Ch. 
Ar/'/'x  I'KNNANT  (probably),  Brit.  Zool.  (iv),  iv,  p.  72,  t.  :U\,  f.  3.— 
Ch.  latus  LEACH,  Moll.  Brit.  p.  231.  —  Chiton  (Lepidopleurus^ruber 
JEFFKKYS,  ]>iit.  ^Toll.  iii,  p.  210.  —  Trachydermon  ruber  CAi:ri;.\i  i  .1:. 
Bull.  Essex  Inst.  v,  p.  153,  1873.  —  Boreouhiton  ruber  SARS,  M«»ll. 
Reg.  Arct.  Norv.,  p.  116,  t.  8,  f.  4.—  TV.  ruber  DALL,  Proc.  V  - 
Nat.  Mus.  1878,  p.  320  (1879).—  Chiton  incarnatus  REEVE,  Conch. 
Icon.  f.  194,  1848. 

The  shell  is  apparently  smooth,  as  described  by  Forbes  and  Ilan- 
ley,  but  under  a  high  power  appears  finely  reticulated  as  observed 
by  Jeffreys.  Its  color  is  very  variable,  being  usually  marbled  red 
and  whitish  like  Tonicella  marmorea,  but  the  valves  may  be  uni- 
form dark  red  or  nearly  pure  white.  I  have  one  specimen  with 
the  four  central  valves  dark  red  and  the  rest  white  ;  one  valve  in  a 
specimen  is  often  dark  red,  while  all  the  others  are  marbled.  It  is 
most  likely  to  be  confounded  with  Tonicella  marmorea  and  - 
varieties  of  T.  liueata,  both  of  which  have  leathery  girdles,  while 
this  species  can  almost  always  be  determined  by  its  farina' 
girdle,  dusted  with  alternate  red  and  whitish  patches,  the  latter 
nearly  opposite  the  sutures.  (Dall.} 

I.  PUNICEUS  Couthouy.     PL  8,  figs.  76,  77. 

Shell  small,  thin,  elongated,  elliptical,  elevated  and  sharply  ear- 
iiuited  along  the  back,  of  a  dull  rose,  or  bright  brick-red  color,  and 
6 


ISCIINorliri' 

everywhere  minutely  punctured.  The  lateral  areas  are  vn-y 
abruptly  and  distinctly  elevated,  regularly  ridged  by  the  obtusely 
rounded  stages  of  growth  and  bearing  a  lew  scattered  granules. 
Central  areas  with  the  lines  of  increase  well  marked,  and  remark- 
ably barred  with  about  six  elevated,  longitudinal,  parallel  ridges, 
which  are  generally  dislocated  about  the  middle  by  some  of  the 
lin.-s  of  increa-r.  The  posterior  valve  has  a  very  minute,  and 
acute,  nearly  central  nmbo,  with  an  abrupt  depression  pas-im: 
transversely  through  it;  the  margin  is  very  minutely  imbri- 
cated by  prismatic  scales,  colored  like  the  shell,  and  with  yellowish 
band-  ending  it,  opposite  to  the  junctures  of  the  valves.  (G/c?.) 
Length  12$,  breadth  7'.  mill. 

Orange  Harbor,  Terra  del  Fuego. 

Ch.  j>n,i!rrns  (CouTHOUY  MS.)  GOULD,  Proc.  Bost.  Soc.  N.  11.  ii, 
1846,  p.  I-}-0.:  Exped.  Sh.  p.  5;  U.S.  Expl.  Kxped.  Moll.  p.  .°>24,  t. 
L'7.  f.  412;  Otia  Conch,  p.  5. —  Trachydermon  ruber  var.,  CAKI-I  N- 
TER  MS. — Lepidopleurus  puniceus  ROCHEBR.,  Miss.  Sci.  Cap  Horn, 
Moll.  p.  140. 

The  gills  extend  forward  to  the  middle  of  the  foot.  They  are 
erroneously  represented  upon  Gould's  plate.  Carpenter  considered 
this  a  synonym  of  T.  ruber,  but  it  is  probably  distinct. 

I.  STKINKMI  Pfeffer.     PL  6,  figs.  19,  20,  21. 

The  form  of  the  animal  is  a  somewhat  elongated  oval,  bluntly 
rounded  before  and  behind,  the  middle  keel-like  and  elevated. 
( Jirdle  covered  with  granules  which  are  somewhat  elongated  in  a 
radial  direction.  Eighteen  gills  on  each  side,  reaching  from  the 
middle  of  the  foot  nearly  to  the  posterior  end. 

Shell  rather  elevated,  very  finely  granulated.  Median  valves 
comparatively  narrow,  their  length  not  much  over  1  of  their 
breadth,  the  posterior  angles  not  produced  backward;  yo: 
examples  having  strong,  acute  apices,  older  having  less  projecting 
blunt  apices.  Lateral  areas  separated  from  central  ana-  by  a  dis- 
tinct ridge.  Central  areas  having  transverse  lines  of  fine  grains, 
which  turn  at  right  angles  and  become  longitudinal  on  the  lateral 
areas;  there  are  also  more  or  less  terrace-like  marks  of  growth- 
arrest.  There  is  a  system  of  weak  radial  wrinkle-stri;e,  converging 
toward  the  timbo.  upon  the  central  areas,  more  developed  in  young 
specimens,  and  totally  absent  in  the  larger  ones.  Anterior  valve 
half-round,  concentrically  finely  granulated,  and  having  coarse  con- 


ft  HWO  in  i 

erntrir    growth-mark-.        Tail     valve    hall'eimilar.    || 
-eulptiired    likr    the    head    valve;     it-    mitral    area  from 

than  .'   die  length  «.f  die  posterior  slope.     I'mbo  aeut»- 
examples. 

The  insertion  plates  are  nil  overhung  l»y  the  eaves,  th<    Ia1 
jectiDg  beyond  them.      Tin-  ;uit<  -rii.r   valve    has    17,    posterior   valve 
\'2  teeth. 

The  ground  color  of  the  shell  baa  a  light  reddish-white  or  hril- 
liant  red  tone,  with  more  or  less  distinct  radiating  flamed  <tn-ak8  of 
li-'hter  and  darker;  girdle  yello\visli-l>ro\vii,  lighter  toward  the 
edge,  with  i'cw  or  numerous  transverse  tracts  of  lighter.  / 

L.-ngth  2b",  breadth  14  mill. 

South 


steinenii  PFFR.,  ^Foll.  von  Siid-Georgien,  in  .Juhrb. 
Hand).  Wiss.  Anstaltcn,  iii,  p.  103,  t.  3,  f.  1,  1886. 

Closely  allied  to  T.  puniceus,  but  different  in  having  the  central 
and  lateral  areas  equally  granulated,  and  the  central  area  entirely 
without  longitudinal  sculpture. 

Section  Trachyradsia  Carpenter. 

Trachyradsia  CPR.,  MS.  —  DALL,  Proc.  U.  S.  Nat.  Mus.,  Jan., 
1878,  p.  \,  323.  Type,  C/i.  fulgelrum  Keeve. 

Chitons  like  Trachydermon  except  that  the  insertion  plates  of  the 
median  valves  have  two  or  several  slits. 

The  species  of  this  group  should  be  carefully  compared  with 
CalMntnn.  and  Stereochiton,  with  which  groups  they  agree  in  the 
multiple  slits  of  the  central  valves  and  the  markedly  spongy  ea 

I  am  not  disposed  to  group  these  forms  with  Trathydermon  but 
leave  them  here  in  deference  to  the  views  of  Carpenter.  It  should 
be  noted  that  Carpenter  did  not  consider  Ch.  fulgetrutn  the  tvpe  of 
his  group,  that  species  having  been  selected  by  Dull. 

I.  PULQETBUM  Reeve.     PL  8,  figs.  80,  81,  82. 

Shell  ovate,  a  little  attenuated  in  front,  very  minutely  and  doe 
decussately    punctured    under    the    lens,    throughout.      Terminal 
valves  and  lateral   areas  of  the  rest  somewhat  ohscmvly  radiatrly 
grooved.     Reddish-brown,  peculiarly  painted  with  longitudinal  yel- 
low and  black  zigzag  waves.     Girdle  horny,     (five.) 

H'thltat  tail;/ 


s  I  ISCHNOCHITON. 

Chiton  fulyetrum  ]Ji:i:vi:,  Conch.  Icon.  t.  xiii,  f.  71,  March,  1847. 
— /  Ti'itchijrmlt'm  fulgetriim  CPR.,  MS.  p.  24. — ?  Chiton  dental  us, 
SPENGLER,  Skrivter  af  Naturhistorie-Selskabet,  iv,  p.  88,  t.  6,  f.  16, 
Kiobonhavii,  17(.'7. 

Carpenter  writes  as  follows  of  the  type  specimen,  unique  in  the 
Cuming  Collection  :  The  mucro  is  prominent  and  median,  the  slope 
In-hind  it  very  concave.  The  interior  is  vivid  rose  color. 

The  insertion  plate  of  the  front  valve  has  20  slits,  median  valves 
4  to  5,  and  posterior  valve  18  slits.  Sinus  small,  imperfect  in  each 
valve,  but  probably  as  shown  in  fig.  81.  Eaves  small. 

Girdle  thin,  wide,  ornamented  with  small,  scarcely  imbricating, 
slightly  elongated,  very  close,  deciduous  scales. 

Length  63,  breadth  38  mill.;  divergence  103°. 

The  scales  are  extremely  minute  deciduous,  crowded  into  an 
irregular  spongy  mass,  and  when  seen  separately  are  not  like  a  flat 
spine  as  in  Callochiton,  but  somewhat  rectangular  and  scarcely 
elongate.  They  have  perished  over  most  of  the  specimen,  although 
that  is  in  fine  condition.  It  appears  to  have  been  tessellated  with 
white  over  the  chestnut  surface  but  most  of  the  specimen  is  now  of 
a  light  horn  color.  The  radsioid  character  of  the  valves  and  the 
brilliant  rose  interior  makes  this  specimen  very  like  castaneus  but  it 
is  known  outside  by  the  obsolete  riblets  formed  by  slight  depressions 
co-ordinate  with  the  slits  inside.  Even  these  do  not  appear  in  the 
younger  part  of  the  shell.  The  color  markings  are  probably  vari- 
able. It  is  probably  from  S.  Africa.  (Q?r.) 

I.  ALEUTICUS  Ball.     Unfigured. 

Shell  small,  rufous-ashen,  oblong,  vaulted,  the  jugum  very  acute; 
mucro  submedian  ;  apices  prominent ;  lateral  areas  inconspicuous, 
entire  surface  minutely  reticulated  in  quincuncial  pattern. 

Interior:  anterior  valve  with  16,  central  with  2,  posterior  with 
11  slits;  teeth  small,  very  spongy,  widely  separated  ;  eaves  spongy, 
sinus  small.  <  Jirdle  beset  with  minute  scales.  (Dall.) 

Length  ('.,  width  3  mill. 

Kyska  Harbor,  Kyska  Id. ;  Constantine  and  Kiriloff  Harbors, 
Amchitka  Id.,  and  Nazan  Bay,  Atka,  in  the  western  Aleutians,  at 
low- water  mark,  under  stones  on  the  beach. 

Trachyradsia  aleutica  BALL,  Proc.  U.  S.  Nat.  Mus.  p.  1,  Jan., 
1878  and  t.  c.,  p.  323. 


1  1\«.  ••nirow.  85 

This  modest  little  species  is  of  a  dull  livid  purplish  red,    with    an 

aahy  tinge,  especially  on  the  narrow  girdle,     Kxcepi  r,,r  th<-  weii- 

marked  ridges  of  growth,  it  appears  SIIMM.||I,  hut  pOWeMet  '  like  all 
Chitons)  a  fiiu>  reticulation,  only  vi>iblc  under  a.  maLMiit, 
lateral  areas  are  not  distinct,  the  back  is  very  much  rounded  and 
the  valves  well  hooked  in  the  median  line.  The  substance  of  the 
valves  from  within  appears  remarkably  spongy  as  if  rotten,  or 
even  like  vesicular  pumice,  especially  under  the  eaves.  The  ante- 
rior slits  are  marked  by  radiating  lines  of  holes,  though  the  teeth 
between  them  can  hardly  be  made  out.  The  posterior  valve,  how- 
ever, has  not  this  aid  to  counting,  and  in  the  general  spongiin 
is  almost  impossible  to  say  how  many  teeth  or  denticles  exist.  It 
bears  no  marked  resemblance  to  any  other  species  of  the  region. 
(DalQ 

I.  MULTIDENTATUS  Carpenter,  n.  sp.     Unfigured. 

Shell  small,  reddish-ashen,  oblong,  vaulted,  the  jugum  very 
obtuse  ;  umbo  of  the  last  valve  submedian  ;  apices  prominent. 
Entire  surface  having  the  appearance  of  being  minutely  scaled  in 
quincunx  ;  lateral  areas  scarcely  distinguishable. 

Interior  having  20  slits  in  the  posterior  valve,  2  or  three  in  the 
intermediate  valves  ;  teeth  small,  solid,  obtuse,  deeply  and  broadly 
separated  ;  eaves  short,  spongy  ;  sinus  small,  very  wide,  scarcely 
laminate.  Girdle  beset  with  minute  scales.  (  Cpr.~) 

Bonin  Islands  (Stimpson). 

Trachyradsia  multidentata  CARPENTER,  MS.  p.  24. 

The  type  is  in  the  Smithsonian  collection. 

The  only  specimen  known  has  lost  its  head  valve,  and  most  of  the 
mantle  scales;  what  remain  of  these,  however,  are  of  the  Trac/u/- 
dermon  rather  than  the  Callochiton  type.  The  shell  was  named 
Lepidopleurus  lepidus  by  Dr.  Gould,  but  has  little  in  common  with 
that  species.  There  is  no  character  to  distinguish  it  by  outside  ; 
but  within  the  incisors  are  represented  by  a  series  of  roundish, 
stumpy,  peg-shaped  denticles,  set  rather  widely  apart  in  the  short 
spongy  gums  that  are  characteristic  of  Callochiton.  The  three  or 
four  lobes  in  the  side  valves  are  rather  longer. 


I.  LINDHOLMI  Schrenck.     PI.  27,  figs.  35,  36,  37,  38,  39. 

Shell  ovate,  about  twice  as  long  as  wide,  depressed  ;   olive-green, 
the   eroded   umbones  rosy-white.      Lateral  areas  and  end   valves 


86  I-i  'UNIX   IIIToN. 

racliately  costulate,  decussated  by  concentric  growth  sulci,  the  rib- 
It  -ts  more  or  less  scaly-gran  ose,  the  interstices  very  delicately  punc- 
tate. Central  areas  longitudinally  wrinkled,  the  interstices  deli- 
cately punctate.  Mucro  sulx-entral.  Anterior  valve  having  16, 
median  valves  4,  posterior  valve  12  slits.  Sutural  plates  yellowisli- 
rose  color.  Girdle  half  as  broad  as  the  lateral  slope  of  the  valves, 
very  delicately  granulose,  blackish-green  maculated  with  white. 
Gills  ambient,  composed  of  44  branchue. 
Length  44  mill.  ;  divergence  130°. 

Bay  of  Hakodadi, 


Chiton    lindJiolmi  SCHRENCK,   Bull.   1'Akad.   Imp.   Sci.   de  St. 
rsb.  v.  p.  511  ;  Melanges  Biolog.  iv,  p.  253;  Reiseu  u.  Forsch. 
im  Amurlande  ii,  Zool.  p.  288,  t.  12,  f.  9-16. 

This  large  radsioid  species  may  prove  to  be  a  Stenoradsia  (see  p. 
61)  ;  but  the  meagre  description  of  the  girdle  given  by  Schrenck, 
causes  me  to  place  it,  for  the  present,  in  the  decidedly  heterogenous 
group  Trachyradsia.  « 

Subgenus  VI.    ISCHNOCHITON  Gray  (restricted). 

Ischnochiton  GRAY,  P.  Z.  S.  1847,  p.  126.  —  SHUTTLEWORTH, 
Bern.  Mittheil.  1853,  p.  66.  —  Lepidopleurus  (part)  H.  &  A.  ADAMS, 
and  CARPENTER,  olim.,  not  Lepidopleurus  Risso.  —  Ichsnochiton 
FISCHKK,  Manuel  p.  880. 

Valves  having   sharp,   non-pectinated   insertion    plates  ;    mucro 
median  or  anterior;  girdle  covered  with  imbricating  scales. 
Within  this  subgenus  three  subdivisions  may  be  recognized  : 

Section  Ischnochiton  s.  s.,  in  which  the  valves  and  insertion  plates 
are  thin  and  smooth,  one  side-slit  in  each  median  valve  ;  the 
scales  of  the  girdle  flat  and  striated. 

Section  Lepidozona,  differing  in  the  convex,  solid  girdle  scale-. 
which  are  usually  almost  smooth. 

Section  Radsiella,  like  typical  Ischnochiton  except  that  there  are 
two  or  several  side-slits  in  each  median  valve. 

The  .-nbgenus  Heterozona  should  properly  be  included  here  also, 
and  Ischnoradtio  is  not  far  removed  from  Lepidozonn  in  characters. 


BOTO  in  i' 

.W///or///V 
(1.)     (I'nmj,  of    I.  /oiif/ininih'i. 

(  )l)h>iiM  -.^peril's,  with  line,  not  conspicuous,  sculpture,    tin-    central 


irranulatcd    in    quincunx    <>r    in    /iir/ai:    patt'-rn,    lateral    areas 
radially  ribbed. 

The  species  are  from  A  us(  ralo-/elandie  seas. 

I.  LONQICYMBA  (,>uoy  iV  (laimard.     PI.  22,  figs.  f>> 

Shell  oblong,  rather  highly  and  broadly  arched,  not  in  the  least 
carinated.  Surface  to  the  naked  eye  appearing  smooth  on  the  cen- 
tral, radiately  lirulate  on  the  lateral  areas  and  end  valves.  Color 
extremely  variable,  usually  pale  olive  mottled  with  dark  olive  or 
purple-black,  or  having  a  broad  light  band  along  the  back. 

Lateral  areas  distinctly  raised,  sculptured  with  8-12  radiating 
riblets,  often  bifurcating,  the  intervals  densely  granulated  ;  the  rib- 
lets  are  interrupted  by  irregular  impressed  concentric  growth-line-. 
Central  areas  very  closely  and  finely  granulated  in  quincuncial 
pattern  ;  the  granulation  is  nearly  even  on  the  jugum,  although  the 
anteriorly  divergent  rows  of  granules  are  sometimes  slightly  more 
prominent  ;  on  the  slope  between  central  and  lateral  areas,  and  <>n 
the  extreme  sides  of  the  latter  the  granules  are  arranged  to  form 
more  or  less  distinct  longitudinal  rows.  The  end  valves  are  verv 
minutely  granulated  and  radially  lirulate.  Umbo  of  posterior 
valve  rather  low,  obtuse;  posterior  slope  visibly  concave. 

Interior  green  or  blue  sometimes  varied  with  red  or  corneous. 
Anterior  valve  with  9-12,  central  1,  posterior  valve  11  slits;  teeth 
thin,  sharp  and  smooth  ;  posterior  tooth  of  the  side  insertion  plates 
short,  and  terminating  abruptly  before  attaining  the  posterior  mar- 
gin of  the  valve  (figs.  61,  64)  ;  eaves  solid. 

Girdle  closely  covered  with  solid,  convex  but  somewhat  flattened 
imbricating  scales,  most  of  which  are  rather  weakly  striated,  but 
among  which  non-striated  scales  are  mingled  (pi.  22,  figs.  63,  66). 

Length  33,  breadth  16  mill,  (often  smaller). 

New  Zealand:  Auckland  to  Duned  in  ;  Pitts'  Island;  Auckland 
Is.;  Campbell  Id. 

C.  longicymba  (?  Dufresne,  Mus.  Paris;  Blainville.  Diet,  des  Sri. 
Nat.  xxxvi,  p.  542),  Qn»y  A-  <  IAIMAMD,  Yoy.  de  PAstrol.  Xool.  iii, 
p.  390,  t.  75,  f.  1-18  (1834).—  Hi  EVE,  Conch,  [con.  t.  !'.»,  f.  126,  t. 
L'4,  f.  163d.  —  Lepidopleurus  lonyiciimbtm  Hni<>\.  Man.  N.  /. 
Moll.  p.  113(1880). 


88  ISCHNOCHITON. 

There  is  no  certainty  in  the  identification  of  de  Blainville's  lovgi- 
cymba  but  I  have  accepted  the  form  recognized  under  that  name  by 
(v)iioy,  as  he  was  the  first  to  figure  the  species.  This  identification 
coin  pels  us  to  regard  the  New  Zealarfd  shell  as  the  type  form.  Figures 
58,  60-66  represent  New  Zealand  specimens  furnished  me  by  Prof. 
Hutton  and  Mr.  G.  W.  Wright.  These  differ  from  the  Australian 
form,  which  I  have  named  Haddoni,  in  the  much  less  distinct,  less 
regular  striation  of  the  girdle  scales,  the  broadly  rounded  arch  of 
the  back,  and  the  short,  abruptly  terminating  posterior  tooth  of  the 
side  insertion  plates. 

I.  HADDONI  Pilsbry,  n.  sp.     PL  22,  figs.  67-73. 

Shell  distinctly  keeled  on  the  back;  scales  of  the  girdle  beauti- 
fully regular  in  size  and  arrangement,  and  evenly  and  deeply  grooved 
(fig.  67).  Sculpture  and  color  patterns  like  /.  longicymba. 

Interior  white,  greenish  or  bluish  ;  anterior  valve  with  10,  cen- 
tral 1,  posterior  valve  12  slits;  teeth  thin,  sharp.  Posterior  tooth 
of  the  intermediate  valves  long,  extending  almost  to  the  posterior-lat- 
eral angle  of  the  valve,  and  not  terminating  abruptly  (fig.  72). 

Length  27,  breadth  12  mill. 

The  coloring  is  even  more  variable  than  in  the  New  Zealandic 
/.  longicymba ;  some  specimens  are  clear,  light  greenish-buff  (fig. 
71)  ;  some  are  brown,  speckled  all  over  with  olive-black  ;  some  are 
mainly  red,  or  black,  having  a  wide  white  dorsal  stripe. 

Port  Jackson,  Australia. 

Chiton  longicymba  So  WEBBY,  Conchol.  Illustr.  f.  67. — REEVE, 
Conch.  Icon.  t.  24,  f.  163a-c. — Ischnochiton  longicymba  CPR.,  MS., 
and  of  HADDON,  Challenger  Rep.  Polyplac.  p.  17  (not  Ch. 
Imtgifymba  Quoy). 

Having  examined  extensive  suites  of  specimens  of  the  longi- 
cymba type  of  Ischnochitons  from  New  Zealand  and  Australia,  I 
find  myself  compelled  to  separate  specifically  those  from  the  latter 
locality,  although  in  general  appearance,  color  and  sculpture  they 
certainly  resemble  the  true  longicymba.  The  differences  indicated 
above,  and  shown  in  the  figures,  seem  to  be  remarkably  constant, 
and  readily  recognized  if  one  takes  the  trouble  to  look  for  them. 
It  must  be  admitted,  however,  that  to  thoroughly  examine  a  small 
( 'hiton  involves  some  little  trouble;  and  therefore  we  must  feel  no 
surprise  if  the  superficial  collector  and  the  often  no  less  superficial 
author,  continue  to  confound  species  which  are  really  distinct.  It 


ft     IIMM     III    l< 

must  be  said,  however,  that  the  confusion  of  these   two  ip 
probably   been   due  to  the  hick  of  specimens  from  the  two  localities 
for   comparison  ;    else   the    dilli-rcnccs    would    hardly   have   escaped 
writers  so  careful  and  observant  as  Carpenter  and  Iladdon. 

I.  CRISPUS  Reeve.     PI.  24,  figs.  98,  99  (enlarged). 

Shell  rather  elongately  ovate;  terminal  valve-  and  lateral  areas 
of  the  rest  finely  decussately  granulately  crisped,  central  areas 
smooth,  or  under  the  lens  very  minutely  reticulated.  Olive-green, 
thickly  painted  with  dots  of  a  darker  color.  Ligament  minutely 
grauulously  coriaceous,  obscurely  tessellated.  (Reeve.) 

Australia. 

C.  crispus  EVE.,  Conch.  Icon.  t.  19,  f.  120,  May,  1847. 

Allied  to  C.  longicymba,  but  distinguished  from  that  by  the  min- 
ute decussated  character  of  the  sculpture  of  the  lateral  areas. 
(Eve.) 

Carpenter  seems  to  think  this  simply  a  pale  variety  of  C.  longi- 
cymba,  saying  that  he  cannot  see  the  decussation  spoken  of  by 
Reeve,  unless  it  is  from  the  concentric  ribs  of  growth  seen  in  some 
of  the  specimens. 

In  view  of  the  inadequate  description  and  figure,  the  species  had 
better  be  dropped. 

I.  PALLIDUS  Reeve.     PI.  23,  fig.  91  (enlarged}. 

Shell  oblong-ovate,  valves  smooth  throughout;  dead  white;  lig- 
ament horny,  arenaceous,  brown.  (Reeve.} 

Australia. 

C.  pallidus  REEVE,  Conch.  Icon.  t.  16,  f.  92,  March,  1847.— Isch. 
pallidus  CPR.,  MS. 

Carpenter's  notes  on  the  specimens  in  the  British  Museum  are  as 
follows,  but  I  am  not  sure  that  these  are  Reeve's  species :  Shell 
almost  exactly  like  L  longicymba,  gothic-arched ;  whitish,  ashen,  or 
variously  tinged  or  streaked  with  roseate,  blue  and  olivaceous ; 
jugal  area  scarcely  defined,  jugum  obtuse ;  central  areas  wrinkle- 
striated,  the  wrinkles  irregularly  tending  forward  toward  the  jugum, 
sometimes  v-shaped;  lateral  areas  well-defined,  having  12-30  gran- 
ulate-wrinkled stride,  sometimes  the  wrinkles,  sometimes  the  gran- 
ules predominating,  sometimes  having  concentric  growth  wrinkles. 
Mucro  median,  rather  elevated,  the  slope  behind  it  little  concave. 
Interior :  front  valve  with  11,  central  1,  posterior  valve  13  slits  ;  teeth 


'.«)  ISCHNOCHITON. 

acute  ;  sinus  very  broad,  flat  ;  eaves  large,  scarcely  spongy.  Girdle 
thin,  irregularly  imbricated  with  very  small,  very  close,  solid,  sub- 
elevated,  conspicuously  sulcated  scales.  Australia.  Five  speci- 
mens, P>.  M..  the  tablet  including  two  specimens  of  longicymba  and 
one  of  Heterozona  cariosa  f. 

In  the  first  specimen  the  radiating  sculpture  is  almost  lost  in  the 
i:ranulc<  in  the  side  areas.  The  painting  is  sometimes  with  delicate 
broken  lines  of  brown  longitudinally.  Sometimes  one  jugular 
patch  more  or  less  broken  into  streaks,  side  areas  rarely  if  ever 
painted,  but  often  tinged  with  bluish  green.  The  specimen  opened 
B.  M.  has  2  central  teeth  on  posterior  valve  changed  into  an  irreg- 
ular series  of  pectinations  evidently  consequent  on  an  injury. 


I.  INQUINATUS  Reeve.     PL  18,  figs.  49,  50  (enlarged). 

Shell  oblong-ovate  ;  terminal  valves  and  lateral  areas  concen- 
trically, somewhat  obscurely  ribbed,  finely  radiately  grooved;  cen- 
tral areas  longitudinally  finely  ridged.  Ligament  horny,  arena- 
ceous. Whitish,  stained  with  a  light  brown  spot  along  the  summit 
of  each  valve.  (Rve.} 

Tasmania. 

C.  inquinatus  RVE.,  Conch.  Icon.  t.  23,  f.  154,  May,  1847.  —  Isch- 
nochiton  inquinatus  CPU.,  MS. 

The  shell  is  sometimes  partially  stained  throughout  with  the 
faint  brown  color  which  appears  on  the  umbonal  summit.  (Rve.) 

Compare  /.  divergens  Rve. 

I.  DIVERGENS  Reeve.     PI.  22,  figs.  74-77. 

Shell  oblong,  moderately  elevated,  varying  from  obsoletely  to 
distinctly  angled  at  the  dorsal  line.  Lateral  areas  raised  and 
rugose.  Color  very  variable,  but  usually  a  light  green  tint,  spotted 
with  dark  olive-brown,  or  cream-white,  variegated  writh  olive,  olive- 
brown  or  dull  scarlet. 

The  raised  lateral  areas  are  sculptured  with  a  varying  number  of  bi- 
furcating or  irregular  riblets,  the  surface  between  them  being  granular. 
Central  areas  sculptured  in  the  middle  with  very  fine  subgranose  strice 
diverging  forward  /\-likefrom  the  dorsal  ridge  ;  pleura  or  sides  of  the 
<•<  ntral  areas  having  stronger  longitudinal  rugce  at  the  sides  and  on 
the  diagonal  slope  ;  a  region  of  fine  zigzag  striation  sometimes  inter- 
vcninir  between  the  side  corrugation  and  the  A'like  >t  nation  of  the 
jugal  tract.  End  valves  sculptured  like  the  lateral  areas.  Umbo 


i~<  n\'M  111 1.  :u 

of  iln-  posterior  valve  rather  acute,  in  front  of  tin-  middle  : 
slope  concave. 

Interior  whitish  or  bluish,  marked  at    tin-  >inns   \\itli    1>1 
and  posteriorly  with  rose  ;  the  tail  valve  haviirj  a  conspkmooi  Nark 
crescent  in  the  middle.      Anterior    valve    having    l<>    ll;.   central    1, 
posterior  valve  10-13  slits;  teeth  sharp;   cave-  narrow,  -olid. 

Girdle  indistinctly  tessellated  with  purplish  on  a  paler  Around, 
covered  with  forge,  convex,  closely  and  deeply  ftriaUd  9oM  -• 
(fig.  74).     Length  28,  breadth  14  mill. 

Port  Jackson,  AurtraKa. 

Chiton  diver  gens  REEVE,  Conch.  Icon.  t.  8,  f.  44. —  Ch.  proteus 
REEVE,  /.  c.,  t.  18,  f.  111. — Lepidopleitrus proteus  ANCAS,  I'.  /  8, 
1867,  p.  222. — Itchnochiton  divergens  and  Inch,  proteus  CPR.,  JA\. 
Isch.  intricatus  and  Isch.  intricandus  CPR.,  MS.,  olim.  * 

This  species  differs  from  I.  longicymba,  haddoni  and  //•/// /ra*t/.>-  in 
the  very  much  larger  convex  scales  of  its  girdle.  It  has  the  lateral 
areas  much  as  in  I.  fruticosus,  but  the  median  portion  of  the  cen- 
tral area  is  more  distinctly  patterned,  and  the  jugum  is  subcar- 
inated.  It  varies  greatly  in  coloring,  and  usually  has  some  roae- 
pink  inside. 

/.  divergens  has  been  erroneously  united  to  fruticosus  by  Angas 
and  by  Haddon.  It  should  be  understood  that  all  of  the  detail 
drawings  of  the  girdles  are  drawn  to  exactly  the  same  scale;  if  this 
be  considered,  the  student  need  not  hesitate  in  identifying  the  pres- 
ent species. 

I.  FRUTICOSUS  Gould.     PI.  23,  figs.  78,  79,  80. 

Shell  oblong,  moderately  highly  arched,  the  back  rounded,  not 
carinated.  Surface  lusterless  and  showing  distinct,  irregularly 
radiately  roughened  lateral  areas.  Color  usually  grayish  or  light 
green,  becoming  olive-green  or  brown  toward  the  sides,  and  more 
or  less  spotted  with  blackish. 

The  lateral  areas  are  raised  and  irregularly  sculptured 
with  a  varying  number  (3-6)  of  bifurcating  subno<lo>r 
radiating  riblets,  the  posterior  one  of  which  is  transformed 
into  a  series  of  nodes;  the  other  riblets  often  much  interrupted 
(fig.  80),  but  sometimes  nearly  continuous;  intervals  between 
the  riblets  are  finely  granulated.  The  central  areas  are  either 
minutely  and  evenly  shagreened  in  the  middle,  much  as  in  /.  lonyi- 
cymba,  except  that  the  granules  are  more  distinctly  arranged  into 


92  ISCHNOCHITON. 

oblique  zigzag  rows  ;  but  toward  the  sides  of  the  central  areas, 
along  the  diagonal  slope,  a  coarse  sculpture  of  longitudinal  wrinkles 
is  developed.  End  valves  sculptured  like  the  lateral  areas;  umbo 
of  posterior  valve  rather  obtuse,  the  posterior  slope  concave. 

Interior  white  and  blue  or  blue-green;  posterior  valve  having  a 
black  crescent.  Anterior  valve  having  10,  central  valves  1,  poste- 
rior valve  9  slits.  Teeth  sharp,  thin,  smooth  outside,  but  slightly 
roughened  inside ;  posterior  tooth  of  the  side  plates  terminating 
abruptly  near  the  posterior  edge  of  the  valve.  Eaves  narrow,  solid. 

Girdle  indistinctly  marbled  with  ashy-purple  on  a  paler  ground  ; 
very  closely  covered  with  microscopic,  deeply  imbricating  striated 
scales  (fig.  79).  Length  33,  breadth  15  mill. 

New  South  Wales. 

Chiton  ftuticosus  GOULD,  Proc.  Bost.  Soc.  Nat.  Hist,  ii,  p.  142 
(July,  1846)  ;  U.  S.  Expl.  Exped.  p.  319,  f.  428  ;  Otia,  p.  4,  242. 
— Ischnochiton  fruticosus  CARPENTER,  MS.  and  of  HADDON  ?  Chal- 
lenger Polyplac.  p.  17. — Isch.  sowerbyi  n.  s.  ?,  CPR.,  MS. 

This  species  has  the  lateral  areas  more  roughly  and  irregularly 
sculptured  than  /.  longicymba  or  /.  haddoni,  and  the  girdle  is  some- 
what more  compactly,  flatly  scaled  than  either.  The  external 
sculpture  of  the  valves  is  extremely  similar  to  /.  divergens  Rve.; 
but  the  latter  differs  totally  in  its  very  coarsely  pebble-scaled  girdle. 

I.  SCULPTUS  Sowerby.     PL  23,  figs.  89,  90. 

Shell  subelongate,  depressed,  subattenuated  in  front,  back 
rounded.  Central  areas  smooth,  striated  at  the  sides  ;  lateral  areas 
ornamented  with  radiating  exfoliating  ribs ;  margin  smooth. 
Length  20,  breadth  10  mill.  (Sowb.) 

Habitat  unknown. 

C.  sculptus  SOWERBY,  Mag.  of  Nat.  Hist,  iv,  p.  292,  June,  1840  ; 
<  "nch.  Illustr.  No.  44,  f.  66.— REEVE,  Conch.  Icon.  no.  177,  t.  26, 
f.  121. 

A  beautiful  little  shell,  remarkable  for  the  exfoliated  sculpture  of 
the  lateral  areas,  on  each  side  of  which  there  are  three  radiating 
series  of  strongly  relieved  laminae.  The  central  areas  are  nearly 
smooth  except  at  the  sides,  where  they  are  slightly  striated.  The 

niaririn  i-  nearly  sm<>oth,  li.trlit  brown  invirularly  striped  with  gray  ; 
and  the  general  color  is  creamy-white.  (Soivb.) 


EBOHHOCB]  i' 

I.  coNTSAcrua  Reeve,     I'l.  23,  figs.  81,  g 

Shell       oblong,       peculiarly       runt  ractrd      ;it       tin-       rxhvn 
especially     tin*    anterior;     terminal     valves    and     lateral 
tin-     rest     concentrically     granulated,    granule^     solitary,     central 
areas    very    minutely    and    closely    ridded,    ridges   curved    and    OOD- 
spicuous   towards  the  >idcs,  finer  towards  the  middle  and  drni»at«-d 
with   ohli(|iie  stria-:    light    hay,   flamed    in    the   middle  with  hrown  ; 
ligament  granosely  coriaceous,  dark  hrown.     (live.) 

TiH*innniii   •  Mil-.  (  'inn 

( '/ilton  contractus  KEEVE,  Conch.  Icon.  1. 1^,  fi;r.  7*,  March,  1847. 
—  (1hiton.  (IcciiMttH*  RI:I:\  I-;,  Conch.  Icon.  t.  18,  f.   107,  April,  1>  17. 
—  Chiton    rattu*    IvVK.,    t.    22,    f.    14-"),    May,    1847.—  /.>•'•/, n^-hitn,, 
castus  CPR.,  MS.,  and  7.  interyranosus  CPR.,  MS. — Lr/, ;<!<,/, /, 
.^Hclosus  H.  AD.  &  ANGAS,  P.  Z.S.  1864,  p.  \»'2 ;  /.  r.,  1S0T),  p.  187. 

This  species  has  heen  several  times  described,  but  the  range  of 
variation  seems  to  be  less  than  in  some  other  allied  forms,  although 
the  coloring  varies  considerable.  The  acute  dorsal  ridge,  divergent  or 
zigzag  sculpture  of  the  dorsal  areas,  the  granulation  of  the  lateral 
areas  and  serration  of  the  sutures  are  characteristic.  The  descrip- 
tions of  the  several  forms  included  under  contractus  follow  below. 

Carpenter's  notes  are  as  follows:  shell  oval,  subelevated,  ashv, 
irregularly  streaked  with  brown-olive.  Otherwise  like  /.  c</ 
but  the  central  areas  are  everywhere  zigzagly  wrinkled,  the  lines 
which  in  castus  are  conspicuously  at  right  angles  to  the  diagonal 
line  are  not  seen  in  contractus.  Lateral  areas  and  end  valves  hav- 
ing close  radiating  wrinkles,  more  or  less  broken  into  granules  con- 
centrically, sometimes  scarcely  at  all,  sometimes  entirely  so.  Inte- 
rior: anterior  valve  having  14,  central  valve  1,  posterior  valve  13 
slits;  teeth  acute;  eaves  conspicuous,  hardly  spongy;  sinus  wide, 
flat,  smooth  ;  it  appears  broader  and  the  sutural  lamina?  not  so  high 
as  in  castus.  Girdle  pale  black-brown  :  scales  as  in  7.  nidus. 
Length  37,  width  17^'  mill.;  divergence  110°. 

There  are  3  specimens  in  the  Cuming  collection,  from  Tasmania, 
and  two  on  the  same  tablet  which  are  really  an  intermediate  variety 
of  I.  castus.  I  cannot  see  the  contracted  sh a j H'  figured  hy  Keeve, 
in  either  of  the  specimens,  which  are  shaped  just  like  7.  /<»i</ici/ml>a. 
The  streaked  coloring  is  quite  exaggerated  :  it  is  very  irregular,  not 
in  even  lines  as  in  Reeve's  figure.  The  divergence  is  the  .-ameasin 
7.  castus.  Side  by  side  they  exactly  correspond.  The  difference 


i!\«-    111  ! 

in  tin-  >inu>  is  perhaps  accidental,  from  their  being  older  specn 

"•0 

'.<aahw  Reeve.     (PI.  23,  li.irs.  83,  84.)     Shell  oblong-ovate, 

a  little  attenuated  posteriorly.     Terminal    valves   and    lateral   areas 
ned,   the  grains   rather  obtuse,  numerous,  irregular,  intei  - 

»ated  with  very  close  slightly    wrinkled 
Pale  \vllowi>h-<:recn,  flamed  along  tlie  suiuinit  with    brown. 

Rpe.) 

Australia    Mus.  Cuming,  1  specimen). 

<  .  r,,.<tn8  Reeve.  (PI.  23,  figs.  87,  88.)  Shell  oval,  subelongate, 
rather  elevated,  orange  tinted  with  red  :  juirum  acute:  mucro  rather 
raised,  median,  the  slope  behind  it  concave.  Central  areas  cloM-ly 
wrinkled,  the  wrinkles  at  the  ju-rum  divenriiiLr  laterally,  sometimes 
interrupting  one  another  and  forming  zigzags.  Lateral  areas  and 
end  valves  with  concentric  nodular  wrinkles,  sometimes  the  wrinkles, 
-ometimes  the  nodules  predominating;  nodose  at  the  sutures. 

Interior  orange-flesh  tinged ;  front  valve  with  9,  central  1,  poste- 
rior 1')  slits ;  teeth  acute,  scarcely  pectinated  ;  sinus  wide,  flat,  deep, 
>liirhtly  and  very  minutely  denticulated  by  the  external  sculpture; 
laigc,  hardly  spongy. 

Girdle  olivaceous,  slightly   tessellated,   imbricated    with    large, 
wide  and  solid,  deeply  striated  scales.     Length  21,  breadth  12  mill. : 
irence  103°.     (Cpr.,from  type  specimen.) 

A  n^rnlin. 

The  ireneral  characters  of  this  species  are  the  same  as  in  Irstili* 
and  rat'iosus,  but  it  differs  sufficiently  in  sculpture.  Both  of  the 
two  specimens  in  the  Brit.  Mus.  are  curved  up  so  that  thev  cannot 
be  measured  accurately. 

Another  form  which  Carpenter  described  in  J/N.  as  "  1.  cimtn*  n. 
>p.,"  but  which  he  afterward  decided  to  be  synonymous  with  wnthut 
.  i>  white  with  a  black  «rirdle.  The  shell  is  much  elevated  with 
acute  juirum  ;  the  central  areas  have  delicate  but  much  raised  lira, 
about  •')<>  on  each  >ide,  and  subparallel  except  toward  the  ridge 
where  they  bend  outward,  and  upon  the  juirum  they  are  elegant! v 
undulating.  The  lateral  areas  and  end  valves  have  rather  large, 
separ:  rly  radiating,  serrating  the  sutures.  The 

anteri<.r    valve    has    13,   central   1,   posterior   valve   11    slit>.     The 
irirdle  U  clothed  with  narrow,  stout,  deeply  grooved  scales.     Len^tli 
::n.  breadth  \\\   mill.;    divergence   110°.      It   is   from    Su>«,t    /,' 
MII-.  ( 'umini:.  No.  100). 


l-«    UN'"    III 

.</"  7'"'x"-v-      Hirll    I' 
nient.d  longitudinally  with  n  d  -bni\\M,  the  margin  with  a 
Centric    green    BOne.       Kml    valves    ami    lateral    area*    .  ally 

ribbed,  the  ribs  pii-tulo-e,  interstice*  minutely  Lrranulated.      Lateral 
area-  stiiiirwhat  elevated.      Median  valve-  eaiinated.      I)or.-al  .. 
divaricately    wrinklr-st  riatr<!.      (iinllc    pah-    l»ru\\n,    eOTered     with 

ly  imbricating  scales,     I.rn-th  :;.'»,  Ix-ca.lth  \in  mill.    (Ad.& 


I 

'l'hi>  i>  an  excellent  description  of  the  exterior  of  this  species. 
[.  COLUBBIFEB   Kccvc.      1M.  L;  1  ,  tiirs.  51,  52. 

Shell  ohlonu'-ovate,  somewhat  elevated  in  the  middle.     Terminal 
valves  and   lateral  areas  peculiarly  flat-drained,  cent  ral  ana- 
finely  reticulated  with  circular  and  obliquestlifiB,      Whiti.-li  l)l«>i. 
with  Itlaek  ;  li-ament  scaly.     (Reeve.~) 

Habit"!  »////•/' 

C.  colu  In-  it')-  RKI:\  i:,  Conch.  Icon.  t.  28,  f.  188,  Jan.,  184N.--/.W,- 
nockiton  colubrtfer  CPR.,  MS. 

Carpenter  writes:  Three  specimens,  Mus.  Cuming.  Very  like  a 
yoiini:  variety  of  the  castu*  group.  Shell  arched,  not  keeled,  ele- 
vated ;  ashy,  spotted  with  dark  here  and  there,  tinged  with  orange 
about  the  umbos,  which  are  not  beaked.  Central  areas,  and  the 
undifierentiated  jugal  areas,  covered  with  a  minute  granulation, 
runniiiLr  perpendicular  to  the  diagonal  line  and  then  brandling  off 
into  wrinkles.  Lateral  areas  and  end  valves  having  granulations 
running  into  coarse  concentric  wrinkles.  Posterior  valve  bavin- 
10,  central  valves  1,  anterior  valve  9  slits;  teeth  extremely  sharp 
and  tine;  sinus  broad,  deep,  smooth,  deeply  channelled  at  the  bi 
eaves  long,  solid.  Girdle  having  typical  Ischnoid  scales,  rather 
large,  flat,  broad,  thin,  regularly  imbricated,  very  finely  striated. 

Length  16,  breadth  7  mill.;  divergence  about  83°. 

I.  I-ALLIDULUS  Reeve.     PI.  23,  figs.  96,  97. 

Shell  elongated;  terminal  valves  and  lateral  ar  utrieully 

undulately     wrinkled;     central     areas     minutely     rough;     whitish 
throughout;  ligament  horny,  arenaceous,  whitish.        /,' 

Il'iltit'it  n>ik> 

C.  paWidti/iw  EEEVB,  Conch.  IOOD.  t.  L'O,  f.  131,  May.   ; 

IscJino'-hifon  /Ktllidnliix  Crii.,  .1/N. 


96  ilN"<   I  II  TON. 

Carpi-mer   gives  the  following    aotee:      Anterior   valve    with    !'. 

:al  valv.s  1  ,  posterior  valve  9  slits;    teeth   typically   Ischnoid  ; 

.-inns  deep,  broad,  channelled,  flat  ;  eaves  moderate.     Jugum  obtuse, 

elevated;  central  areas  very  conspicuously  granulated  in  quincunx. 

ing  somewhat  into  the  Y-culpttiiv  :   lateral  areas  c»»nspicinMi>ly 

raised,  concentrically  wrinkled,  "  thuinhy."     Mucro  central.     <iir- 

dle  with    pretty    large,    broad,    thin,    distinctly    striated    regularly 

imbricated  scales.     Length  22,  breadth  10}  mill,  ;  divergence  106°. 

The  peculiarity  of  the  shell  is  the  elongation.  It  is  probably 
Australian  and  belongs  to  the  /.  contractus  group. 

I.  1-1  ii  \n-  Reeve.     PI.  24,  figs.  11,  12  (enlarged). 

Shell  elongately  ovate;  terminal  valves  and    lateral   areas   radi- 
ately  ridged;  ridges  wrinkled,  here  and  there  grained  and  bifur- 
1  :    central   areas   very   minutely   reticulated.     Burnt   brown. 
Ligament  granosely  coriaceous.     (Reeve.) 


('.  Httulatus  REEVE,  Conch.  Icon.  t.  17,  f.  102,  March,  1847.— 
!.«•},,  lor/titon  ustulatus  CPR.,  MS.  —  Lepidopleurus  untHftitn*  A  N<  ;  AS,  P. 
/.  -  1*<>7,  p.  222. 

Carpenter  briefly  notes  that  the  scales  of  the  type  specimens  an 
rather  gravelly  and  irregular,  very  small,  but  apparently  a  little 
>triated.  The  drawings  of  scales  and  valves  given  on  my  plate 
were  prepared  for  Carpenter,  presumably  from  specimens  in  th»- 
collection  of  Mi-.  Win.  A.  Ilaines,  of  New  York  City. 

I.  <  -A  KI  NT  i.  ATUS  Reeve.     PI.  23,  figs.  94,  95. 

The  finely  keeled  Chiton.  Shell  oblong-ovate,  terminal  valves 
and  lateral  areas  of  the  rest  concentrically  and  radiately  somewhat 
obscurely  ridged  and  sculptured  with  obtuse  granules  arranged  in 
wrinkles,  central  areas  also  granulated,  smooth  in  the  middle, 
peculiarly  keeled  at  the  summit;  ruddy  rose;  ligament  finely 
squamately  coriaceous.  (Rve.) 

T«.<i 

C/i.  r.i,'hu</tifn*  RKKVK,  Conch.  Icon,  t,  23,  f.  158,  May,  1847.— 
Tschnochiton  cnriiinlntun  OK.,  MS. 

Carpenter's  notes  on  the  single  type  specimen  in  the  IJritish 
MiiHMim  are  as  follows:  Along,  narrow,  rather  ;,o///V-///vm/  >hell, 
the  shape  of  longicymba.  Girdle  with  very  small,  distincilv  but 
ti  n.  ly  striated  scales.  Mucro  at  the  anterior  fourth.  .Ingmn  rather 


ilN'M    III   I 

shaip,  curiously  marked  by  a  long,  narrow   white  line  \\i,i,  h   , 

he     accidental.        (  'flit  I  II I     areas    li:i\  1! 

granulation!  :   falling  invjuhirly  into  coi  rin:at  inn 

-rain-.       Lateral    aie;i-     moderate! v     rai-  -I.     \siili 

wrinkling    pa.-.-ini:   OVer    about    four    very    lilunt  ob-ohte  rib-  :  end 

Valves  obsoletely    radiated.      Inieiior:     posterior    v:il\.  11, 

mitral    \al\vs    1,    anterior    valve  1  0  -lit- ;   teeth  sharp,  i.in  ; 

sinus    broad    hut   shallow,    very    -traiirln,    -mo^th,    not    channelled  ; 

eavee  moderate,  rather  close  to  the  teeth.     Len-ih  LI},  breadl 

mill.  :   divergence  Id.".   . 

I.  CUIMIHVM  -  I'-.  A.  Smith.      PI.  L'l.  li-.  U  lenlai 

Shell  oval,  llattish,  of   a  dirty  dark  irravish  color,    havini:   a    • 
spictious   black    hroadish    line    from    end  to  end  do\vn  the  middle  of 
the  hack,    with   a   pale  one  on  each  side  of  it,  and  with  the  mantle 
patched  alternately  li^lit  and  dark,  irregularly  granulated  through- 
out.    Valvi-s  arched,  not  carinate  at  the  vertex,  with  verv  indi- 
lateral  areas,  exhihiting  strong  concentric  lines  of  growth,  e-pecially 
conspicuous  at  the   sides    and   anterior  maririiis.      Front  plat*-  well 
curved   anteriorly,   the  posterior  margin   beini:   hroadly   sinnat'  d. 
Second   plate  longer  than  the  other  intermediate  valve-,  sli-htly 
incurved  on  each  side,  the  central  outcurved  point  in    front,   rather 
peaked   in  the  middle  of  the  hinder  edge.     The  third,  fourth,  fifth, 
sixth   and  seventh  valves  are  very  short  in  comparison  with  their 
width  in  proportion  as  1  is  to  3.     The  jngal  sinus  is  large  and  arcu- 
ate.     Last  valve  of  a  narrow  acutely  elliptic  form,  with   the   n 
prohably  near  the  center.      Interior  of  the  plates  greenish-hlue, 
stained  dark  hrown   in  the  middle.      Lt'inina-  of   in>ertioii    in    tin- 
front    plate   with    about  ten    notches  at  unequal  distance-,  leaving 
diflerent  sized  teeth  between  them,  which  an-  ,-tiiated  on  both  .-ides, 
but  more  strongly  externally,  their  edges  being    sharp,    but    not 
smooth.     The  central    plates    have  a  single   minute   notch  OH  each 
side,  the  insertion  lamina  being  Comparatively  Miiooth  on  the   upper 
surface  and  marked  \\ith  a  small  brown  spot   on    each    .-id 
the  edge  of  the  valve.     Tail  plate  much  thickened  \\itliin  aloii. 
posterior  edge,  which  is  roughened  by  fine  crOSB   stria-,    th- 
no  prominent  teeth,  and  of  course  no  notches.      .Mantle  mar-in  cov- 
ered   with    small    snbimbricating  oval    grannies.      Length    without 
margin  l(i  mill.;   width  of  fourth  plate  '.». 


98 

The  granules  of  the  surface  have  an  irregular  concentric  <1 
tiiin,  fnllo\\iniLp  t<>  .-Mine  extent  the  lints  of  growth.      (Smith.) 

r<>rt  Curtis 

Chit»it  i  l.<rhnnrl,itiin  -  curtwctnut  SMITH.  Kep.  on  /ool.   Coll.    II. 
M.S.  'Alert;  P.  78,  t.  6,  f.  I).  U 

This  i-  certainly  not  a  typical  /^-hmn'hifou.     It  i-  difficult,  with- 
out an  examination  of  a  Specimen,  to  refer  it  to  its  proper  gcnu-. 

I.  BXiouuB  Sowerby.     IM.  i>3,  figs.  85,  86. 

Shell  oblong,  small,  rufescent,  narrow.      Intermediate  valves  hav- 
ing a  very  wide  trigonal  dorsal  cariua,  the  margins  grooved  :   lateral 
*s  distinctly  defined.    Length  4*1,  breadth  !•:;  mill.    (Soivb.) 
This  is  the  smalleM    species   Mr.  So\\erl>y    has  seen;    the  dorsal 
ke.-|  ot'  the  intermediate  valves  is  very  broad,  and  distinguished   l>y 
OV6  <>n  each  side.      (Sowb.) 

•d  Hood's  ItlamI,  7V//mW».  <>n  Pearl  ()y- 

riu'fnn  exigvuiSoWB.,  P.  Z.S.  18,32.  p.  104;  Conchol.  Illustr.  f. 
36.  —  REEVE,  Conch.  Icon.  t.  28,  f.  186.  —  Ischnochiton  exigwu  Ci-i:.. 


Carpenter  writes:  Interior:  end  valves  having  14-16  slits,  cen- 
tral valves  1  slit:  .-inus  wide,  curved;  girdle  irregularly  clothed 
with  large,  slightly  striatulate  scales.  Habitat,  Centm/  I'-n-ifi*- 
(Pease).  Mr.  Pease's  solitary  specimen  seems  conspecific  with  Mr. 
Ciiminir's  hitherto  unique  specimen  from  Lord  Hood's  Island.  It 
is  in  better  condition  than  the  type,  but  extremely  minute  and  evi- 
dently very  young. 

2.   Group  of  I.  textili*. 

itral  a  i-eas  granulated,  becoming  striolate  at  the  sides:  lateral 
areas  radially  wrinkled.     South  African  species. 

\  1  1  us  Gray.      Unfiyuretl. 

Shell  itbhnnj,  e/oHiftite,  white,  pellucid  when  youn<r,  f/reen  ^clth  a 

»//////•  i-rnfrnt  /'"ml  ;  convex  above:  end  valves  and  lateral  area-  of 

the   middle   valves   finely    radiately     striated     and    concentrically 

wrinkled;   central  area  closely  an<!  minutely  jiuncfufcd,  find  /»'liin<I 

longitudinally  *t/-i<it«l  ;   maririn  [girdle]  white,  minutely  scaly. 

jth  one  inch  and  a  half.     (Gray.) 

('"peof  Good  I/nj.c  (Capt.  Carmichael,  Mus.  l>rit.). 

Cli>  \U  (-i:  \v.  Sjiieileiria  /oolo^ica,  pt.  1,  p.  ">,  pi.  (I,  f.  20 

Muly  1,  1828).—  KRAUSS,  Die  Sndafiic.  Moll.,  p.  38.—  (?)  I'h.solca 


UN...    Ill   I'  !•!» 

..  (  'ouch.  llliMr.  !'.  HI      n»i  d.-crihed,  RE 
•////.>•). —  Not  ( '/i.  //•./•////  '.'I . 

The   ahove  dc-ciiplio||    is    from    ' 

taut  panagee  hem-  italicized  h\-  on 

worthless.       Keevc's    liiruiv   and    description    do    n..t    pi -rtain  to  t  hi- 

species,  hut  to  I.  (Radsiella)  xebra  Kran-        ,       true   /.  •• 

iii  all  respects  a  typical  Ttehnochiton,     I  refer  the  no  d  C. 

mtlt-,1  of  Suwerhy  to  t,.rtili.«  becaOM  il   i-  -aid  to    IK-    that    tpeckl    l>y 
S,. \vt-rhy    hiinsclt';    l»ut    the  figure  i>  VTV  poor,      The  detaUl  h 

u'ivcn  will  enable studenta  to  identify  (H  .ith  eomj 

alive  ease  and  certainty,  without  a  figure;  for  it  wemi  to  he  closely 
allied  to  the  /.  oni*<'n.t  only  ainoiiLr  South  African  < 'Into 
details  of  sculpture  of  the  central  areas  and  the  coloring  «-em  to  he 
especially  characteristic.  Krauss  de.-crihe-  specimen.-  collected  hv 
him,  and  which  he  at  one  time  considered  a  new  species  which  he 
intended  naming  C.  li«l>r!</i.  His  description  is  as  toll 

Shell    ovate-elonpite,  semipellucid,   snhcarinated  :     white   in    the 
middle,  the  sides   ashen-green,  often  spotted  with  hrown  ;  int 
white.     Front  valve  lunate,  tail  valve  rather  depreased,  >uhmucro- 
nate  in   the  middle;    intermediate  valves   having  the  central  areas 
finely  punctate  on  the  ridge,  longitudinally  striolate  at  the  sides; 
lateral  areas  and  end  valves  radiately   rugulose-striated.     (iiidle 
a-hi'ii,  suhniaculated,  scaly,  the  scales  small  and   ohlonir,   > . 
finely  multicn rln ,<ifed.     Length  22,  breadth  11  mill.     Tahle  Uay. 

The  anterior  valve  and  the  posterior  part  of  the  posterior  valve 
are  radially  wrinkle-striated  and  have  1 '_'  >lits  in  the  insertion 
plates,  which  are  smooth  and  shorter  than  the  eaves.  The  median 
valves  are  rather  narrow  (8'6  x  3  mill.)  and  have  distinct  lateral 
areas  with  5  to  6  strong  wrinkle-like  and  interrupted  stria-.  The  cen- 
tral areas  are  seen  under  a  lens  to  be  covered  with  fine  raised  points, 
which  toward  the  margins  become  more  and  more  di-tinct,  and 
near  the  lateral  margins  as  well  as  in  front  of  the  hit  oral  areas  they 
unite  into  distinct  longitudinal  rows.  The  sutural  plates  are 
rounded;  insertion  plates  short ,  smooth,  and  having  a  single  slit. 
The  girdle  is  covered  with  extremely  small,  thin  longitudinal  » 
not  discernahle  to  the  naked  eye,  and  prettily  marki  d  with  8-9 
stria\  The  color  is  whitish  in  the  middle  of  the  shell.  Lrrayish- 
green  on  the  sides,  and  dotted  and  llecked  throughout  with  brown. 

Krauss  also  describes  the  following  : 


100  1-'   IIN«»<  III  1 


Var.  jiuni'tn/'ttu.    Shell  carinated.  ashen-wbitisb,  unicolored  or 

>  d  and  dotted  with  brown  ;  very  finely  punctate.  Lateral 
areas  and  end  valves  radially  striated.  Length  *2'2,  breadth  10 
mill.  Tin-  valves  are  keeled  and  covered  with  regularly  arranged 

..:«-d  points  only  to  he  seen  under  a  lens. 

A-  an  illustration  of  tins  variety  Kranss  refers  to  Sowerby's 
Gout-hoi.  Illn.-tr.  fig.  ">"),  but  in  my  opinion  this  i-  not  correct. 

I.  OKI8CU8  Krauss.      PI.  20,  figs.  12,  3,  14,  1  "). 

Shell  small,  ovate-oblong,  tbin,  semipellncid,  subcarinatod  ;  white, 
rarely  with  a  reddi-h  dor.-al  baml,  or  yellowish  with  green  dots. 

Intermediate  valves  having  the  central  areas  very  finely  punctu- 
late  in  tbe  middle  and  longitudinally  striolate  at  the  sides;  lateral 
areas  and  end  valves  finely  undulately  striolate.  (iirdle  yellowish, 
mandated  with  Lrreen,  scaly,  the  scales  very  minute,  oblong,  smooth. 
(Kraws.}  Length  10,  width  5'6  mill. 

Natal,  on  the  shore. 

Chiton  oni'tcus  KR.,  Die  Siidafric.  Moll.  p.  39,  t.  3,  f.  4.—Tschno- 
chiton  oniscus  CPR.,  MS. 

This  species,  whilst  it  has  a  superficial  resemblance  to  /.  text  His 
<iray,  is  readily  distinguished  under  the  lens  by  the  smaller  and 
smooth  scales  and  by  the  smaller  number  of  slits.  The  valves  as 
well  as  the  girdle  appear  smooth  to  the  naked  eye,  but  the  lateral 
areas  are  visible.  Under  the  lens  the  central  areas  are  very  tinelv 
punctate  on  the  dorsum,  and  on  the  pleura  they  are  longitudinally 
striated  ;  these  stria3  continue  upon  the  lateral  areas  becoming  wavy 
there.  Tin-  end  valves  have  feeble  wavy  stria?  toward  the 
margins,  and  have  10  slits  in  their  insertion  plates.  The  intenne- 
diat«-  valve-  are  strongly  convex,  ~>  mill,  wide,  4  lon^r,  rounded  at 
both  .-ides,  and  having  a  single  slit  in  each  insertion  plate.  One 
specimen  is  white  with  greenish-brown  girdle  ;  another  is  whitish 
with  a  rod-brown  hand  along  the  back  ;  a  third  specimen  is  dirty 
yellow  with  green  dots,  the  girdle  also  green  dotted.  (Kru< 

(  arpenter  gives  this  note  on  specimens  received  by  him  from 
Stimp-nii  :  Terminal  valves  having  10-  PJ,  central  1  slit:  teeth 
acute  ;  eaves  short,  spongy  ;  sinus  broad,  Hat.  In  one  of  the  .-pen- 
men- examined  the  hind  valve  has  the  central  teeth  very  small  and 
close,  while  the  side  teeth  are  long  and  distant. 


In] 
I.  YI:I:I;I  I:M   }•'..  A.  Smith.      I'l.  1  1. 

Shell  small,    depn».-d.     >li<jhlly     carinated     in     tlic    middle; 
-ray    maculated    with    dull    L'reeii.      Lad  -ral    ;uid 

anterior    valve    sube<|iially    reticulated  all  OT<  'he  poste- 

rior valve  subceiitral,  moderately  acute;  -irdl.-  «-,, \n.-d  with 

minute  BCal66,  POSy-gray  maculated  with  dull  green. 
Len-th   15,  breadth  8  n. ill. 

C/i/fo;/  ( :l.«'hnorl,;to>i)  tjcrlntrij'i  SMITH,  1'.  /.  ^.    1891,    ]».    U<»,    j,|. 

n:;,  i:  (;. 

Only  a  single  specimen  <>('  this  species  wa-  found   l»y    Major    5 
Itury.      The  sculpture  re<-alls  that  of  a  thinihle.      It  i»  a  trifle  coar-er 
on    the   lateral,   especially    aloni:   their   posterior  margins,  than  on 
the  central  areas.     The  dirty  green  spotting  is  also  more  notic, 
on  the  hinder  edges  of  the  valves  than  elsewhere.     (Sin 

I.  M  vrcii.i.ivRAYi  Carpenter,  n.  sp.      Unfigured. 

Shell  elongated,  small,  elevated,  the  purum  sliirlitly  acute,  valve- 
heaked  ;  ashen-hrown  or  pale  ashen,  often  elegantly  painted  with 
lines  or  angular  flames.  Entire  surface  minutely  gran  n  lose  ;  lateral 
areas  scarcely  defined,  having  radiating  wrinkles,  not  very  distinct. 
Mucro  median,  little  elevated.  Interior:  posterior  valve  having 
12-13,  anterior  valve  12-11,  median  valves  1  slit.  Teeth  subacute ; 
eaves  very  conspicuous ;  sinus  wide,  flat,  smooth.  Girdle  cl< 
covered  with  delicate,  subelongated,  strongly  lirate  scales. 

Length  14,  breadth  7  mill.;  divergence  110°. 

Tristan  d'Acunha  (Macgillivray,  Mus.  Cuming,  No.  74,  92)  ;    St. 
Paul's  (Mus.  Ginning,  No.  7). 

The  specimens  from  the  last  locality  have  the  teeth  acute. 

This  shell  has  the  general   aspect  of  Trachydennoti   a/t>u.-<  hut    is 
longer,  not  so  sharp  at  the  ridge,  more  highly  sculptured,  and   tin- 
scales  strongly  lirate.     The  pattern  varies  greatly  in  the  specii 
It  is   nearly  related  to  /.  OHI'M-H*,  and  a  larger  series  of  individuals 
may  prove  them  identical     (Cpr.,  MS.) 

I.  RETICULATUS  Reeve.     PI.  20,  figs.  HI,  17. 

Shell  oblong-ovate  ;   terminal  valves  and  lateral  areas  of 
radiately  ridged  ;    central    areas    rudely    and    closely    reticul;, 
dull  brown  ;  ligament  horny,  rouirh.     i  Heeve.) 

Wei    I 


102  l-<  IIN(>(  HI  I  • 

Chiton  tcj'titi.-*  WMr.  Sown..  Condi.  Illustr.  i'.  01,  according  to 
Reeve. —  Chiton  retimlntu*  Rv.,  Conch.  Icon.  j,l.  ]."">,  fig.  83  (1847). 
— hchnochiton  reticulahis  CIM:..  .!/>'. 

Reeve  states  that  this  is  the  textilis  of  Sowerhy  hut  not  of  Gray, 
and  lie  i-  probably  right,  although  his  own  identification  of  text  ilia 
( iray  is  erroneous.  Carpenter  gives  these  notes  upon  Reeve's  ty pi- 
specimen  :  One  specimen,  which  is  over-colored  and  over-drawn  in 
Reeve's  illustration.  It  looks  to  me  like  a  line  textitin,  as  Sowerby 
seems  to  have  taken  that  species,  but  I  have  no  /<•./•/ ///*  by  me  for 
comparison.  It  is  very  light  brown,  with  little  black  irregular  dots 
which  appear  to  be  adventitious.  Girdle  typically  Isclmoid,  with 
moderate-sized  striated  imbricating  scales.  Fine  radiating  ribs  on 
the  lateral  anas,  very  numerous  on  the  terminal  valves;  honey- 
combed in  the  middle  ;  jugum  very  much  rounded.  Anterior  valve 
with  14,  central  valve  1,  posterior  valve  12  slits;  teeth  sharp;  sinus 
very  broad  and  flat,  not  toothed.  Length  303,  breadth  16  mill. 
(Cpr.) 

Compare  textili*  Gray,  from  which  this  differs  in  coloration  and 
apparently  in  sculpture. 

3.   Group  of  I.  ri**oL 

Small  species  having  longitudinal  riblets  upon  the  central  areas, 
and  continuing  backward  over  the  lateral  areas.  These  are  closely 
allied  to  the  group  of  /.  striolatH*. 

Distribution  :  Mediterranean,  African  and  West  Indian. 

I.  KISSOI  Payraudeau.     PI.  20,  figs.  1-7. 

Sln-11  oblong,  elevated,  the  back  regularly  arched  or  snbcarinated, 
side  slopes  convex.  Surface  longitudinally  1  irate  on  the  intermedi- 
ate, concentrically  on  the  end  valves.  Color  pale  brown-olive,  the 
lateral  areas  and  end  valves  more  or  less  maculated  with  snow-white 
and  In-own. 

The  lateral  areas  are  moderately  raised  and  sculptured  with 
coar.-e.  Hat,  uneven-edged  longitudinal  riblets,  which  are  separated 
by  narrow  punctate  intervals  and  are  frequently  irregular;  under 
a  higher  power  of  the  microscope  the  surface  appears  to  be  min- 
utely punctate,  the  dots  whitish.  The  central  area>  have  cl«»e.  line 
riblets  in  the  same  direction,  somewhat  finer  on  the  dorsal  ridge, 
and  giving  way  to  a  minute  punctation  in  the  region  of  the  beak  of 


HNOCHIT'  [00 

each  valve.    The  umbo  of  the  posterior  val^  ml  ami  : 

eratrly  elevate. I. 

Interior  white ;  >utm-al  plates  raiftll,  -»-p:iratrd  id*-, 

flat  siim-.      Anirrii-r  valve  lia\in-_r  !•"•.  po-in  i..r  valve  Ml 
tral  valves  1  slit  ;   teeth  .-harp;   eftVei  narrow,  .-hurl,  -olid. 

(  ;irdle    covered    with    rl.  -mall,   Btl  ialulale,    in 

scales.      Length   !•"),  breadth  *  mill. 

.!/-  dit(  i  i-'ini'tin  and  A<>  r> 

chiton  rtwot  I'AVI:..  Moll.  Cone,  p.  87,  t. 

PiMi.irn,    Knum.    Moll.    Sicil.   i.   p.   107. — C\ri  i  IIM,  .I«.iiru.    <!«• 
Conchyl.  (2)  iii,  p.  '^2'2  (1«S")J)).— Issr.i.,  Intonio  ai  Chiton  dd    mare 
di  (Jonova,  in  P>iill<'ttim»  MalacologlCO  Italiano,  iii.  p.  ."»,  t.  1,  t 
(1870).— MOFTBBOSATO,  Journ.  de Conchyl.  1*7\  p.   117.— I. 
I)\i  T/..  .\:  DOLLF.,  Moll.  Mar.  Rouss.  p.  495,  L  81,  t'.  10,  11,  12;  t. 
tt'2.  t'.  2. —  r/t.  mriH't/hinii.  CAPKLLINI,  Joimi.  dc  Conchyl.  (*2)   iii,  p. 
325,  t.  12,  f.  1. —  Ck.  inediterraneu*  "Gray   MS.,"    I;  >nch, 

Icon.  t.  23,  f.  ir>7  (1847). 

This  species  is  well  characterized  by  its  flat  close  concentric  rib- 
lets  and  the  sparsely  scattered  snowy  spots  on  the  end  valves  and 
lateral  areas.  The  sculpture  of  the  lateral  areas  is  irregular  and 
variable,  the  riblets  being  ragged-edged  and  occasionally  sul> 
lete,  leaving  the  raised  areas  almost  smooth.  The  C.  />o/ii  Phil,  is 
readily  distinguished  from  this  species  by  its  difft-ivntly  formal 
posterior  insertion  teeth  ;  in  ri**oi  the  posterior  teeth  are  normally 
Ischnoid. 

The  Ch.  mediterraneux  of  Reeve  is  simply  a  synonym  of  the  typi- 
cal form  of  this  species.     The  form   which  Reeve  calls  risso 
Icon.  t.  19,  fig.  122)  is  a  synonym  of  the  variety  meneghinO. 

V&r.meneghinii  Capellini  (pi.  20, figs.  8-10).     Sculpture  stronger, 
the  end  valves  and  lateral  areas  exhibiting  distinct  radiating  stria-. 

Var.  frayill*  Monts.   (Enum.   e  Sinon.).      Smaller  in   si/t\   the 
sculpture  obsolete,  without  trace  of  radiating  stria-. 

I.  PERTUSUS  Reeve.     PL  20,  figs.  18,  1  !>. 

Shell  oblong-ovate,  valves  elevated  in  the  middle,   very   cl 
grooved   throughout,  ridges   of  the  central   areas  thin,  nm\vr_ 
towards  the  umhones,  interstitial  grooves  pricked,  posterior  edge  of 
the  valve  serrated  ;    dark   red,  sprinkled  with  a  tew  minute  white 
dots;    ligament  horny,  very  sparingly    b«'.M-t    \\ith  short    hri.-tli->. 


lui  BCHNOCHITi 

Th»-  pricked  inter-tic,  n  tin-  clo>e-set  ridircs  which    consti- 

one  of  tlu*  distinguishing  features  of  this  species  are  scarcely 

:iihle  without  tlio  lens.     (Rve.) 

Simon's  /*'<///,  Cape  of  Goo<l  II 

C.i  i: .  i     <    >nch.  Icon.  pi.  xvi,  £  88     L847).— -IMfioc&t- 

1    !•!:..   .l/\ 

rpenter*s  notes  from  two  specimena  in  tin-  Cumin-.:  collection 

areas  follow*:  The  liur'iiv  in  Keeve  doe-  nut  rcprc-cnt  it  well.  It 
i-  one  of  the  /•/»'»/  irnmp.  Shell  much  arched,  elevated,  lint  the 
juiruni  rather  blunt,  t'mho  of  posterior  valve  raised,  situated  at 
the  anterior  third  ;  the  -lopr  hehind  it  very  ,-liirhtly  concave,  nearlv 

jht.    <JinlU»  with   Isclinoiil  scales,  but  small,  long,  somewhat 

iinlirieatinir  and  >triated.  Color  oliv:uvou>,  varie«rated.  JiiLral 
area  imt  deiined  from  the  central  areas,  which  are  sculptured  with 
v« TV  numerous  and  line  rather  blunt  liruhe  with  extremely  small 
inter-ii<'-:  <>r  the  >url'ace  ini^lit  he  described  a<  finely  «rniov«  d. 
ThcM-  .-mail  rihlets  are  longitudinal,  very  slightly  «rrai)o.-e,  and  at 
the  diagonal  liordrr  of  the  lateral  areas  become  rupilose,  passing 
on  to  join  with  the  riblets  of  the  latter,  The  lateral  areas  have 
about  '•'  to  12  very  fine  radiating  rihlets  which  are  m::de  i:ran«»e  by 
the  longitudinal  riblets  from  the  central  areas  cro»ini_r  them.  The 
end  valves  have  very  close  and  regular  radiating  rows  of  Drains,  the 
-culpture  bt-inir  very  like  that  of  C'ltrini/ntii*,  but  in  that  species  the 
i-oiic.-ntric  wrinkles  predominate.  The  head  valve-  has  TJ  slits, 
median  1,  posterior  valve  !)  slits.  Teeth  quite  sliarp,  with  lonur  |>ro- 
jectiipj;  eaves,  which  are  not  spongy.  Sinus  broad,  rather  deep,  flat, 
-m. .,,th.  but  deeply  channelled  on  each  side  at  the  inner  has.snfthe 
sutural  plate-.  Terminal  valves  stained  with  brownish-purple  inside. 
:li  :;•_'.  breadth  K'.;  mill.;  divergence  113°. 

I.  i  \:\  HII:«>N«>ITS  C.  ]\.  Adams.      Unfi</n,;  <l. 

Shell  small,  snbeloiiirate.  [  convex,  not  carinated]:  yellow-wliite, 
[the  back]  irregularly  maculated  with  red;  lateral  areas  ribbed,  the 
rib-  n. .diilons:  d«»r-al  area<  [silicate-]  striated;  «;irdle  scaly  [  vel- 
!••  \\i-h-\vhite.  maculated  with  ashen].  Length  1  .'J ,;,  width  7',  mill. 

\danisi:   >V.    Thnnin.*  ninl  r<,,-t<,  Him  (\\\\\\\\\*>v  <. 

Cli  IhronakuC.  P..  Ai>.,  Proo,  BostSoe,  N.  II.  lv 

—  1  .        I      ;,'»lrliifnn)     t'1-iltlii-iniufii*     SnrTTI.W.,     I>eril.   M  i  1 1  lie!  I .    ! 


The  pa--a^cs    in    brack.  -i-    uf    i 
w<»rt  h's  Interpolal  i' 

I.  i  \  1  1  1:1  1  ii  -  Shuttleworth,     I  'iiiiy 

Shell  clliptical-ohluiij,  (-,,nvc\  ;    l.i 

with    whitish;     end    valve-    .-iihcuiicent  rically    HIM  -ah-  and  pun- 
Mt  diiin  valve-  imt  c:i  rinated  ;    c,  ntral    ft] 

impn-sed,  becoming  transversely  cottulftt  nibmloate  at  1 

lateral    areas   suhelevated,    radiately  snh-ulcafe  and  minutely  punc- 

tate-foveolate,    Girdle  unioolored  nil.  dm^-iv  bc-et   with  minute 

flattnird  icalet,      Lrnirtli  I  L\  l.ivadth  H  mill.      >SI,,,tt/w.) 

•SV.   '/  ln,,»  '  .    II  . 

(Ifchnockiton)    A//r/-/////x   Snr'rri,\\.,    hia-n.    n.    Mull,    in 
i.  Mittheil.  1853,  p.  75, 
I  havr  nut  idcntiiicd  this  sju-cii  s,  of  which    Shnttlcwurth    wr. 
I    have    two   specimens.      The   color    i<   an    int<  -nse    l.rick  red,    l.oth 
iinide  and  out.      It  is  allied  to   (  '.  cnjtlirnnntti*  (  '.  H.  Ad.,  lint  ditN-r^ 

abundantly  in  toe  sculpture  and  color,  and   in  the  1<  .->  elun-at.  d 
shell. 


4.     (,'rnnji  of   I. 

Small  species,  apparently  smooth,  hut  under  a  len.-  shuwini:  a 
sculpture  of  longitudinal  rildets  or  lines  of  grannies  on  the  central 
areas,  interrupted  on  the  lateral  areas,  which  arc  niuirlu-niMl  hy 
peculiar  irregular  impressions  (pi.  1*,  tig-.  54,55  .  It  i-  difficult  to 
describe  the  sculpture  of  the  lateral  areas  of  these  >[>••«  it--  :  it  i- 
what  (  'arpenter  called  "  thuinby  "  or  "  pollicaroid." 

Diatribution  :  Antillean  and  I'anarnic 


Sped  i'"  ii'ifh  >•//•/'//' 

I.  STRIOLATUS  Gray.     PI.  20,  figs.  20-24. 

Shell   ohloiig,  moderately  arcln-d,    the    hack  sometime-  distinctly, 
sometimes  scarcely   visibly   keeled;    side  slope-  convex.     SB 
showing  no  sculpture  to  the  naked  eye,  hut  having  the  lateral  : 
moderately     di-tinct.       Color    e\ce--ively    variable    but    generally 

either  olive-green  or  olive-slate  colored  with  white  ur  creamy  t!- 
or  cream-culore<l,  minutely  mottled  with  light  bn»wn.  The  i 
riur  ed^e  of  each  valve  i-  dolled  with  light  and  dark,  form 
sutural  articulation. 


106  IN.  .rim 

Lateral  areas  slightly  raised,  sculptured  Longitudinally  with   //«/•- 
row  zi'/:<i<i  i/i-woe*,  the  eleva\'«>n*  l»iu-,'t  n  tin  m  (Int.  «//</  der  « 

to  be  »io.</    munife/if  pHxfii/nt'.   the   ptiMules  whitish. 
nil    areas    coven  d     with    <m    CXCCSSlVely  ////'.    ('/<>••<>'    (jiiium 

/licit  be<'tnnr.«  *tiyht/y  <•«*//•>•/  /•  t»u;i,-<l  '  where  the 

•_li-it<lmtl/y    brnmif    nt>  <•</«/  info    Ion  f/ifniliim/    i-inr."  'jicitKi  (i 
///•«//'•   <ij,i  to   the  pi'  in-  1,  especially  to  the  part  Iving  at  and 

iiiuii.Mliat.lv  in  front  of  the  diagonal  line.     Knd  valves  having  con- 
centric /iir/aL  and  a  minute  granulation,  like  the  lateral 

areas;    |>o>terior  valve  having  a  moderately  elevated,  central  unilio, 

rior  >loj.c  concave.      Interior  liirht  «rray-l)lue  or  white  :  ani> 
valve  with  !>,  central  valve  1,  po>teri«,r  valve  !»  slits.     Teeth  .-mooth, 
>harp.      Maves  narrow,  solid;    sutural    plates   wliiti.-h,    rather  wide 
and  low:  sinus  Hat,  angular. 

Girdle  whitish  clouded  with  blue,  or  blue  marbled   with   white, 
generally  having  some  small  yellow  or  orange  flecks.     It  is  densely 
covered  with  imbricating,  deeply  striated  scales.     (PI.  20,  fig.  24.) 
Length  14  to  15,  breadth  8  mill. 

St.  Thom<t- 


GRAY,   Specil.   Zool.   p.    «    (1828).—  KI:I:\  i  , 
Conch.  Icon.  t.  22,  f.  144. 

The  coloring  of  this  species  is  extremely  variable,  and  the  sculpt- 
ure, while  it  is  unmistakable  when  seen  under  a  sufficiently  hi^h 
I  lower,  still  varies  considerably.  The  side  areas  and  end  valves 
are  generally  sculptured  with  the  concentric  zigzag  grooves 
described  above  (fig.  23)  ;  but  occasionally  these  become  &o  irregular 
and  broken  that  the  surface  appears  coarsely  granulous  or  scaly. 
The  West  COUM  species  di*par  8owb.  and  utl<nn*ii  Cpr..  afl 
well  as  the  /V,>-M*X  of  Sowerby,  all  belong  to  the  #fi'i<t/(itnx  ^rouj), 
and  are  closely  allied  in  sculpture.  There  are  also  a  number  of 
described  West  Indian  Ischiiochitons  which  seem  to  be  either  mere 
>ynonyms  of  /.  >//W<//"*,  or  closely  allied  forms,  the  «  xact  status 
of  which  it  is  (piite  impossible  to  fix  with  certainty  until  the  origi- 
nal types  can  be  examined  by  a  competent  person,  thoroughly 
ar«|ii:iinted  with  the  Mibject.  The  original  descriptions  of  these 
forms  here  follow. 

C.  Bquamuloetu  C,  1»-  Adams,  shell  olivaceous,  ornamented  with 
a  pale  green  dorsal  line;  lateral  areas  covered  with  prostrate 


UN."  111  1  |<>, 

unequal  ICaleS;    n-ntral  area!  mark  -in-  1.,  ill  ill  the    middi' 
striale  ;  girdle  I""  illernalt  i 

Length  17    breadth  Hi  mill.     <  Ad.) 


Chiton  .tiiininiHlnxti*  .\|...  ProC,   I'  Ili-t.  ii.  : 

—  C.    :          guamu/Mu*  SHUTTLW,  I1.,  i  n.  Mittln-i: 
Thia  ia  unquestionably  the  same  form  I  havr  d<  ~nil><  .1  ab 

The  name  AtfOmtt&MU*  will  therefore  h»-e..mr  ;i 


C.    lutulutti*    Shutllw.       Shell    small,    elliptical-ovate. 
narrower   in    t'ront  ;    dull    olivaceous  spotted    with    wliih-;  tcrniiiiiil 

valves  impressed-punctate,  toward  the  margina  irregularly  concen- 
trically Buboostulate  ;  jugum  not  keeled;  di»i>:il  ana-  tim-lv  and 
regularly  imprCSSed-punctate,  and  touard  the  niai'-iii-  th'Miondv 
and  irregularly  transversely  j)lieatulate.  (Jirdle  olivai-nm-  and 
spotted  with  white,  the  >e;,les  small,  flattened,  iml)rieat<-d.  L.'ii-jth 
1-J,  width  ^  mill.  (Mnttfw.') 

I  '     '  •   I 

Chiton  (  I«rh>i<>('hit<»i)  lutu/<ttn«  SuriTl.w.,  /.  r.  p.  7«'».  1 

This  was  described  from  a  single  specimen,  and  slid  to  ditfl-r 
from  C.  xfy////m///Wx/x  in  being  narrower  with  more  regular  sculpture. 
I  have  no  hesitation  in  considering  it  an  absolute  synonym  of  /. 
striolatus. 

C.   carrifaorum    (Cpr.)  Smith.     (PI.    L'U,    f]gi.    26,    26  ,      >hell 
lengthened-oval,  scarcely  carinated,  variedly  painted,  grayish-olive, 
white,  reddish  and  olivaceous,  or  purple,  sometimes  hlarki.-h   with 
white  markings;  end  valves  concentrically  and   roughly  gn.' 
striate  or  scaly,  central  areas  ornamented  with  delicate,  curved. 
flexuous,  granose    lira1;    lateral    areas   roughly    <rrano-c    ..r    -<-aly. 
Posterior  valve  slightly  concave  behind  the  central   aj»e\.     <iiidle 
minutely   scaly,   covered    with   elongate  oval   -cales  pa'e  i 
tessellated   with  diluted  black.      Length  '27,  diam.  !•  mill. 

St.  TttoHi'i*;   J 


The  above  appears  to  be  a   manuscript    name   attached   to  S] 
mens  in  Cuming's  collection    which    are   identical    with    tew  shelU 
from    Fernando    Nonmha.     The    color  is  very  variable,  >.  ' 
mens,   when    viewed   from  a  distance    of  twelve   indie-.  app«-aring 
olive-grav,   speckled   with    white;    others   are   of    a    pinki-h    en-am 
color  speckled    with    red  or  blotched  along  the;  >id«  -  in  front  "f  tbe 


108  ISCIIN'M  mi  • 

lateral  areas  with  black,  as  in  some  of  the  specimens  from  F» -rnando 
Noronha.  Tin-  granules  or  scales  of  the  lateral  area  and  on  tin- 
front  and  posterior  valves  are  peculiarly  Hat  and  arc  somewhat 
tran>versely  arranged  on  the  former  and  concentrically  on  the  lat- 
ter. The  central  areas  are  finely  punctured  along  the  center,  and 
become  more  and  more  coarsely  grnnoM-ly  lirate  as  the  sides  are 
approached.  One  example  is  almost  entirely  reddi.-h  purple,  and 
others  are  blackish  with  a  broad  pallid  stripe  down  the  middle  from 
end  to  end.  (Smith.) 

('/litnn  (Itcknochiton)  caribbatorum  (Yi:.,  J/.s'..  SMITH,  .loiirn. 
Linn.  8oc,  I.  'iid.,  \x,  p.  4(.>o',  t.  .'{(),  f.  ~>,  5a. 

The  dimeiiHons  given  hy  Srnitli  may  possibly  he  a  mistake,  for  the 
iark  on  his  plate  is  only  I-')'  mill.  long.  In  other  respects  the 
description  and  figures  indicate  no  tangible  points  of  difference 
from  the  /.  .<t,'it,I<itu«. 

<  arpenter's  original  description  of  carribceorum  is  before  me, 
and  it  is  an  excellent  word  picture  of  some  of  the  St.  Thomas  >pec- 
imens  of  *t, -io/iit u*.  It  is  worthy  of  note  that  Carpenter  recogni/ed 
the  specific  identity  of  >7/-/V>A////x,  ciiriblm-nrinn,  j<tnmi<-i-i,si.«  and 
."ijii'inin/oxi*,  in  one  of  his  later  notes. 

/.(/  oaribbasorum  var.)  jamaicensis  Cpr.    Smaller  than  <-n,-ibb(K- 

-.  the  lateral  areas  scarcely  defined. 
Length  7-j,  hreadth  4,  alt.  1  i  mill.     Habitat,  Jamaica. 

/.  (t  jammcentis)  viri<Hor  Cpr.      Larger   than    /.   jnm 

i.  variously  maenlated  with  olive;  interior:  posterior  valve 
having  x,  anterior  !»,  central  valves  1  slit.  Length  11  !,  hrea«lth  7 
mill.:  di\n  j»  IK  »•  100°.  There  is  no  character  but  size  and  color 
by  which  this  solitary  specimen  can  be  distinguished  from  the 
Jamaican  -hells.  (  (  )//•.) 

The  sp»cific  identity  of  the<e  two  .1/X  forms  with  /.  N/,vV//>//>- was 
COncede.l  I iy  (  'urpenter. 

Lfuniculahu  Carpenter.  Shell  small,  strongly  oval,  suhelevated, 
the  jii'jnm  little  acute:  pale  ashen,  ochraceous  or  olivaceous  varie- 
gated: mucro  central,  moderately  prominent.  Kntire  surface 
wrinkh-d  and  minutely  pitted:  wrinkles  >nhregul:»r.  nearly  j.aral- 
lel  with  the  d..r-al  rid_re  on  the  central  areas,  ahout  1  x  on  each  >ide, 
Obsolete  toward  the  jugum  j  the  moderately  distinctly  defined  lat- 
M  and  the  end  valves  undulated  and  having  sul)ohsolete 
radiating  liruhe.  Interior:  posterior  valve  with  7-i>,  anterior  valve 


BNO4  HOT 

7    in.   central    valve-    I     -lit.      'I 

wide,  ll:ii.      (  iirdle  lurid-lied  \\  ith  \ . 

tened  M-ales.      Length   10,  width  .')  mill.;   di\< 

(.'iKi'l.l/nllf,,-   .   Mil       ' 

(  >ne  specimen  Is  of  a  pale  yellowish  tint  flight]}  -I  \\iih  :i 

brighter   color;    another    i-    in  .iv  a-hy  and  \vil  li  t  lie  \  : 
pale    olive.      h    has    stronger    .-culpture   than    /.   <•//, •//,/,*/•»,,•///;/. 
ruguhe    rising  tij)    like  close    rungs    in  a    rope-ladder,  and    denta' 
the  sutures.      (  ( '/»-.') 

The   above    deseri|>t ion,    from    Carpenter1!    .!/>.    defioei    a     fonn 
which    will  probably   prove  to   he  a   variety  of  T.cwil 
\\hieh  species  Carpenter,  at  a  later  date,  united  it. 

I.  PBUINOSU8  Could.     IM.  LM,  fitrs.  27,  28. 

Shell  small,  elongated,  nearly  elliptical,  convexly  elevated, 
earinate.  or  rather  somewhat  doubly  carimite  alon^  tlie  hack  :  §or« 
t'aee  generally  covered  with  microscopic  |)iinetnres,  ai-raiiLrfd  in 
lo/.'.-ni:e.  Lateral  areas  very  slightly  rair-cd,  and  longitudinally 
imbricate-sulcate ;  central  areas  with  faint  line  wth  and 

punctures  in  quincunx ;    anterior  valve  concentrically  .-triate,  not 
punctate;   posterior    valve    slightly    nmbonate,    and    rn»-> ed    l»y    a 
Iran-verse  ridge,  behind  which  it  is  concentrically  Mriate.      1 
frosted  or  mottled  with  dark   brown,  ash,  purple,  green.  Are.      Mar- 
gin minutely  granulated,  so  as  to  look  hoary.     (Old.) 

"Some  specimens  are  of  a  uniform  pale  green.     Margin  chmdrd 
with  dark  green;  some  had  two  or  three  distinct,  white  blotch. 
the  sixth   valve,  the  rest  of  the  shell  being  olive-green,  with   a  line 
of  faint  green  along  middle  of  back  ;  another  had  the  ground-colour 
a  clear  olive,  three  dark  brown  spots  bordered  with  white  <>n  each 
side  of  posterior  margin  of  valves,  a  row  of  similar  spot-  surround- 
ing the  terminal  valves  just  above  insertion,  and  the  whole  sin 
sparsely  and  irregularly  spotted  in  the  same  way  nt  a 

delicately  mottled  a-pect.  A  fourth  variety  wa>  of  a  uniform  dark 
rosr-oilor.  and  the  margin  clouded  with  dark  red  band<.  Inter- 
nally it  was  dark  red  or  rosy  along  the  middle,  and  dull  yellow 
toward-  the  sides.  All  the  other  varie.  i  greenish 

hue  internally."     (Cnnfli.  i,,  <;!<!.  > 

Length  17 '.  breadth  *  ;  mill. 

Off  /•''"•'  •s'""/"   OrVft  H'"  •/"""''•",  ""  stone-  in  'J  or  :i  t'ms. 


1  111  tSCHNCH  IIITON. 

-"v(;M,.   I',,  Soc,  N.  II.   ii.  p.  144,  July  ls4(J: 

otia  Conch,   p.  5,  242;    I  .  S,    ExpL    Exped.  p.  316,   t  419.— 

iiir.iMM,  P..lyplax.  Cap   Horn,  p.  141. — hchnochiton pruino- 
CPB,  .V>.  p.  77.  103. 

Carpenter  seems  to  consider  this  the  same  as  mr'iblxtnm,,,  and 
'  iht* ;   hut   the  specimen  before  me  is  too  worn  to  enable  me  to 
decide. 

1.  1:1  «,!  LATU8  S,,werhy.      PI.  21.  fi--.  ~t'\-~n  . 

Shell  ohlon.tr,  rather  smooth,  olivaceous  varied  with  white;  front 
valve,  lateral  areas  and  posterior  valve  concentrically  unduh;t.  Iv 
wrinkled:  central  areas  smooth,  wrinkled  at  the  margins.  Length 
•Jo.  breadth  10  mill.  Girdle  granose.  (Soivb.} 

J'm, -tn  r»i-ti->r<>  and  Inner  John*  Jil.,  Centrnl  Anit.i'i'-n,  under 
Btonefl  :it  h»w  water. 

rliltnn  rtiiiiil.tttt*  Sown.,  P.  Z.  S.  1832,  p.  58;  Concl.ol.  Illu^tr.  t. 
!_'.  78,  1  I-.  144  ;  Heechey's  Voyage,  Zool.  p.  \r>o,  pi.  41,  fig.  18.— 
REEVE,  Conch.  Icon.  t.  19,  f.  118;  t.  20,  f.  128,  13:}.— /W/,,,W//7oy, 
1-niintnfn*  <  'i'i:.,  MS. 

(  arjienter  describes  the  interior  and  girdle  from  the  type  speci- 
ii, .11.  tlni-:  Posterior  and  anterior  valves  having  9,  central  valves 
1  slit;  teeth  solid  ;  eaves  moderate ;  sinus  \\ide.  Hat.  Girdle  closely 

imhricalcd  with  moderate  sized  solid  scales,  scarcely  striated. 

It  is  very  like  drinlnln*  but  havini:  stronger  sculpture.  It  goes 
through  all  the  color  variations  of  lonijicijnilxt.  The  >cah-s  M-I-III  to 
he  smooth,  but  here  and  there  are  slight  striolations  from  the  dried 
skin. 

I.  c.\  i  i:\ri.ATUS  Sowerhy.     PI.  21,  figs.  47,  48. 

Shell  lonir  and  narrow,  elevated,  arched,  the  jugiun  rounded. 
( iirdle  smooth,  broad,  thin,  with  imbricatini:  striated  scales.  Muero 
central,  elevated,  the  posterior  slope  >..nn  what  concave.  Central 
:n. -a-  sculptured  with  very  close  parallel  liruhe,  which  pa.-s  into 
wrinkles  on  the  lateral  area<.  which  ai'e  -wolleii.  Mud  valve-  con- 
centrically wrinkled.  Interior:  posterior  valve  having  I  <>,  «-«-ntral 
1,  anterior  valve  '.»  >lit>;  teeth  huiir,  sharp,  thin  ;  eaves  moderate, 
not  loi)Lr,  but  well  develope»l  ;  not  spongy.  Sinus  broad,  deep, 
Miiooth.  channelled.  Length  17,  breadth  7  mill.:  divergence  about 

L02  .       ' 

Inn,  /'    /,'.//,,>    I.*I,i ml.    I9,  ,-tl. 


I-'  ll\'.<  III  111 

•WB.,  I'.  /  nch,  in,. 

l  15,     REEVE,  <  onch,  [con,  t.  •_'«.,  t:  180.     / 

<    ri:.    MS. 

The  single  specimen  before  me  is  \vhiii~h,  I  UJH, 

brown.    tli.-   girdle    a-hen-hluMi.      The    >culptui. 

more  like  thai   «.!'   /.  th  in/.ii,.  ..,,,|  adorn      < 

thing  else,  having  exactly  the  same  pattern,  but  not  «pntc- 

The  girdle  has  conspicuously  Mriated  scale-. 


The  following  gpeciee  were  referred  liv  Carpenter  t,,  €i  L«-|«i«l<t- 
plrunis,"  but  they  arc  closely  allied  to  the  j»n  up. 

I.  DHJPAB  Sowerby.     PI.  is,  figg.  17,  48. 

Shell  oval,  -niooth,  asln-ii  varied  with    whitish    and    Mack.      < 
tral    ai-cas   smooth,    posteriorly    longitudinally  suloulcatr  :   ant. 
vaK'c,  lateral  areas,  and  |>osterior  area  of  the  posterior  valve  uianu- 
lous.     Girdle  grunosc.     Length  25,  breadth  12i  mill.     (&•> 

Inland  Saboga,  Bay  of  l*tununn,  under  .-tone.-  on  the  shore. 

Chiton  d'i*i«tr  SIJY.,  T.  /.  S.  1832,  p.  58;  Conchol.    Illustr.   f 
—  KKI-IVK,  (1onch.   Icon.    t.    18,    f.    96.  —  Not    7,svA//o,  -,/,/,,. 
Cai-penter  MS.  —  Chiton  jir<>/»-iit#  K.KKVI-:,  Condi.    Icon.   f.    lol.  —  C. 
picus  KKKVK,  Condi.  Icon.  t.  25,  f.  121. 

The  name  has  been  suggested  by  the  circnm-tanee  of  the  central 
areas  bein.ir  quite  smooth,  while  the  lateral  areas  are  covered  with 
granules,  i  (1.  B.  Sowerby.') 

The  description  given  by  Sowerby  differs  entirely  from  the  spe- 
cies which  1  take  to  be  the  /.Wn/o/v/Js/</  <li.^,<ir  of  Carpeiit.  r*|  !/>.. 
and  indicates  a  form  very  similar  to  Carpenter's  L.  <nlnui^ii. 

(  'arpeiiter  writes  of  the  type  of  C.  />r»/>riti*  Rv.  as  follows  :    One 
specimen,  smashed;  "  West  Coast  of  America."  I>r.  A.  Sinclair,  K. 
N.     This  is  exactly   like  the  L''jii'l»/i/rni-ii*  ii;.«/»ir,    havin- 
lar--.\   smooth   scales.     Reeve's  C.  pictu  i>  also  said  by  Cpr.  to  be  a 
synonym  for  /.  <li.-j><ir. 

I.  AI.AM-II  Cai-penter.      1*1.  Is,  figs.  ."il.  ")•_'.  68,  "»  1. 

Shell  resembling  A.  '//•*/""'  -  Pal"  red-brown,  irregularly  streaked 
and  maculated  with  darker,  sometimes  ornamented  with  white  spots 
at  the  diagonal  region.  ,  I  ugiim  scarcely  acute  ;  central  areas  and 
terminal  valve>  conspicuously  granuloi;-  :  ftreafl  irregularly 


Ill'  KCHNOCHITON, 

uarted.    the    warts    lohed.      Mucro    anterior,    slightly 
Interior    having    tin-  central  valve  with  1  slit,  end  valves  8-10  slit-. 
ii  acute;  sinus  flat,  very  wide.     (iirdle  imhrieately 
Length  !•">.  breadth  7'  mill.;  divergence   110".     <  (  )/r.) 

J'ltHIIIH'1. 


danuti  CIM:..   I*.  /.  s.   1st;:;,   p.  24.— 
adatnsi*  CPB.,  1'.  /.  S.  1866,  p.  'J74. 

Tlie  -hells  which  I  have  drawn  in  figs.  .">1  -.">.">  of  pi.  18,  seem  to 
me  to  belong  to  this  species  rather  than  to  /.  <l!.<]>ar.  They  are 
described  In-low.  It  must  he  understood  that  the  more  minute 
sculpture  can  be  seen  only  under  a  compound  ini<To>mpr  <>r  a  very 

Mul    lellS. 

The  shell  is  oval,  rather  low,  the  jugum  rounded.  >ide->lop.  s 
nearlv  straight.  Color  dark  olive  mottled  with  lighter,  or  having 
large  whitish  tracts  on  some  valves;  the  interior  light  blue,  sutuml 
l>l<ite.-<  u'liite.  The  central  areas  are  closely  sculptured  with  very 
minute  pointed  whitish  granules,  arranged  in  oblique  lines  at  the 
juiriini  (fig.  52)  but  toward  the  sides  or  pleura  a  system  of  shallow 
grooves  with  graniilon<  inter-ridges  curve  forward  from  the  diagonal 
line,  as  shown  in  fig.  f>4,  and  at  the  left  side  of  fig.  of).  The  lateral 
areas  and  terminal  valves  have  a  coarsely  reticulated  pattern, 
formed  by  impressed  zigzag  or  irregularly  lobed  impressions,  over 
which  a  tine  granulation  extends  (h'g.  oo.) 

The  interior  has  8-10  slits  in  the  posterior  valve,  1  in  the  inter- 
mediate valves  (fig.  .">:]).  Teeth  sharp,  smooth  ;  eaves  very  narrow. 
The  -jirdle  was  denuded  of  nearly  all  of  its  scales  in  both  of  the 
imens  before  me,  but  such  as  remain  are  large,  solid. 

Length  14,  breadth  8-]  mill. 

I.  TI:M  D9CULPTU8  Carpenter.       l'nfnjnr«1. 

Shell  similar  to  I,.  «  <l#n  /.</'/;  olivaceous,  minutely  variegated  with 

paler  and  darker  color.      Kntire  surface  minutely  granulose  :   lateral 

areas  scarcely  defined  ;  suture-  spotted  with  white:  mucro  anterior. 

rather  conspicuous,  the  slope  behind  it  com-avr.      Interior  a>  in  /.. 

'/ir.) 

Panama, 

Chil'in  ili^mr  ('.  H.  A  I).,  Cat.  Panam.Sh.no.  373l  part   .  —  /..  />i'ln- 
kU  <'ri:..  P.  Z.  8.  18    •'.  p.  -J7-"). 

A  variety  is  paler,  tinged  with  rufous  at  the  jugum. 


l-<    I  IN.  H    III  I 


The  outside  of  this  shell  so  much  iv-nnMe-  id. 

i/»»/-rs//  that  specimen-  may  have  ln-«  ii  distributed  m  <i 

Very  few  individual-  \\  «•  i  v  found. 

on  the  type  .-pecimeii,  pr.ih.-iSily  from  0116   of  tin-   other  In 

tlieonlv    place    in    \\liidi    tliev    lit-    ///    *ifn,    tliev    are  <|uite  MiiM,,tli. 

I.  B08EUB  Bowerbj.     IM.  21,  figs,  I'.'.  •'>". 

Shell  ovate  oblong,   siiHM.tli.    roseate;   back   rounded;   front  \, 
and  lateral  areas  of  the    intermediate    valves  loiigit  mi  inally.  cent  ral 

areas  transversely  sulcate  ;  posterior  valve  with  ctntral  ap 

eentrieallv  sulcate.      Len-'tli   1  7  '  -,  hrcadtli  7  '   mill.      fX 
/.  nf  J'/titu  i  (  'iiniinu  )  ;   i'<i-ii<iii<lo   Noronha  (Chsdlei 

r<  rn  i  l.radley,  in  Mus.  Yale  College.) 

r//.  rwetw'SoWB.,   I*.  /.  S.  l,s:}2,  p.  58;  Conr-h.  Illustr.,  f.  1  I.— 

REEVE,  Con  ck  Icon.,  t  25,  f.  119.  —  DESK,  in  Lam.,  An.  s,  \' 

vii.  p.  4!»s  i  not   Cli'ifmi  rntrn*    lilainville,  Diet.  St«.   Nat.   xxxvi,   p. 

."».">:>.  is-j.")f  a  species  of  Acanthochiton).  —  l*<-lino<-liit<>,>   ,-,,*•  »/.<  < 

.1/N.  —  I.«rhiiorh!t<m  boof/ii   HADDOX,  Chall.   Kep.,    Pulyphtr.,   j».    \~t, 

(1886.) 

There  is  not  the  shadow  of  an  excuse  for  the  change  of  name  made 
liy  ETaddon,  as  Blainville'a  prior  C.roseus  belongs  to  a  -em:-  uni- 
versally admitted  to  be  distinct.  The  west  coast  locality  is  doulited 
by  lladdon,  but  it  is  supported  by  specimens  in  the  Yale  College 
collection. 

(  'arpenter  gives  the  following  notes  on  this  species  :  Valves  and 
plates  very  thin,  snhdiaphanoiis;  mucro  median,  little  elevated. 
Interior:  post.  v.  with  8,  central  v.  1,  ant.  v.  11  slits;  teeth  very 
acute;  eaves  very  slender,  moderately  projecting  :  sinus  large,  Hat, 
high,  scarcely  laminate;  sutural  plates  small,  subtriangular.  (  iirdle 
imbricated  with  minute  solid,  sim>»f/i  scales,  with  bristles  intercalated 
at  the  margin.  The  sutural  lamina-  are  as  .-mall  as  in  /,>/>!»<  ; 
an<l  look  like  a  mere  prolongation  of  the  in.-ertion  plate-  round  the 
comer.  The  scales  though  normally  shaped  and  arranged,  are  SO 
minute  that  Deshayes  placed  the  species  in  the  Tonicioid  group. 

lladdon  writes  of  J.  row  •//.<  (undei-  the  name  /.  bn<njii  i,  as  toll 

The  locality  attributed,  on  the  authority  of  (  'inning,  to  tlii- 
made  the  identification  with  it  of  a  Chiton  from  1-Yrnandn  Noronha 
very  doubtful  ;   a  shallow-water  \asnot  likely  to  live  in  both 

the  Atlantic  oil'  IJra/il  and  in  the    Pacific  nil'  \\  •  -;  0  lombia,   \\illi 
8 


114  1-rilXoriHT' 

the  whole  breadth  of  South  America  between.  That  tlie  Chalk-Direr 
specimen  is  identical  with  the  British  Mu.-emn  specimens  is  beyond 
doubt.  May  not  the  difficulty  lind  solution  in  the  fact  that  the  "I. 
of  Plata,"  as  it  stands  on  ( 'inning's  tablet  in  the  British  Museum, 
and  to  which  Sowerby  (Joe.  cit.)  addt  d  "W.  ( 'olumbia"  is  really  some 
island  in  the  estuary  of  La  Plata? 

The  above  criticism  was  iirst  suggested  to  me  by  the  Rev.  K. 
Boog  Watson,  to  whom  it  gives  me  Lrreat  pleasure  to  dedicate  this 
species. 

The  single  specimen  in  the  collection  is  of  a  pink  color  mottled 
with  creamy  yellow,  with  an  obscure  yellow  line  along  the  jugmu, 
and  with  a  pale  spot  on  each  side  of  the  line  on  severed  valves: 
there  are  also  several  irregular  dark  patches;  the  posterior  valve  is 
deep-rose  below  the  umbo.  The  girdle  is  mottled  brown  and  white, 
there  being  a  white  patch  sit  the  junction  of  each  valve. 

The  shell  is  long,  narrow,  and  arched,  anterior  and  posterior 
valves  with  fine  concentric  ridges  ;  the  umbo  of  the  latter  is  prom- 
inent. The  intermediate  valves  are  apparently  smooth,  but  really 
with  extremely  delicate  longitudinal  strire;  the  lateral  areas  are 
characterized  by  wide  ridges.  The  ligament  has  stout,  tall, 
imbricate  scales. 

The  three  specimens  of  this  species  in  the  British  Museum  are 
pink  and  only  slightly  flecked  with  white,  no  black  or  brown  spots, 
and  in  two  of  them  the  central  areas  have  concentric  lines  like 
those  of  the  lateral  areas. 

o.   Qroup  of  I.  pwictulatissimus. 

Small  species,  having  the  central  and  lateral  areas  closely  and 
minutely  granulated.  No  riblets.  West  Indies  and  South  Ameri- 
can coasts. 

I.  i-Ai-iLLOSUS  C.  B.  Adams.     PI.  21,  figs.  40,  41. 

Shell  small,  oval,  carinated  on  the  back,  the  side  slopes  slightly 
convex;  surface  not  divided  into  distinct  areas,  apparently  smooth, 
but  under  a  strong  lens  seen  to  be  closely  and  evenly  granulated 
throughout;  color  whitish,  closely  mottled  with  olive-green;  or 
olive-green  or  olive-brown,  with  or  without  snow-white  spots. 

The  lateral  an-a<  are  not  raised,  and  are  sculptured  precisely  like 
the  central  areas,  from  which  they  are  defined  simply  by  an  incon- 
spicuous diagonal  ridge.  The  posterior  valve  is  moderately  eleva- 
ted, the  umbo  central,  rather  acute,  posterior  slope  concave. 


UNO,    IN  i. 

Interior  \\hili-h  ;    :uiti-ri«>r  valve  bavin  itral     I  ,    . 

valve  !»  >lils;    teeth  .-harp,  liiin  :in<l  .-inonili  ;    . 
(  lirdle  naiTo\\ ,  alternately  olive  In-own  and  \\  In 

\vr\  minute,  imbricating  striated  .-rule-. 

Length  -S',  breadth  .">  mill. 

Lengtfc  -V.  breadth  •>    mill. 

JuiH'iini  (Adams  i  ;    Murt-n,  X»  \<ni<>    l\<u  //,/»/  A 
llrmpliill). 

Chiton papillosus Av.<  PI-.H-.   ii.,.-t.  >.»<-.  N.   II.   i^i:>.  [..!». — C. 

^opi^/oatw  SHUTTLW.  Hern.  Mitthcil.  l-s">-'),  p.  77.-  / 
l»il>il!n«u«  DAI. i.,  (atal.  Mar.  Moll.  S.-K.  U.  S.,  in   Hull.  :J7,  I 
Nat.  Mus.,  p.  17L'. 

This  is  the  smallest  of  our  Florida  or  West  Indian  I-rlmoid-.  It 
lias  much  the  same  sculpture  as  the  small  Leptochitons,  being  uni- 
formly granulated  and  having  the  lateral  areas  very  indistinctly 
defined.  It  is  readily  known  from  other  Ischnochitons  by  these 
characters.  The  original  description  is  as  follows : 

Shell  small,  wide ;  greenish,  closely  maculated  with  whitish  and 
black;  papillose;  areas  separated  by  a  slender  riblet;  girdle  very 
finely  scaly,  alternately  greenish  and  white. 

Length  5'25,  breadth  3'25  mill. 

I.  ITNCTCJLATISSIMUS  Sowerby.     PI.  21,  figs,  oo- 

Shell  oval,  moderately  elevated,  the  dorsal  rid^u  bluntly  angular, 
side  slopes  nearly  straight.  Surface  apparently  smooth,  but  seen 
under  a  lens  to  be  minutely  and  evenly  granulated  all  over.  Lat- 
eral areas  ill-detined.  Flesh  colored,  speckled  or  dotted  all  over 
with  light  brown,  and  often  maculated  on  some  of  the  valves  or 
along  the  dorsal  ridge  with  dark  brown. 

Lateral  areas  demarcated  by  a  very  low  and  obtuse  ridge,  obsoletely 
sculptured  by  the  intersection  of  two  series  of  obliquely  radiating 
curved  impressed  lines;  central  areas  similarly  sculptured  by 
obliquely  longitudinal  lines.  Umbo  of  posterior  valve  in  front  ot' 
the  middle,  the  posterior  slope  concave.  Interior  bine-white,  having 
9-12  slits  in  the  end  valves,  1  in  the  median  valves;  to-ih  acute: 
eaves  moderate  ;  sinus  wide,  flat.  Gird!.  1  with  -olid,  flat- 

tened, striated  imbricating  scales.      Length  17,  breadth  Id  mill. 

Bay*  of  Callao,  Mexill<me«,  Ljiufj" 
on  dead  shells,  6-10  fins. 


116  ISCHNHCIIIT.  .\. 

Ch.  /miirtu/titi*#tiHHit  Sow r,.,  P.  Z.  S.  1832,  p.  58  ;  Conch.  Illustr. 
f.  9,  26;  Moll.  Beechey's  Voyage  p.  14!>,  t.  40,  f.  3,  3.— RKKVI:, 
Conch.  Icon.  t.  20,  f.  129. 

Tiic  typical  form  of  this  species  is  descrihed  ahove,  and  figured 
on  my  plate.  It  is  characterized  by  the  almost  effaced  but  even 
granulation,  which  is  the  same  on  both  central  and  lateral  areas, 
although  differing  in  direction  ;  by  the  minutely  freckled  color  pat- 
tern, etc. 

Sowcrhy  mentions  a  white  variety  with  a  black  border  and  some- 
what varied  with  black.  This  form  I  have  not  seen.  It  has  been 
illustrated  by  the  figures  in  Captain  Beechey's  Voyage,  H.  ^1.  S. 
'Blossom,'  and  fig.  9  of  the  Conchological  Illustrations.  The  latter 
figure  I  have  copied  on  my  plate. 

I.  IMITATOR  Smith.     PL  21,  figs.  29-34. 

Shell  elongate-ovate,  moderately  elevated,  subangularly  arched  at 
the  middle,  dirty  white.  Valves  narrow,  with  a  single  notch  on 
each  side,  exhibiting  small,  slightly  raised  lateral  areas,  which 
towards  the  margin  have  a  few  transverse  strong  grooves  or  marks 
of  growth.  Front  margin  sloping  very  slightly  on  each  side  from 
the  middle  in  a  posterior  direction  ;  hind  margin  straight.  Sculpt- 
ure consisting  of  close  flat  granulation,  exhibiting  a  somewhat 
serial  arrangement.  Lamina  of  insertion  [sutural  plates]  very  thin, 
with  a  wide  sinus  between  them.  Anterior  valve  sculptured  like 
the  others,  with  fourteen  fissures  within,  the  thirteen  teeth  between 
them  being  sharp  and  straight  edged.  Posterior  valve  with  a  cen- 
tral mucro,  from  which  there  is  a  faint  ridge  on  each  side  to  the  lat- 
eral extremity,  also  marked  with  concentric  lines  of  growth  at 
intervals  and  with  the  inner  marginal  fissures  twelve  in  number. 
Scales  of  the  mantle  minute,  imbricating,  ovate,  arranged  length- 
wise ;  under  the  microscope  they  appear  very  coarsely  transversely 
grooved.  Length  11  mill.;  diam.  of  fourth  valve  f>  mill.  (Smith.') 

Tom  Bay,  Patin/ntiln,  on  the  shore. 

Ch.  (Isrhnor/nt,,,,  )  unitotor  E.  A.  SMITH.  P.  /.  S.  1881,  p.  35,  t. 
4,  f.  13. 

6.    Groii/i  i if  1.  nun i it  a*. 

Surface  evenly,  minutely  granulated,  the  lateral  areas  having 
radiating  riblets.  (iinlle  scale.-  nearly  -niooth.  .Japan,  etc. 


BNOCHTP  117 

[.  COMPTUS  <  "Mild. 

Shell  small,  thin,  cllipt  ical  ;   Lrn-.-n  ,,r  ~r;iH,  t.    Ci  •.•.|u«-nt  1  y 
(l(ittc<l  or  maculated  with  \\hiti-h  or  yellow.      Valves  -ln.rt,  tic 
valves    radiatcly    riblx-d   and   punctate;   central  area!  qtllDI 

punctate.     Lateral  areas  elevated  and  sculptim  d  \\ith    I 

ting    grooves.       Interior    given,       (iirdle    narrow,   imhrie;it.-d    with 
small  elongate*!  grooved  scales.      Length  1  .">,  diani.  10  mill.     <  Old.) 
Ootinut,  J'l/xtn  ;    llnn'm  uml  /,/'//- A'///  /x.  /Slim;,. 

C.  (Leptoehiton)  wnn/itn*  (»<>I:M>,  I'roc.  Host.  Soc.  N.  II.  vii,  p. 
163;  Otia,  p.  117.— hch.  <'<nn/>fn«  CJPB.,  J/\ 

Carjientcr  writes:  Entire  surface  punctate;  central  areas  having 
the  lines  of   points  either  parallel  or  bending  toward   the  acute 
juguni ;  lateral  areas  having  small  radiating  \vrinkl<-s,  at  fii-t  :i  \<>  \ 
in  number,  then  splitting  into  6  to  8.     End  valvo  havin-j-  in  deli- 
cate, hardly  apparent  radiating  wrinkles.     Mucro  slightly  in   front 
of   the   middle,  slightly  elevated.     Interior:    posterior  valve  with 
13,  central   valve  1,   anterior  valve   14  slits;   teeth   acute;  • 
moderate,   acute;    sinus   wide,    flat.      Girdle   having   large,   solid 
imbricating  scales,  sometimes  very  slightly  striated.     Length  1  7   , 
breadth  10  mill.;  divergence  120°.     Philippines,  Mus.  Cumin_ 
11.     Dr.   Gould   strangely    placed    this    species    in    Leptochiton. 
although  the  scales  are  as  large,  solid  and  regular  as   in   Chiton. 
The  above  diagnosis  is  written  from  Mr.  Cuming's  beautiful  speci- 
mens, which   are  broad  and  externally  curiously  like  the  vein 
Chiton    (var.)  patulus.     In  the  typical  specimens,  the  striulation  of 
the  scales  can   seldom  be  seen,  having  apparently  lived  in  ex; 
situations.     The   variation    in    color   is   extraordinary,    being   (a) 
densely  clouded    with  olive;  (6)  light  ditto  mottled  with  dark  and 
lilac;    (f)  four  central  valves  chestnut,  the  rest  olivaceous;    (d) 
brown   with  olive,   with  broad   white  streak   down  the  centre ;  (e) 
light  reddish-chestnut  mottled  ;  (/)  ditto,  shading  into  oli 
(0r)  sixth,  seventh  and  part  of  eighth  valve  dark   olive-brown. 
rest  light  ashy;    (//)  the  whole  light  ash.     The  sutures  are  alwaya 
regularly  spotted,  as  in  T.  jtseudodentiens.     In  the  typical  specimen 
examined  there  were  only  eleven  slits  in  the  terminal  val\ 

I.  LEPIDUS  Gould.     Unfyured. 

Shell  small,  elliptical,  roof-shaped,  yellow-irreeii  >tn-akrd  with 
olive;  front  valve  semi-circular,  radially  striated;  posterior  valve 
crescentric,  beaked,  radially  grooved  behind  and  longitudinally  in 


118  I--  IINMI  mi.  P\.  . 

front;  lateral  arras  elevated,  sculptured  with  6  radiating  sulri  : 
central  areas  imbricatelj  sulrate.  (iirdle  narrow,  handed  with 
olivaceous,  covered  witli  minute  scales. 

Length  l:J.  breadth  !»  mill.     (G7d.) 

Interior:  terminal  valves  with  about  14,  central  valve.-  1  slit; 
teeth  very  acute,  but  a  little  serrated  at  the  edge.  Haves  large; 
sinus  narrow,  vaulted,  scarcely  laminate.  Girdle  irregularly 
imbricated  with  transverse,  solid,  neatly  smooth  scales.  (Cpr.) 

China  Sea,  Lot.  24*  N. 

Chiton  (Lepidopleura)  !f/n'<ln8  GLD.,  Proc.  Bost.  Soc.  >".  11.  vii,  p. 
H>4  ;  Otia,  p.  118. — Ischnochiton  /c/inlus  CPR.,  MS. 

The  girdle  scales  are  those  of  Lepidopletirus,  [—Lepidozona] 
except  that  the  imbrication  is  irregular.  The  species  is  remarkable 
for  the  narrow-,  arched  sinus;  and  for  the  slight  serration  of  the 
insertion  plates  which  are  yet  normally  sharp  and  protected  with 
broad  eaves.  I  have  not  been  able  to  re-examine  the  type  since  I 
matured  a  plan  of  arrangement  for  the  sections  of  the  genus.  (Q?r.) 

I.  PBTALOIDES  Gould.     PI.  23,  figs.  92,  93. 

Shell  small,  delicate,  elliptical,  roundly  arched,  very  slightly  car- 
inated,  the  valves  not  beaked,  of  a  pale  lemon-yellow  ground  color, 
reticulated  along  the  centre,  with  delicate,  angulated,  pale-violet 
line-:  these  areas  are  also  rugosely  lineate-punctate  longitu- 
dinally, especially  toward  the  margin  ;  lateral  areas  very  prominent, 
riiiro-rly  granulate,  and  with  about  four,  fine  radiating  stria? ;  pos- 
terior valve  acutely  umbonated  and  crossed  by  an  acute,  tran- 
rib.  Margin  cream-colored,  very  finely  granulate-imbi ; 

(Old.) 

Interior :  posterior  valve  having  9,  central  1,  ant.  v.  9  slits ;  teeth 
acute;  eaves  acute,  hardly  spongy ;  sinus  very  widt •.  short,  smooth. 
Girdle  imbricated  \\ith  flat,  scarcely  striated  scales.  (Cj>r.) 

Length  12i,  breadth  10  mill. 

Kan 1 1 1  <in>l   OaJnt^  SainhrirJt  /.«. 

C.  /»t« /•"''/'>•  <1  i.i»..  I'r«'c.  liost.  Soc.  N.  11.  ii.  p.  144,  July.  lM'i; 
t  .  >.  Kxpl.  Kxped.,  Moll.  SI...  p.  ::•_'  :  Otia  Concho).,  p.  (i  ; 

C.   (Luciu)  pdu/n!if>:<  (  \\.\t.,   (  Mia    p.   L'  4 '_'.—  J.n/Ji  tfru.<  /xf.i/n!,/,  .<    1^1     . 

Amer.  Journ.  of  Conch,  vii,  ]».  194. — Itchnochiton  i»inln't<l,  .<  Cv\\. 
MS. 

The  scales  an-   rather   lar.L'r   for   the  >i/c  of  the  shell,   but    thin, 
sprciiin-n-  have  sometimes  an    af>prarancr  of  minntr  >triula- 


i»  ii  \<  »  111  i  1  1!> 

tion,  from    tin-   contraction    of  tin-    epidermal    film.      I  >r.   Gould 

mi-"d  that  tliU  ipecitt  «mirht   t<>  lie    :i     Lucia,    i 

the    Pacific    Is.;   hut    it    is    a   normal    l-chnochiton    in   all   respects 

except  the  non  >triation  of  I  he  scales.      <  ( ///•.) 

I.  m-<  i   i.i-i  i  >  (  'arpeiiter,  n.  sp. 

Shell  small,  oval  ;  juu'iim  acute;  miicro  me.lian,  rather  elevated; 
:i>hy,  maculated  with  olivaceous.  Entire  surface  minutely  gnmu- 
lose  ;  central  areas  having  about  10  distant,  acute,  subparallel  lira-, 
sometimes  siih^ranose,  the  interstices  wrinkle-decussated.  Lateral 
areas  scarcely  raised,  ha  vim:  distant,  small,  much  raised  Drains,  Mih- 
radiately  arranged  in  --4  scries,  the  end  valves  having  16-20  such 
series.  Interior:  posterior  valve  having  7,  central  valves  1,  ante- 
rior 10  slits;  teeth  rather  obtuse,  roughened  but  scarcely  pectinated 
at  the  margin.  Eaves  small ;  sinus  small,  deep,  smoothly  laminate. 
Girdle  rather  regularly  imbricated  with  decidedly  transverse,  con- 
spicuously striated  scales.  Length  11,  breadth  6  mill. ;  divergence 
120°.  (<>/•.) 

/  Hong  Kong  (Stimpson,  N.  P.  E.  E.). 

"  Chiton  f  pulcherrimus  Sby."  GOULD,  MS.  +  C.  (Leptochiton) 
craticulatus  GLD.,  Otia,  p.  117,  pars.  (Cpr.). 

The  shells  forming  the  five  species,  pulcherrimus,  craticulatus  fcul- 
tratus,  bisculptus  and  asperior  were  included  by  Dr.  Gould  under 
the  first  two  names.  They  need  a  careful  examination  of  the 
details  of  sculpture,  as  well  as  of  the  mantle  scales,  in  order  to  sep- 
arate them.  Of  these  pulcherrimus  and  bisculptus  have  the  striated 
scales  of  Ischnochiton ;  craticulatus  and  cultratus,  the  strong,  smooth 
scales  which  belong  to  Lepidopleurus ;  and  asperior  is  intermediate 
between  Trachydermon  and  Cha3topleura.  The  decided; rugosity  of 
the  insertion  plates  and  short  eaves  of  this  species  form  a  transition 
toward  Chiton.  The  whole  group  appears  to  have  a  slight  lamina 
at  the  sinus,  marked  off  by  a  slit  from  the  sutural  wing.  (Qw.) 

7.    Group  of  I.  interstinctus. 

Small,  finely  granulated  shells,  the  lateral  areas  radially  ribbed. 
Scales  striated.  Species  of  the  west  coast  of  North  America. 

I.  IM  KKSI  IN.  n  s  Gould.     PI.  11,  figs.  40,  41  ;  pi.  21,  fig. 

Shell   OVal-oblong,    rather    elevated,    the    dorsal    rid;:*1     ohti: 
keeled,  side  slopes  nearly  straight.     Surface  apparently  smooth,  but 


1-"  I-'  !i.\<M  mi-ox. 

under  a  lens  it  is  seen  to  be  very  minutely  punctulate,  the  indistinct 
lateral  areas  hein.i:  ohsoK-tely  radiately  lirate  also.  Dark  reddi.-h, 
mottled  with  liirlit  on  the  dorsal  ridge. 

The  lat.-ral  arms  an-  >carcely  perceptibly  raised  and  besides  Ix-in- 
microseopieally  punctulate  like  the  rest  of  the  surface  thev  have  low 
radiating  ribs.  al)oiit  6*  or  7  in  number.  Central  areas  evenly 
punetulate:  end  valves  punetulate  and  radiately  multilirate. 
I'ml.o  ,,f  posterior  valve  in  front  of  the  middle,  rather  elevat.  d. 
Inside:  posterior  valve  with  ll\  anterior  valve  10,  median  valves 
1  slit  ;  teeth  acute,  eaves  moderate;  sinus  wide,  flat. 

(iirdle  densely  covered  with  small,  suboval,  delicately  striated* 
scales.  Length  \^>.  breadth  8  mill.;  divergence  110°. 

Xifk'i  ll'irhor  mnith  t<>  Monterey  and  the  Santa  Barbara  la.,  Cali- 
fornia. 

Chiton  interxtinrf,,.*  GLD.,  Proc.  Bost.  Soc.  Bost.  N.  H.  ii,  p.  ]  \:>  : 
M.,11.  T.  S.  Expl.  Exped.,  p.  315,  pi.  23,  f.  423 ;  Otia,  p.  230,  2  1_\ 
—Ischnnr/iit'tH  i ,itcr*liii<'tn*  Cn:.,  .1/N.  isj)!,  and  DALL,  Proc.  U.  S. 
Nat.  Mus.  1878,  p.  331. 

This  is  a  small  reddish  species,  characterized  by  the  fine  pun  ela- 
tion of  the  whole  surface  and  the  rather  coarse  but  low  radiating 
riblHs  of  the  lat.-ral  areas  and  end  valves.  The  sculpture  is  not 
well  shown  in  ( iould's  figures.  It  is  drawn  from  a  specimen  before 
me  in  fig.  39  of  pi.  LM,  representing  an  enlarged  half-valve. 

I.  M:\V(  -»MI;I  Carpenter,  n.  sp.      Unfigured. 

Sh.-II  small  wide,  tumid,  with  obtuse  rounded  ju<:um.  Mucro 
median,  rather  elevated.  Ashy  or  olivaceous,  ele-antly  clouded; 
central  an  ;i~  and  entire  surface  -raniilated,  the  granules  being 
<|uincuncially  arranged,  close  and  regular;  lateral  areas  scarcely 
defined, having abou!  4  lines  of  tubercles  which  are  hardly  elevat.  d. 
Posterior  valve  having  about  30,  anterior  valve  40  such  lino.  Inte- 
rior: posterior  valve  having  12,  median  1,  anterior  valve  11  slits;  teeth 
acute;  eaves  apparent ;  sinus  wide,  short,  scarcely  laminate,  (iirdle 
imbricated  with  large  striated  and  rather  regular  s-ale>.  Length 

83,  breadth  <i     mill.  :  diver-enee  100°.     (Cpr.) 

Sta.  Catalina  Is.  (Newc.). 
The  phm  ,,f  s  Milptuiv  somewbal  resemblee  that  of  /.  interetindus, 

though    coarser   and    diflJ-n-nt    in    d.-tail.      It    resembles    /.    rod 
'»  Illost    '  :•!    in    the    rounded    U-ak    ;md    larger  «cales 

(Cpr.) 


BVOOHFP  1  -J  I 


1.   i;  \  1.  1  \  N~  <  'arpenler,  n.  sp. 

Shell  r;itlirr  large,  \\ide,   elevatrd,   tin-    JULMIIII    ftCUte  ;   "li 
elegantly  radially  streaked  with    brown.        Interior   |»|,  <.\Jth 

two    In-own    rays.      Valves   delicate,    Hat,    product  d    in    the   -inn-    in 
front  :    mucro  in  front  <>f  the  middle,  .-eareely  elevated  ;  entiiv  >ur- 

face  quincuncially  granulated  ;  lateral  areas  scarcely  defined.  ;u,d 

with     the    end    valves     ohsoletely     sublirulate.      Interior:    pi,.-t- 
valve    having  JMO,   central    valves    1,   anterior   valve    ID    11    slits; 
teeth    acute;    eaves    small;   >imis    wide,    short,    scarcely    laminate. 
Girdle  regularly  covered  with  solid,  coarsely  striated,  moderate  sized 
scales.      Length  L'l,  breadth  If)  mill.;  divergence  110°.     ((  ', 

Monterey,  Cnlijoniin. 

The  internal  color-rays  are  seen  in  all  the  dead  valves;  the 
external  painting  resembles  Mo/xtl'm  vespertina.  The  sculpture  is 
on  the  plan  of/,  mterstinctus.  One  central  valve  of  one  specimen, 
on  one  side  only,  had  a  second  slit.  (Q>r.) 

8.     Group  of  I.  scabricostatus, 
I.  SCABRICOSTATUS  Carpenter.      Unfigured. 

Shell  small,  orange  colored,  elevated  ;  valves  gothic  arched,  jugum 
acute.  Entire  surface  very  closely  granulated  ;  lateral  areas  well 
defined,  with  3  subobsolete,  radiating  series  of  large  granule.-  : 
beaks  scarcely  apparent;  umbonal  margin  slightly  turned  inward, 
and  having  dark  spots  giving  a  false  appearance  of  teeth.  Central 
areas  having  separated  longitudinal  series  of  narrow,  subobsolete 
riblcts,  furnished  with  large  granules.  End  valves  having  similar 
radia'inir  granulous  riblets.  Umbo  of  posterior  valve  scarcely  cen- 
tral, little  projecting.  Interior:  sutural  plates  separated  by  a  large 
flat  sinus;  insertion  plates  subobtuse,  the  end  valves  having  1"-1_, 
central  valves  1  slit;  eaves  moderate,  subconspicuous.  (Jirdle 
wide,  closely  clothed  with  imbricating,  elongated,  transvei>«  1\ 
striated  scales.  Length  73,  breadth  41  mill.;  divergence  1 

(Cpr.} 

Catalina  Islan<I,  California,  in  lO-'Jo  fms. 

Le]iu1n/>f''ii,'n*  anibr'icttxtuhi*  Ci-i:.,    Hep.   Brit.   A.«so.   Adv.    8 
isi;:;,  p.  649;  IVoc.Cal.  Acad.  N.  S.  ii,  p.  -iVl.—Mm,,-  iW- 

costatu*  (  'i'ii.,  J/& 

The  sinus  has  a  thin,  smooth  lamina  separated  by  a  slit  on  each 
side  from  the  sutural  lamime.  It  is  a  small,  arched  oraii-. 

with  rows  of  prominent  granules  over  a  shagreened  surface,       ' 


l-i'llNn*  HI!'  >V 

N  i  ii  N-  <  'arpenter.       I'n  >/"  /'"'. 

11   small,   whitish,    tinned    \vitli    rOMafte;   valv»-  gi.thic-arched, 

mi    suharute;  entire    surface    minutely    irranulnse:  lateral 

-picii'Misly   il.  -lined,   having   strong   diagonal    and    sutural 

;  with  well  projecting  rounded  grains;  end  valves  hav- 

ini:  -uhohsolete  radiating  riblet>:  central  areas  having  about  s  di.— 

taiit,  raised   subgranulose  longitudinal    rihs   on    each    side,   the   rih< 

at  the  jugum  :   inter.-ticcs  latticed  with  suhradiating  rihlct-: 

umhnnes  conspicuous,  the  uinhonal  margin  deeply  toothed  by  a  wart- 

bearing  ril>.  the  teeth  8  to  10,  obsolete  toward   the  jugum  :  margin 

•  ly  intortrd.     Tnibo  of  posterior  valve  submedian.  slightly  j  >ro- 

•iiaririn  elegantly  pectinated.       Interior:  sinus  large,  Hat. 

:  rate  :  insertion-plates    acute,    broadly     uniiissate.  end 

••s  having  about  8  slits  ;  eaves  conspicuous.     Girdle  having  lar^- 

riated  scales. 
Length  61,  breadth  2-1  mill.  ;  divergence  90°.     (Cj^r.} 

,!   /xA//td,  20-30  fins. 


veredentiens  CPR.,  Rep.  Brit.  Asso.  Adv.  Sci. 
p.  'il!*:    I  'roc.  C'al.  Acad.  Sci.  iii,  p.  211. 

A  small  arched  species,  sculptured  like  /.  mertensii,  but  with  two 
8,  one  of  which  dentates  the  sutures.     The  girdle  scale- 
rat  her  large,  flattened  and  striated,  as  in  typical  I&knochiton. 

I.  BBRRATUB  (  'arjicnter.      Utifiyured. 

Shell  small,  ashy,  dotted  here  and  there  and  especially  at  the 
suture-  with  olive,  sometimes  spotted  with  red  ;  oval,  suhdepressed, 
the  sutures  indistinct;  entire  surface  mo.-t  minutely  granulated: 
lat'-ral  areas  strongly  defined,  provided  with  two  to  five  very  wide, 
obtuse  rihs,  no  interstices;  posterior  margins  elegantly  serrated. 
Central  areas  having  about  12  acute  parallel  ribs  on  each  ride; 
juLrum  obtuse,  scarcely  uinhonate:  with  subradiating  latticing  ribs. 
intei>tiees  impre.-sed.  Mucro  median,  obtuse.  End  valves  having 
about  20  obtuse  rihs,  like  the  lateral  areas.  Interior:  median 
valves  bifi>sate,  end  valves  with  about  !>  .-lit-.  Sutural  plates  i 
liirdlc  imbricated  with  large,  scarcely  >triated  .-cales. 

Length  8'.  breadth  ~>  mill.  ;  divergence  115°.      (<>r-) 

Caj"   >V.  /.  '  'fiwritin. 

Ischnochtion  terratut  CP&.I  Ann.iV  Mair.   Nat.    Hist.  (3)  xiii.  p. 


UN...  in;. 


I.    \i  1:1  OTINCT1  -  <  'arpeiiler,  n.  |p,       (  'nj 

Shell     resemblili  (f,     but      the     lateral      AfMI 

Scarcely     defined,     radial     and     Ion-it  udina! 
Kntire    surface    equally    granulated.       <  )ran-e    .-potted     \vitli 
Interior:    posterior  valve  having  11,  central  \alv<-  I,  anterior 
l.'J.-lits.      Len-th  «;..  breadth    \  mill.;   diver-ence  IIHI   .        r//r.) 

(  ''ilnlinn,    Ixluiitl,  (  'nl. 

Thl8  Species  is  known  from   Tr.jln.rti*    by    the    valvis    not    beini: 
beaked,    and    by    the    large    striated    scales    of    the    margin,    which 

nilile  tho>e  of  /.  scabricottatut.    (Cpr.) 
I.  DECIPIENS  Carpenter,  n.  sp.     t'njnjured. 

Shell  exactly  like  /.  /irrfinii/'ifii*,  hut  reddish,  rK-vatod,  the  JIILMIID 
acute  ;  scales  of  the  girdle  small,  striated. 

Length  15,  breadth  7-j  mill.;  divergence  105°.     (Cj>r.') 


This  very  pu//lin,ir  shell  differs  from  /.  *!nn(lriit<itii.«  in  it-  normal 
sinus  and  smaller  scale-  ;  I  cannot  help  suspecting  that  \\lnn  moi'e 
specimens  have  been  examined,  it  will  be  found  that  some  chara-ier-. 
generally  constant  between  species  and  even  groups,  are  occasionally 
variable  in  the  same  speeies. 


I.  CORIM  <;  \  it  s  Carpenter,  n.  sp.     Unfigured. 

Shell  similar  to  Ch.  sanguineus  in  form  and  varied  coloring  ; 
entire  surface  granulose;  central  areas  having  impres>ed  punctate 
wrinkles,  hardly  lirate  ;  lateral  areas  strongly  longitudinally  corru- 
gated. Interior:  posterior  valve  with  8-10,  anterior  valve  i 
central  valves  1  slit.  Sinus  wide,  flat.  Girdle  thin,  covered  with 
very  close,  very  small  striatulate  imbricating  scales. 

Length  13:],  breadth  7  mill.;  divergence  90°-100°. 

(  'otalina  Is.,  beach  to  40  fms.  (Cooper,  Cal.  State  Coll.  No>.  1  • 
1070,1074);   Todos  Santos  Bay  (Hemphill),  California. 

Differs  from  Stenoplax  samjuine.ii*  in  sculpture  as  well  as  in  the 
plan  of  mantle-ornamentation.  A  specimen  from  Todo-  Santo- 
Uay  (under  a  stone  between  tides)  collected  by  Henry  Hemphill,  is 
about  the  size  of  limactfornil*  from  Ma/atlan,  and  it  would  natur- 
ally be  so  called;  the  sculpture,  however.  i>  >«  -n-ibly  ditfi-rent,  both 
from  that  and  from  /'<///</.>•.  The  central  areas  are  minutely,  the 
juir;d  areas  very  minutely,  wrinkle-punctate,  wrinkle-  an-jular. 
irregular;  lateral  areas  moderately  dcfineil  and  el  and, 


llM  ISCIIN'M   HI  TON. 

ther    with    the  end    valves,    irregularly.   suhconccntrically   and 
>t  ron-jlv    c,.rni'_rat(  <1.      Mucm    median,    planate.      This    -pr<-i«-    i-   a 

ii/iij-  in  furin,  but  &  true  Itchnoehiton  in  its  imbricated  scales, 

which  arc.  bowever,  extremely  minute.  This  specimen  is  n-iruhirly 
arched.  much  less  elevated  than  the  type,  with  which,  however,  it 
agrees  well  in  particulars.  Length  '_M,  breadth  !»  mill.  (( 

I  am  unable  to  see  why  this  should  not  he  considered  a  .sVr///y/A/./-, 
imles-  it  !>e  on  account  of  the  smaller  girdle  scales;  but,  as  I  have 
not  seen  specimens,  I  deem  it  be.-t  to  leave  the  specie-  when-  (  'ar- 
penter  placed  it. 


I.  SUBCLATHRATUS  Pilsbry. 

Shell  suhrotund,  depressed  (at  an  angle  of  130°);  brown-olive; 
valve-  very  wide,  the  margins  lobed,  interstices  nearly  straight. 
Intermediate  valves  granulated  at  the  dorsal  ridge  and  more  or  [em 
all  over,  having  two  strongly  tuberculate  ribs,  one  diagonal,  the 
other  in  front  of  the  suture;  lateral  areas  small,  granulate;  central 
areas  having  four  longitudinal  bars  on  each  side,  the  bars  tuher- 
culate,  interstices  granulated.  Front  valve  having  about  eleven 
rounded,  suhtuberculate  radiating  ribs.  Girdle  very  wide,  having 
close  small  scales  ;  valve-margins  simple,  the  anterior  having  9  slits. 

Length  41,  breadth  3  alt.  -5  mill. 

,  under  stones. 


Lepidopleunu  rluthrnhi*  CPR.,  Mazat.  Cat.,  p.  1  05  (1857)  ,  /W»//o- 
r/tifhr'ifnx    (Vi:..    J/&  —  Not   Cli.  r/'itlirntu*   Ri:i:vi:,   Conch. 
Icon.,  pi.  xviii,  f.  113  (1847.) 

I  have  not  seen  this  species,  the  name  of  which  ha>  been  already 
used  by  Reeve.     Carpenter  write-  as  follow.-  : 

One  very  small  specimen  was  discovered  on  a  stone  to  which  a 
Crucibulum  had  been  attached,  beautifully  perfect  except  in  the  loss 
of  the  anterior  valve.  A  dead  anterior  valve  was  found  of  a  much 
larger  specimen  displaying  a  marginal  structure  like  that  of  /,. 
The  shell  is  remarkable  for  the  Mrong  bars  across  the 
central  area-,  and  the  stout  rows  of  tubercles  which  run,  tin- 

•-nally.  the  other  along  the  inteistitial  margin.       The  mantle  is 
v.-i-y  hr..ad  and  crowded  with  minute  Males.        '/"*.) 

I  have  no  opportunity  of  re-examining  the  type  of  this  minute 

shel.  bether  the  very  minut  n-e  sti-iated.      If  so,  it 

mii-l  clotdy  re-.Miihle   the    young   of   /.  .  The  jiaucity   of 


lr<  ll\<"  III  i 
genuine  Ttchnochitont  in  the  Gulf  fkuna  i-  n-mark:ih|'-. 

so  many  .-prcie.-  ;nv  found  I'urtlirr  north.      <  '///•.    l/> 
Section    Lrj,i'iln;nnn    Pil-hrv.    I  3 

LepuJopfetmi*  CARPENTER  (Table  of   lirgular  chiton- 
DM  i..  Proc,  r.  B,  Nat.  MII-.  1878,  p.  881,  type  /  Mdd. 

\  ,|   LtpidopleuriU  of  Ki--<>,  Hi-t.  Nat.    Kiir.    M«'-rid.   iv,    p. 
iX'Ji!,    nor    of    II.    iV.     A.ADAMS,   L  858,  HOT  of  CARPENTER,   Ma/at. 

Cat  i 

Valves  having  sharp  but  somewhat,  rugose  and  tliick  in>ertii.n 
teeth,  and  Mypically)  the  sinus  is  delicately  toothed  within.  (Jinllr 
covered  with  convex  scales,  usually  snioot liisli.  Type  /.  mer\> 

This  section  diflers  from  Ixcluxx-hitnn  not  only  in  havini:  the  gir- 
dle scales  convex  and  smooth  or  hut  slightly  striated,  hut  al>o  in 
the  toothed  sinus.  It  is,  however,  an  artificial  Lrrouj>,  the  species 
being  more  closely  related  to  a  number  of  diverse  /.W///W//Vo//x  than 
to  each  other.  Numerous  transitions  from  the  smooth  convex 
scales  to  tlat  striated  scales  occur,  the  variation  in  degree  of  stria- 
tion  being  considerable  in  some  species.  This  section  in  its  present 
limits  is  therefore  merely  a  temporary  expedient  for  convenience  in 
identifying  species.  It  should  rank  as  a  section  under  Minorhif<>n 
s.  s.,  rather  than  under  Isehnoradeia,  to  which  group  these  species 
have  no  especial  affinity.  The  status  of  the  name  Lepidopfatnu 
has  been  discussed  on  page  2  of  this  volume. 

I.  MI- UTKNSII  Middendorff.     PI.  26,  figs.  20-26. 

Shell  oval,  elevated,  with  angular  dorsal  ridge,  and  straight  -side- 
slopes.  Varying  in  color  from  orange-red  to  claret-red,  or  even 
dark  red-brown,  and  either  unicolored  or  speckled  and  blotched 
with  white. 

The  lateral  areas  are  elevated,  and  sculptured  wiih  radiating  rows 
of  elevated  pUStuleft  Standing  upon  a  smooth,  alm«»t  tlat  ground; 
the  pustules  of  the  SUtura!  row  often  irregular.  Central  area-  hav- 
ing acute,  narrow,  parallel  rai-ed  riblets,  the  intervals  bet  ween  them 
regularly  latticed  across,  except  at  the  dorsal  ridge,  where  the 
rihlcts  have  a  tendency  to  diverge,  and  the  CTOBS  hatchi  letfe 

End  valves  radially  pustulo.-e.  Mucro  central,  low,  tlat  and  incon- 
spicuous. 

Interior  white  or  blue-white,  the  median  valves  when  det-ached 
showing  broad  red-brown  ray.-  po.-teriorly.  the  end  valves  with 


[81   ll\.  H   II1TON. 

:,»•  same  color.  Sutnral  plates  low  ;  sinus  flat,  angular,  tinely 
toutheol.  Anterior  valve  having  10-11,  central  valves  1,  po>teri»r 
valve  10  slits;  teeth  rather  >hort  ami  obtuse,  and  u.Mially  di>tinctly 

belted  :  eaves  rather  wide. 

Girdle  tinn.  compact  lv  cover. d  with  regular,  solid,  oval,  >hinii>g 
scales,  which  are  usually  smooth,  but  frequently  are  superficially  or 

telj  striated    ii-.  22, 
Length  85,  breadth  L'l  mill. 
|.e,,LMh  :'>*.  breadth  2-°,  mill. 

Sitk't  iifinl/i  to  Mnnh-i'ci/,  ('of !j'"r/i in. 

Chiton  \  Mi  DP.,  Hull.  Acad.  Sc.  St.    IV-tcrsh.  vi.  p.  118, 

lsl«i. —  Chiton   (PhcenocJiiton,    Ilmnm-hiton,    Stenosemus)    merl 
Mi  1.1...  Mai.  Ro.-,  p.  :U,  125,  t.  14,  f.  1-3,   184?*— J*pfoeAiton 

mertentii  II.  £  A.  AD.,  (Jen.  Kec.  Moll,  i,  p. -47-">.  1>">4.  -J,rj,i'il>,- 
tM  )m-rten*ii  CPR.,  J/*S.,  and  DALL,  Proc.  U.  S.  Nat.  Mu-.  1  >7V. 
p.  8 

This  species  may  be  known  by  the  more  or  less  red  coloring,  the 
shining  convex  oval  scales  of  the  girdle,  which  are  usually  alnn»t 
smooth,  and  by  the  strongly  developed  sculpture.  Attention  has 
alr«-a'l v  been  directed  to  the  similarity  of  the  Ch&topleura  '/'""/"" 
«>f  Cpr.  i  p.  '•}}  i,  which  dillers  mainly  in  its  spar.-ely  hairy  girdle. 

-  iihrrn  examples  of  this  species  are  larger  and  more  frequently 
variegated  with  white  than  those  from  the  northern  part  of  its 
range;  and  the  girdle  scales  seem  to  be  more  distinctly  striated. 
They  seem  to  be  almost  or  entirely  smooth  in  mo>t  northern  speci- 
mens as  far  as  my  material  shows;  and  I  do  not  doubt,  that  Car- 
penter's figure  (pi.  26,  fig.  23)  was  drawn  from  a  specimen  collected 
north  of  San  Franoisoo.  In  almost  all  of  the  specimens  from  the 
smth  which  I  have  examined,  the  scales  show  a  delicate  striation 
\\hen  illuminated  from  the  side,  or  at  right  angles  to  the  direction 
of  the  stri;e.  This  is  shown  in  figure  2U,  drawn  by  the  author  from 
a  Monterey  specimen.  The  sculpture  of  the  valves  is  peculiar  ;  the 
!  area  ha-  diver_'inir  line,  with  smooth  intervals.  This  is 
always  most  pronounced  on  the  seconil  valve  (Hg.  lM  .  the  other 
valves  often  having  the  line  more  nearly  parallel,  and  the  intervals 
not  all  smooth.  This  is  shown  in  fi_r.  25,  repir-entiii-  a  fourth 
valve;  but  in  smm-  specimen-  the  divergence  is  even  le>s  pro- 
iiMiincrd  than  in  this.  The  pustules  upon  the  front  valve  occas- 
ionally become  soldered  \>  Uto  riblets,  but  those  of  the  tail 
val  mill  disti: 


l-<      H\M.      IN    | 

I.  .  OOPEBJ  ( larpenter,  n.  >p.     I'l.  •_'»;,  figg.  -j; 

shell  oval  an.l  elevated,  wiili  angular  dona!   i 
side-slopes,    Sculpture  like  Lmerientii.      ( 'oh.r  <,li\ae« ,,n.~,  or  dull 

earthy    In-own,    indistinctly   clouded    IM..IV   or   ten    \\iili    liirht    blue, 

especially  upon  the  side  areas.      The  lateral  areas  arc  iai-<d,  and 

hear  irregular  n«ws  «>f  rounded  pustules,  the  young  bavin-  four  : 
the  adull  (I  to  's.      A  >troiig   lens  reveals  a  line,  suhol»ob-te  irranula- 
tion  of  the  nearly  Hat    surface  between    the    pustules.       The  central 
areas  have  a  line  hut  distinct  and  even  radial  striation,   over   whieh 
run  acute  narrow  raised  threads  parallel    to   the  dur.-al  rid-c;   upon 
the    ridge  these  threads    are  seen    to  be  more    or    le.-s    divei-ifim:, 
specially   ii])on    the   second  valve.     The  end   valves    are   radially 
ridged,   the   ridges   bearing  elongated    pustules,   or   showing   - 
where  such  pustules  have  been.     Mucro  low,  flat. 

Interior  bluish,  the  valves  marked  under  their  innbnnes  with  dark 
olive.  Head  valve  having  11,  central  valves  1,  tail  valve  11  >lits  ; 
teeth  roughened  but  rather  sharp;  eaves  wide,  dark,  minutely 
punctulate,  but  solid,  not  spongy. 

( iirdle  compactly  covered  with  small  imbricating,  deeply  striated 
scales  (fig.  28).  Length  40,  breadth  24  mill. 

Xmt.tti  ('rn:  and  Bolinas,  California. 

This  species  closely  resembles  7.  mertei>*ii  in  shape  and  sculpture, 
but  it  differs  entirely  in  the  smaller,  distinctly  striated  or  grooved 
scales,  in  the  sombre  coloring  both  outside  and  within,  in  the  closer 
pectination  of  the  inter-liral  spaces  of  the  central  areas,  and  in  the 
more  developed  microscopic  granulation  of  the  lateral  areas.  It 
cannot  be  claimed  that  all  or  any  one  of  these  characters  is  invari- 
able, but  the  balance  of  them  taken  together,  seem  to  indicate  that 
differentiation  has  proceeded  to  a  stage  we  may  call  specific.  The 
following  species  is  allied  to  this  in  coloring,  but  differs  sufficiently 
in  sculpture,  a<  well  as  in  the  girdle-seal'-. 

The  details  of  sculpture  and   the  scales  of  all  three  >p 
drawn  to  the  same  scale.     The  third  valve  of/,  cooperi  is  >h..\vn  in 
tb-s.  I'D, :]().     It  must  be  remembered  that  the  valves  behind  this,  and 
usually  even  the  third,  have  less  markedly  divergent  -culpture  than 
the  typical  form  here  shown. 

The  specimens   herein    described   and   figured    are   from    Bolinas, 
north  of  San  IVanci-co,  and  since  no  diagnosis   has  been    published 
hitherto,  thc.-c  will  be  considered  the  typical  specimen-.     Carpel 
specimens  were1  from  Sta.  Crux. 


1-JS  [8GHNOGHITOK, 

I    8INUDENTATU8  ( 'arpcnter,  n.  sp.      Unfiyured. 

Shell  oval,  much  elevated,  reddish  :  juLTum  acute-;   nuicro  median, 
Iv    elevated:     entire    surface    minutely    irranulose.       Central 
-  lia\  mi:  about    12  Bubparallel  bare,  Which    pectinate    the    i'n.nt 
marLriu.  their  iutn  u--ated  :    lateral  areas  havini:  '5-4  irran- 

OSC  radiatini:  lira-,  the  anterior  valve  With  26,  posterior  valve  24 
such  Lim.  Interior:  anterior  valve  with  10,  central  1 ,  posterior 
valve  l)  slits;  teeth  acute;  eaves  conspicuous.  stibspongy,  crenulated 
by  the  sculpture ;  sinus  wide,  short,  laminate  with  ahout  «;  teeth. 
Girdle  having  moderate  si/ed,  wide,  conspicuously  striated,  rather 
iarly  imhrioatiDg  scales.  Length  15,  width  !••  mill.  ;  diver- 
gence 100°.  (fyr.) 

Monterey,  Cti/ii'u-uin. 

This  shell  has  the  color  of /.  mertensii,  nciirl/   the  sculpture   <•!' 
/.  f.cctumi.itn*   and  the  normal  scales  of  this  «rroup.      Like  /.  /•"/"- 
.  it  htis  the  denticulate  sinus  of  Chiton.     (Cpr.) 

I.  CLATHRATUS  Reeve.     PI.  26,  figs.  31-'U. 

Shell  oval  or  oldong,  elevated,   the   l>ack    carinated  :    >ide  slopes 
i\\\  :  lateral  areas  and  end  valves  radially  grauulate-lirate,  cen- 
tral areas  latticed.    Color  dingy  yellow,  clouded  with  black,  or  rarely 
unicolored  yellow  or  olivaceous. 

The  lateral  areas  are  raised  and  sculptured  with  about  5  rudia- 
atin_r.  clos-ly  and  conspicuously  irranose  rihlets.  the  posterior  rib 
wide  or  hilid  :  stroiiirly  [icetinated  alon<_r  the  sutuial  (d^e.  Central 
area-  havini:  longitudinal  narrow  bars  parallel  to  the  doi>al  i 

d    l»y    liars  of  almost   e<|iial    prominence   vertical   to  them, 
prodiieini:  the  effect  of  a  grating.     Mucro  depn-s-ed. 

fnterior  whitish,  with  olive  or  leaden  ra\s  under  the  uinboiie-. 
Sinus  flat,  denticulate;  anterior  valve  having  11 -I'-',  central  valves 
I,  posterior  Valve  14-HJ  >lits;  teeth  rather  sharp,  but  not  thin 

id; 

Girdle  Compactly    covered    with    very    convex    scales,    which    aie 
ob-oletely  striated. 
,jtli  27,  br.-adth   17  mill. 

Length  84,  breadth  is  mill. 

and  Son  to  I.>  Pout,  / 


i-i  IIN«H  mi' 

1'lu'ton  rfittlu-'itu*  III  I  A  i  .  <  '..nrli.   Iron.,  I.   18,  f,   US,    A  pi 
— Le}>i<l<>l>/''iin<x  jn-clinntint  (  Yi:.,  lYor.  (':ilit';i.  Arad.    \ 
I'll,  ISIJ.");    not   /,.  jici'tiniifn*  (  Yi:.  in   lit  it.  AjfO,  Hep.    i 

/.  OOOp0Tt  CPB.),  ii«>r   f'/iilni,  /,<'<•/!, iatn.<  Sou  i  RBY,  altOai 
(7; //OH  (jmt.,  j>.  I'.l  ).—  Li'indnjtlcnriiA  i,,'ctiinilutu.<<   <  Yl:.    .!/>'.    and  of 
Ainrriran  collectors  and  writers. 

Carpenter's  diagnosis  in  Proc.  Cal.  Acad.  Sri.  -eems  to  have 
included  both  this  species  and  /.  roopo-l,  but  he  afterward  distin- 
guished tlirni  upon  receipt  of  better  material,  and  re-Darned  the  prev- 
ent form  " pectin  tilatnu."' 

This  species  seems  to  replace  /.  mertensii  south  of  Monterey.  It 
is  a  dingy,  lusterless  shell,  resembling  mertensii  in  the  shape  of  tli<- 
girdle  scales,  which  are,  however,  not  so  bright  and  clean  in  the 
dalhrtitns.  It  has  decided  riblets  on  the  lateral  areas,  and  the 
lattice-work  of  the  central  areas  is  strong  and  much  less  finely  cut 
than  in  cooperi  or  mertensii.  From  /.  cooperi,  the  different  scaling 
of  the  girdle,  as  well  as  the  sculpture  of  the  valves,  separate  thi- 
form. 

The  second  valve  has  divergent  sculpture  on  the  dorsal  ridge,  but 
upon  the  other  valves  the  riblets  are  parallel  or  nearly  so  there,  and 
the  interstices  are  latticed. 

I.  COREANICUS  A.dams  &  Reeve.     PI.  27,  fig.  50,  (enlarged.) 

Shell  ovate,  rather  elevated,  terminal  valves  and  lateral  areas  of 
the  rest  radiately  grooved,  interstices  convex,  peculiarly  grained, 
grains  prominent,  round,  solitary ;  posterior  terminal  valve  um- 
bonated,  extremity  radiate,  small,  short ;  central  areas  longitudinally 
very  finely  granosely  ridged,  interstices  between  the  ridges  hollowrd  ; 
lateral  areas  blackish-green,  grains  yellowish,  central  areas  yellow- 
ish blotched  and  variegated  with  black ;  ligament  finely  granosely 
coriaceous,  tessellated  dark  and  pale  green. 

The  sculpture  of  this  species  is  not  much  unlike  that  of  C.  lurtdus ; 
still  it  is  distinct,  and  accompanied  with  a  very  characteristic 
of  painting.  The  central  areas  of  the  shell  are  of  a  yellowish 
ground,  blotched  and  variegated  with  black.  The  terminal  and 
lateral  areas  are  very  dark  green,  with  the  prominent  granules  con- 
spicuously tinged  here  and  there  with  yellow.  The  ligament  is 
strikingly  tessellated  with  dark  and  pale  sea-green.  (/. 

Korean  Archijtehtgo,  under  stones  (Belr: 
9 


130  I8CHN<><  IUTON. 


coreanicus  Ri:i:\  i.  I'.  X.  S.  1847,  p.  24;  Conch.  Icon.,  t. 
26,  f.  128.—  AI.AM-  iV  Kvi  :..  Voy,  'Samarang'  Zool.,  Moll.,  t.  15,  f. 
9.  —  S<  HIM  N<  K.  llek  u.  I-'oi-M-l).  ini  Amur-Lande,  ii,  p.  281,  f.  1-0. 
—  Lophyrus  c<>  DKK.,  Ind.  Moll.  Mar.  Jap.,  p.  1  ~>7. 

Carpenter  (MS.)  compares  this  to  /.  pcctinulatus  and  7.  co«y 
Schrenck  reports  it  from  the  Bay  of  Hakodadi,  on  the-  authority  of 
Lindholm. 
I.  JMI.CHKKRIMUS  Sowerby.     PI.  27,  figs.  47,  48. 

Shell  oval,  elevated;  jugum  acute;  mucro  conspicuous,  elevated, 
median.  tlie  slope  behind  it  concave.  Color  red,  variously  clouded 
or  streaked  with  ashy.  Jugal  area  hardly  defined,  smooth  at  the 
prominent  beaks  ;  central  areas  having  16  to  18  acute,  subparallel 
lir;«'  on  each  side,  meeting  over  the  jugum  but  otherwise  nearly 
parallel  ;  interstices  crenulated  ;  entire  surface  granulated.  The 
interstices  are  decussated  by  the  buttresses,  as  it  were,  of  the  cren- 
ulated sides.  Lateral  areas  with  3  principal  rows  of  close  knobs, 
inrreasing  to  5  rows  by  intercalation.  End  valves  having  16  to  20 
such  rows,  the  interstices  crenulated.  Sutures  with  sharp  rows  of 
granules  in  addition  to  the  contiguous  ribs.  Interior:  anterior 
valve  with  7,  central  1,  posterior  valve  10  slits;  teeth  obtuse, 
striated,  slightly  pectinated  ;  eaves  small  ;  sinus  deep,  flat,  dentic- 
ulate. Girdle  tessellated,  imbricated  with  large,  solid,  more  or  less 
striated  rounded  scales.  Divergence  97°-107.°  (Q>r.) 

Length  24,  breadth  13  mill. 

Island  of  Bo  hoi,  7  Vi  ///;>;// 

Chiton  j>nlc.herrimus  SOWB.,   P.    Z.   S.    1841,   p.   103.  —  Rr.i 
Conch.  Icon.,  t.  20,  f.  132. 

This  species,  says  Carpenter,  is  very  close  to  /.  merte»*ii.  The 
striation  of  the  scales  is  conspicuous  in  some  specimens,  on  others 
scarcely  seen,  yet  they  all  appear  conspecific.  The  species  is  exactly 
intermediate  between  the  two  genera,  Chiton  and  Ischnochiton,  the 
teeth  being  scarcely  pectinate  enough  for  Chiton,  and  yet  it  has  the 
balance  of  its  characters.  One  specimen  has  very  little  light, 
clouded  with  dark;  one  almost  entirely  light,  with  one  dark  streak 
on  both  sides  of  the  central  areas;  other  specimens  are  inter- 
mediate. (  Cpr.) 

I.  CRATICULATUS  Gould.     Unfigured. 

Mucro  central,  scarcely  elevated;  central  areas  having  18-22 
bars;  on  the  acute,  much  elevated  jugum  scarcely  obsolete; 


ISCIIN'M    ||  I  IMS. 

interstice.-  traDSVenely  wrinkled.      Lateral  areas  havini:  d< 
elevated  Lrraniferotis  rihlets,  1  in  ymni.Lr,  *  I"  H>  in  adult  individ 
anterior   valve    having   about    ~ti}    .-uch    riblet-.      Int.  i  '-rior 

valve  bavin-:  I  1 ,  central  valves  1,  anterior  valve  1 0  slits ;  teeth 
short,  not  very  acute,  outside  and  at  tin-  margins  in  (rout  rugulose, 
almost  pectinated  in  front.  Kav«>  -mall,  obi  <  |Q|  short, 

narrow,  slightly  denticulate.  ( lirdle  irregularly,  closely  imbricated 
•with  small,  smooth,  solid  scales. 

Length  1T>,  breadth  1 -~>  mill.;  divergence  93°.     (Cpr.) 
China  Nn/x,  orJii/xni  (Stimpson,  N.  P.  E.  E. ;  1  specimen  in  Mus. 
Smithsonian.) 

Chiton  (Le]ttochito)i)  craticiilatus  GOULD,  Proc.  Bost.  Soc.  K.  II. 
vii,  p.  101,  Dec.  1859;  Otia  Conch.,  p.  117. — Lepidopleurus  cratic- 

it tut u*  (1I'R.,  MS. 

Dr.  Gould  appears  from  his  diagnosis  to  have  had  several  species 
under  his  eye  when  he  wrote  the  description  of  this  species.  From  his 
calling  it  a  Leptockiton,  he  might  have  looked  at  the  minute,  chaffy 
scales  of  Trachydermon  asperior ;  when  he  wrote  of  long  striated 
scales,  he  was  probably  observing  Ischnochiton  bixculptus.  Again 
when  he  noted  the  great  variation  of  the  ridges  (from  4  to  8),  he 
probably  had  under  his  eye  both  /.  cultratus  and  the  species  above 
described.  Of  the  four,  the  balance  of  characters  inclines  me  to 
retain  the  name  for  the  shell  last  mentioned,  although  only  one  - 
imen  was  returned  of  it,  mixed  with  the  other  three.  Outside,  the 
species  is  recognized  by  the  solid  smooth  scales,  and  details  of 
sculpture;  inside  by  the  blunt,  somewhat  rugulose  teeth,  which  <  in 
part  of  the  anterior  valve)  are  almost  pectinate.  (Q;r.) 
I.  CULTRATUS  Carpenter,  n.  sp.  Unfigured. 

Shell  similar  to  "  L.  craticulatus " ;  mucro  central,  planate,  but 
central  areas  having  about  14  to  20  very  acute,  strongly  developed 
subparallel  lira?,  becoming  less  acute,  somewhat  obsolete,  on  the  dorsal 
ridge ;  sutures  elegantly  pectinated,  interstices  cancellated  with  small 
wrinkles;  lateral  areas  having  4  low,  gninifurous  liruhe,  and  a 
fifth  line  of  granules  at  the  sutures,  the  grains  sparse,  small,  but 
strongly  projecting.  Posterior  valve  having  about  18  similar  liruhe, 
anterior  valve  24.  Interior:  posterior  valve  having  i),  central 
valves  1,  anterior  valve  8  slits;  teeth  acute  :  eaves  projecting  :  sinu> 
small,  deep,  sensibly  laminated,  smooth.  (lirdlo  regularly  imbri- 
cated with  flat,  smooth  scales.  (Cpr.) 

.Length  27,  breadth  17  mill. 


132  racHHOOHirov. 

If'ilcud'idi.  Jit/Kin  >  Stimpson,  X.  P.  E.  E.  Smithsonian  Mu-.. 
1672.) 

Chiton  pult'herrimus  (pars)  GI.I>.,   J/\,  not  Sowr,. —  Leptorhiton 
•nlatus  G  i.i>.,  //<//>\  ( )iia,  p.  117.     (Cpr.) 

This  species  differs  from  /.  pulcherrimus  So werby  in  having  five 
rows  of  extremely  fine,  distant,  but  strongly  expressed  granules, 
instead  of  three  (rarely  four)  of  very  coarse  ones.  This  lias  the 
space  between  the  very  sharp,  knife-like  central  ridges  but  faintly 
cancellated  with  rugose  lines;  while  in  pulcherrimus  the  cancella- 
tion is  so  strong  as  to  make  the  ridges  appear  granular.  But  the 
principal  distinction  is  that  pulcherrimus  has  strong  striie  on  the 
mantle-scales,  while  those  of  cultratus  are  smooth  and  larger  in 
proportion.  It  has  the  same  general  aspect  as  /.  craticul<ttu*  ;  but 
differs  in  having  the  central  ridges  further  apart  and  sharper ;  the 
side  rows  of  points  scarcely  half  as  numerous,  and  the  scales  much 
larger  and  more  regular.  (  Cpr.,  MS.) 

I.  MUSCARIUS  Reeve.    PL  24,  figs.  9,  10. 

Shell  oval,  jugum  rather  sharp,  mucro  at  the  anterior  third, 
rather  raised,  the  slope  behind  it  very  concave.  Color  a  peculiar 
ash,  with  irregular  brown  spots  over  the  central  areas,  and  brown 
crescentic  lines  over  the  lateral  areas ;  and  valves  with  spots  of 
dark  shaded  with  light.  The  central  areas  have  a  conspicuous 
(juincuncial  granulation.  Lateral  areas  somewhat  raised,  with  about 
7  very  indistinct  small  riblets,  also  quincuncially  granulated,  and 
having  an  appearance  of  being  concentrically  sculptured,  caused  by 
the  color-markings.  Interior:  posterior  valve  having  12,  central  1. 
anterior  valve  12  slits;  teeth  very  sharp;  eaves  moderate,  not 
spongy.  Girdle  covered  with  imbricated,  smooth,  moderately  large, 
stout  oval  scales. 

Length  18*,  breadth  11,  divergence  119°.      (Cpr.  from  type  in 

r,  M.) 

Maxatlan. 

Chiton  muscarius  REEVE,  Conch.  Icon.,  t.  24,  f.  164. — Lepido- 
pleurus  muscarius  CPR.,  MS.,  p.  120. —  Lep'ulnp  tennis  f  mm-m 
CPR.,  Ma/at,  fatal.,  p.  196. — Ischnochitou  maeondrta  CPB.,  .!/>'.. 
p.  88. 

Carpenter  seems  to  have  decided  that  the  /,.  mnrandrei  of  his 
Ma/atlan  Catalogue  was  identical  with  Hoove's  C.  w/.-'m /•/'//.•*, 
although  he  remarks  that  he  would  not  have  known  it  from  the 


E8OHKOCHIT< 


and  description  u'ivrii  l»y   Reeve. 
I.  PUBIO  Sowerhy. 

Shell  oval,  smooth  ;  olivaceous,  ornamented  with  nimu-roiiggreen 
dots;  front  and  .-ide  margins  of  the  valves  rugulose.  Marginal 
ligament  scaly.  Length  12*,  breadth  7'  mill.  (Sowb.)  , 

Valparaiso,  on  Amphidrsma  Bolldum,  30-50  fin*.  ;  sand  bottom. 
Chiton  /mtio  S<>\\  KKI;Y,  I*.  /.  S.  1832,  p.  105. 

I.  DALMI  Haddon.     PL  25,  fig.  1-10. 

Shell  evenly  covered  with  closely  set  minute  low  tubercles,  wliieh 
give  it  a  granular  appearance;  with  straight-sides  meeting  at  an  an^le 
of  110°.  Anterior  valve  closely  granular,  with  twenty-six  short  radial 
rows  of  tubercles,  each  row  consisting  of  four  or  five  tubercles,  which 
diminish  in  size  from  the  periphery  towards  the  apex  ;  the  posterior 
row  is  the  broadest,  and  is  partially  bifid. 

Intermediate  valves.  Central  area:  jugum  coarsely  granular; 
pleura  with  about  12  or  13  distinct  horizontal  ridges;  lateral  areas 
granular,  with  three  main  radiating  rows  of  tubercles,  the  anterior 
and  posterior  often  partially  double.  Posterior  valve  remarkably 
fiat,  coarsely  granular,  with  nineteen  rows  of  three  tubercles  each,  of 
which  the  outermost  is  the  largest  ;  umbo  scarcely,  if  at  all,  raised 
above  thje  surface;  anterior  border  coarsely  granular,  with  the 
granules  passing  into  oblique  ridges  on  the  pleura. 

Girdle  medium  breadth,  upper  surface  with  smooth  imbricating 
scales  in  oblique  rows,  about  seven  or  eight  in  a  row,  those  nearest 
the  shell  being  the  smallest.  Color  greyish  -white. 

Length  11,  breadth  6,  height  about  3  mill. 

Gills  extending  to  about  three-quarters  the  length  of  the  foot, 
diverging  posteriorly  and  hidden  by  a  slight  swelling  of  the  longitu- 
dinal band  on  the  under  surface  of  the  girdle  ;  about  twenty-one  in 
number,  largest  about  the  fifth  from  the  posterior  end,  and  gradually 
diminishing  in  size  anteriorly.  (Haddon.) 

Lat.  51°  27'  30"  S,  long.  74°  3'  W.,  400  fins,  blue  mud. 

Lepidopleunu  dallii  HADDOX,  Challenger  Polyplac.,  p.  I1',  t.  1,  f. 
(>,  t.  :),  f.  6a-6i. 

I  have  associated  this  species  with  the  name  of  my  friend  Mr.  \V. 

II.  Dall,    of  the  Smithsonian   Institution,    Washington,   (      -     A 
(Haddon.) 


134  I-<   IIN«i  HITON. 

I.  MCI  i.osrs  Carpenter,  n.  sp.      Unfigured. 

'•11  oval,  little  elevated,  the  jugum  acute;  mucro  slightly 
elevated  ;  brown-olive,  elegantly  dotted  and  clouded  with  darker, 
and  sometimes  maculated  with  ashy  or  roseate.  Central  areas  gran- 
ulated in  a  somewhat  quincuncial  manner,  rather  regular  lines 
radiating  from  the  jugum.  Lateral  areas  scarcely  elevated,  having 
3  to  5  scarcely  projecting  radiating  wrinkles;  end  valves  having  30 
to  40  subobsolete  radiating  wrinkles,  and  granulated  like  the  central 
areas.  Interior:  posterior  valve  having  11,  central  valves  1,  ante- 
rior valve  11  slits;  teeth  acute;  eaves  large;  sinus  moderate,  flat, 
smooth.  Girdle  variegated,  regularly  covered  with  solid,  large,  sub- 
rotund  smooth  scales. 

Length  15,  breadth  10  mill. ;  divergence  110°.     (Qor.) 

St.  Vincent,  Cape  Verde  Is* 

Curiously  like  /.  comptus  in  color  and  sculpture,  but  that  species 
has  the  scales  extremely  finely  striated,  the  side  areas  a  little  more 
decided,  the  granulation  less  regular,  the  painting  more  sombre  and 
the  sutures  tessellated.  These  minute  differences,  joined  with  the  wide 
separation  in  locality,  probably  denote  a  different  origin.  (Cpr.) 

The  type  is  no.  88  of  the  Cumingian  collection. 

I.  OHTUSUS  Carpenter,  n.  sp.     Unfigured. 

Shell  small,  strongly  elevated,  oval,  the  jugum  little  acute;  mucro 
median,  conspicuous.  Reddish-brown,  variously  maculated  with 
paler.  Central  areas  having  about  10  subparallel  deep  sulci  on  each 
side,  obsolete  upon  the  jugum ;  lateral  areas  with  3  to  4  radiating 
wrinkles,  sometimes  divaricating,  the  end  valves  having  20  to  40, 
here  and  there  interrupted  by  wrinkles  of  growth.  Interior:  pos- 
terior valve  having  8,  central  valves  1,  anterior  valve  9  slits;  slits 
small,  teeth  very  short  and  obtuse,  sometimes  rugulose  or  almost 
pectinated  ;  calloused  inside ;  eaves  small ;  sinus  moderate,  exrurvnl, 
smooth.  Girdle  furnished  with  very  close,  small,  very  solid,  rounded, 
smooth  scales. 

Length  12$,  width  7'  mill.;  divergence  85°.     (Cpr.) 

Portugal  (Mus.  Cum.,  no.  105.) 

A  remarkable  shell,  presenting  some  general  resemblance  to 
mertensii  in  the  appearance  <>f  the  valves.  The  girdle  scales  are  as 
small  as  in  Trachydermon,  hut  very  solid.  The  specimen  is  much 
worn  outside,  which  may  account  for  the  bluntness  and  callosity  .if 
the  teeth,  (f/ 


[ft  HHO  mi 

I.  i  i  M  i  S)\\rrl»y.      11.  27,  l'iLr.    I  t. 

Shell  oval,  cariualed,  smooth  :    hack  elevated  ;    lateral  area-  i, 
spicnoiis.      (  'oh»r  lawny  hrown,  ornamented  with  rounded  hlue  Spots. 
Mar-in  minutely  scaly.      Length  1  .">,  hrradth  !>  mill.     (Sowb.) 

"Newcastle,  AvttraUa? 

C.  lentiginosus  Sown.,  The  Magazine  of  Natural  History,  con- 
ducted by  Ed  w.  Charlesworth,  iv,  new  series,  p.  293,  .June.  1840; 
Conch.  Illustr.,  f.  120. 

Chiton  cyaneopundatus  KRAUSS,  Die  Siidafric.  Moll.,  p.  40. 

Kxcept  in  heing  somewhat  larger,  and  said  to  be  from  a  different 
locality,  this  seems  to  be  absolutely  the  same  as  /.  cyaneopnndatut 
Krauss.  It  is  likely  that  the  Australian  habitat  assigned  to  lenti- 
guiosus  is  a  mistake.  The  description  of  cyaneopunctatus  here 
follows : 

C.  cyaneopunctatus  Krauss.  (PL  27,  figs.  40-43).  Shell  si.iall, 
oblong-ovate,  thin,  semi-pellucid,  convex,  carinated,  shining,  a.-hy, 
orange  or  brown,  closely  painted  with  dots  and  lines  of  blue ;  very 
minutely  punctulate;  intermediate  valves  narrow,  subrectangular ; 
lateral  areas  slightly  distinct ;  end  valves  delicately  concentrically 
striolate.  Girdle  ashy  and  rufous  banded,  scaly,  the  scales  distinct, 
subrotund,  polished,  shining. 

Length  10*,  breadth  6  mill,     (jfifr.) 

Cape  of  Good  Hope. 

The  valves  appear  smooth  to  the  naked  eye,  but  under  the  lens 
delicate,  elevated  points  are  visible  upon  the  central  areas  ;  and  on 
the  slightly  raised  lateral  areas  and  the  end  valves,  there  are  very 
delicate  concentric  striaB.  The  head  valve  has  12,  the  posterior 
valve  13  slits.  The  median  valves  are  very  narrow  (5'2  mill,  wide, 
1-2  long),  with  one  slit  in  the  insertion-plates.  The  scales  of  the 
girdle  are  as  large  as  those  of  C.  capensis  Gray,  shining,  convex  and 
rounded.  The  color  is  very  various  :  gray,  blue-gray,  yellowish  and 
reddish-yellow  to  brown  shells  occurring,  but  all  show  under  a  lens 
sky-blue  dots,  which  frequently  coalesce  into  lines.  Tho  girdle  has 
darker  transverse  bands.  (Krauss.} 

I.  DORSUOSUS  Haddon.     PI.  25,  figs.  11-19. 

Shell  remarkably  compressed  laterally,  the  two  sides  meeting  at 
an  angle  of  75°.      Anterior  valve  concentrically  ruirose,  with  about 
26  radiating  low  irregular  ridges,  some  of  which  hifuivate.     <  Vntral 
areas,  with  jugum  and  anterior  border  striated,  the  pleura  will 
tinct  horizontal  ridges.     Lateral  areas  distinct,  concentrically  rugose, 


136  i-«  IIN<>< •HITON*. 

usually  with  three  main  radiating  low  ridges,  the  anterior  and  pos- 
r  of  which  are  often  bifid.  Posterior  valve  concentrically 
rugose,  with  fifteen  irregularly  arranged  low  radiating  ridges.  The 
anterior  ridge  is  broader  than  the  others,  and  may  be  slightly  bifid, 
umbo  rudimentary;  anterior  border  smooth,  with  slight  concentric 
lines  of  growth.  Lamina-  of  insertion  moderate  in  size. 

Girdle  narrow.  Upper  surface  with  ovoid,  slightly  overlapping, 
somewhat  granular  scales;  edge  with  minute  projecting  spicules; 
under  surface,  with  long,  narrow,  closely  applied  scales.  Color 
white. 

Length  21'5,  breadth  7'f>,  height  6  mill.     (Haddon.') 

Prince  Edward's  Island,  Lat.  46°  41'  S.,  long.  38°  10'  W.  310 
fros. 

Lepidopleurut  dorsuosus  HADDON,  Challenger  Polyplac.,  p.  1 
1 ,  f.  5 ;  t.  3,  f.  5o-5t.  1886. 

Gills  extending  to  more  than  half  the  length  of  the  foot,  twenty  in 
number,  the  middle  somewhat  larger  than  the  remainder.  The 
name  dorsuosus,  full  of  ridges,  is  applicable  to  this  species  on 
account  of  its  numerous  longitudinal  and  radiating  ridges,  and  at  the 
same  time  recalling  the  steep  ridge  of  the  shell  itself.  (Haddon.) 

I .  \hii\  IDENSIS  Reeve.     PL  24,  figs.  7,  8  (enlarged.) 

Shell  somewhat  shortly  ovate,  very  minutely  reticulated  through- 
out, under  the  lens;  terminal  valves  and  lateral  areas  of  the  rest 
finely  ridged,  ridges  waved,  central  areas  smooth,  lateral  areas  not 
raised ;  livid  olive  and  yellow,  flamed  with  brown  in  the  middle, 
posterior  edges  of  the  valves  articulated  with  brown  ;  ligament 
Lrnmately  coriaceous,  grains  very  large.  (7?ve.) 

I '<>rt  Adelaide  (Rve.)  ;  Port  Molle,  Queensland  (Coppinger),  Aus- 
tralia. 

Chiton  adelaidensis  REEVE,  Conch.  Icon.,  1. 19,  f.  123. —  C.  (Isch- 
'itonf)  adelaidensis  E.  A.  SMITH,    Zool.    II.   M.  S. 'Alert/  p. 
79,  1884. — Lepidopleurus  adelaidensis  CPR.,  MS. 

Smith  L'ives  the  followini:  notes  on  the  specimens  collected  at 
Port  Molle  by  Coppinger: 

The  entire  surface  of  this  species  is  minutely  i:ranosely  reticulated. 
the  front  valve,  the  lateral  areas  of  the  narrow  central  valves,  and 
the  hinder  area  of  thepo.-terior  are  in  addition  somewhat  irregularly 
radiately  sulcate.  The  prevailing  color  is  pale  greenish,  streaked 
and  dotted  with  ivd,  the  posterior  mar-in  of  the  valves  brinLT  paler 


BtHO  HI  i  < 


than  the  general  tone  of  tin  >hell,  ami  con-picuou-i;,  \\itli 

the  same  red  color.      The  -ruins  ..f  the  mantle  an-  .-m«n.tli.  arranged 
in  alternate  grrrnisli    and    reddish    patches,  and  individually  have  a 

<lark  spot  generally  on  the  outer  side,  which  is  only  seen  under  a  lens; 

those  near  tho  valves  are  considerably  smaller  than  tho-e  situated 
toward  the  edire  of  the  girdle.  Having  parted  the  valves  of  or 
the  specimens  I  find  the  front  one  has  the  innrL'in  of  iii.-.-rtion 
divided  into  seventeen  unequal,  Bquarely  Out,  slightly  crinkled,  -harp- 
edged  teeth,  of  which  the  two  outer  on  each  side  are  the  largest. 
The  sixteen  slits  between  the  teeth  are  very  small  and  shallow. 
The  second,  third,  fourth,  fifth,  and  sixth  valves  have  on  each  side 
a  single  very  small  narrow  central  notch,  from  which  a  groove  or 
depression  runs  to  the  apex  of  each  valve  ;  the  seventh  is  probably 
abnormal,  having  a  single  notch  on  the  right  side  and  two  on  the 
left,  and  the  terminal  valve  has  nineteen  similar  slits. 

/.  milleri  (Gray)  Reeve.  (PI.  24,  figs.  18,  19).  Shell  ovate, 
smooth  ;  central  areas  under  the  lens  most  minutely  reticulated  ; 
lateral  areas  very  finely  striated.  Olive  or  sometimes  white,  blotched 
and  dotted  with  black.  Ligament  coriaceous,  tessellated  with  black 
and  yellow.  (Rve.*) 

"  Eastern  Seas." 

Chiton  milleri  ("Gray,")  REEVE,  Conch.  Icon.,  t.  23,  f.  156a  ;  t. 
24,  f.  1566,  c. 

This  species  was  not  described  by  Gray,  although  Reeve  refers  to 
the  Spicilegia  Zoologia.  It  has  been  stated  by  d'Orbigny  to  be  a 
synonym  of  punrtnlatissimus.  Carpenter  seems  to  think  it  the  same 
as  adelaidensis.  The  types  should  be  re-examined  in  order  to  settle 
the  point. 

I.  SMARACil  *ixrs  Angas.      1*1.  00,  fig.  20. 

Shell  oblong-elliptic,  elevated,  most  minutely  punctured,  dull 
bluish-green,  delicately  freckled  with  olive,  the  hinder  edges  of  the 
valves  ornamented  with  very  small  white  spots  bordered  with  olive  : 
the  terminal  valves  and  lateral  areas  faintly  concentric-ally  striated, 
the  central  valves  carinated,  with  the  dorsal  areas  faintly  trans- 
versely striated,  the  lateral  areas  slightly  elevated:  the  ma- 
margin  pale  green  marbled  with  black,  and  covered  with  small 
smooth  imbricated  scale-.  Length  1-  mill.  (Angas.} 

Lilac,  variegated  with  bluish,  the  >ide  areas  di-tinct,  slightly 
raised,  more  variegated  and  darker  than  the  central  areas.  ,Ji: 


138  I8CHNOrmi< 

sharp  ;  nmer<>  not  much  raised,  situated  at  the  front  fourth,  posterior 
slope  a  little  concave.  Valves  square,  not  beaked  :  Lrlo~\  -.  \\ith  very- 
fine  quineuneial  granulation.  Inside  :  posterior  valves  having  10  or 
11,  central  valves  1,  anterior  valves  11  slits;  teeth  sharp,  thin,  and 
rather  Ion-  :  >inus  broad,  deep,  flat,  not  channelled  at  the  sides ; 
eaves  projecting,  granulated  in  quincunx  but  not  spongy.  Girdle 
with  rather  large,  stout,  smooth  roundish  scales.  (Cpr.,  from 
types).  Length  13 J,  breadth  8  mill.;  divergence  iL'n  . 

Port  Jackson,  New  South  Wale*t  Austral  in. 

Lophyru*  *innr<i<t<li>ms  AN<;AS,  P.  Z.  S.  1867,  p.  115,  t,  13,  f.  28; 
t.  '•..  p.  '2"2'2. — Lepidoplenrus  smaragdinus  CPR.,  MS. 

I.  SULCATUS  Quoy  &  Gaimard.     PI.  38,  figs.  24,  25,  26. 

Shell  oval-oblong,  quite  convex,  obtusely  triangular,  with  narrow 
girdle  ornamented  with  little,  rounded  scales,  each  of  which  is  green. 
ish  with  a  brown  dot.  The  valves  are  wide,  arcuate,  almost  without 
carina,  very  prettily  grooved  lengthwise  on  the  sides,  and  zigzag 
in  the  middle.  The  lateral  areas  are  triangular,  granulose,  and 
elevated.  The  anterior  valve  is  simply  granulated,  with  11  or  12 
teeth;  the  posterior  valve  is  larger  with  13  teeth,  and  above  it  is 
striated  in  front,  and  with  marginal  granulations.  The  sutural- 
plates  are  short  and  separated.  All  of  these  parts  are  of  a  hand- 
some clear  green  varied  with  white.  The  base  of  each  of  the  lateral 
triangles  is  white.  Each  valve  has  at  the  summit  a  green  spot 
surrounded  with  whitish,  or  sometimes  with  rose,  in  which  case  the 
interior  also  is  roseate.  Length  30,  width  18  mill. 

Port  of  Kiny  Geor</e,  S.  Austral  in. 

C.  sulcatus  Q.  &  G.  Voy.  Astrol.  iii,  p.  385,  t.  75.  f.  31-36.— (Not 
Chiton  (Jiadsia)  sulcatus  Wood.) 

The  generic  position  of  this  species  cannot  be  known  until  the 
characters  of  the  insertion-plates  are  more  exactly  described.  The 
above  description  is  from  Quoy,  who  remarks  that  the  species  has 
considerable  resemblance  to  C.  viridis  Q.  &  G.  (G  </»/o?//  Dh.), 
differing  in  the  sculpturing  of  the  valves,  especially  the  end  valves. 

I.  TESSELI.A  i  r-  nuoy  &  Gaimard.     PL  24,  figs.  13,  14,  15. 

A  small  oval  species,  nearly  flat,  having  a  rounded  carina.  <  .rav- 
ish all  over,  but  under  a  lens  showing  white  and  brown  elongated 
spots.  The  valves  are  very  finely  granulous,  the  lateral  areas 
sulcated  radially.  The  two  end  valves  have  smooth  teeth.  12  in 
the  head  valve,  and  more  on  the  last  valve.  The  girdle  is  si-aly. 


in  i..\    i:  \  i. -ii  1.1  \. 

yellowish  or  greenish,  and  regularly  .-potted  \\itii  i.n,\\n.     ; 

is  narrow,  yellowish  ;   tin-  «;ills  almo.-t  reach  the  head. 
Length   1*.  breadth   1'J,  alt.    1  mill. 

I'nrt   (  '•//•/'•;•/•/,  A'< 

Chiton  teasel  In  ht.<  ({.  &  (J.,  Y«»v.  <!<•  PAstrol.,   Xooi.  iii,   j,. 
atlas,  t.  75,  f.  48-47. 

The  description  is  troin  that  of  Quoy  and  Gaimard.     The  coloi 
is  probably  less  vivid  than  shown  in  their  phite.     The  artist  of  tin- 
'Astrolabe'  seems  to  have  had  an  irrepressible  fondness  for  green. 

I.  ARBUTUM  Reeve.     PI.  24,  figs.  16,  17. 

Shell  ovate,  terminal  valves  and  lateral  areas  of  the  rest  retieulatt-1  \ 
decussated  with  grained  striae  diverging  off  posteriorly  ;  central  areas 
very  closely  sculptured  with  blunt  squarish  granules;  green  or  red- 
dish, dotted  with  black;  ligament  squamately  coriaceous,  tessellated. 
(Jfoe.) 

1'ort  h**tn<: 

.  C.  arbutum  Rv.,  Conch.  Icon.,  t.  24,  f.  162. 

Carpenter  thinks  this  is  probably  a  color  variety  of/,  adelaidensia^ 
He  gives  the  following  notes  on  the  8  specimens  in  the  Cuming 
collection:  Shell  ovate,  tolerably  elevated,  rather  broad ;  ju<ru  m 
more  or  less  obtuse.  Reddish  orange,  olivaceous  or  light  ash,  more 
or  less  spotted  and  clouded,  but  always  with  a  very  fine  tessellation  of 
dark  and  light  along  the  sutures.  Mucro  in  front  of  the  middle, 
the  slope  behind  it  concave ;  intermediate  valves  oblong,  not  beaked  ; 
central  areas  coarsely  and  very  regularly  quincuncially  granulated 
with  large  grains ;  lateral  areas  very  slightly  raised,  with  about  ^ 
rows  of  larger  grains.  End  valves  with  similar  grains,  which  are 
radiating  but  scarcely  in  lines.  Interior:  anterior  valve  havin- 

II,  central  valves  1,  posterior  valve  16  slits:  teeth  quit 
typically  Ischnoid  ;  eaves  large,  not  spongy.     Girdle  tesst  Hand  with 
olive  and  light,  covered  with  imbricating  short  roundish  and  quite 
smooth  scales.     Length  12^,  breadth  8  mill. 

Section  Radsiella  Pilsbry,  1892. 

Radsiella  PILS.,  Manual  of  Conch.  (I)  xiv,  p.  ~A  .Inly  i»5,  1892). 
Type,  /.  tridentatm  Pils.— Jschnoradsia^Miri^i  i :i:  MS.  and  DAI  i  . 
Proc.  U.  S.  Nat.  Mus.  1878,  p.  331.  Not  M//o/-,/,/.</./  SHOT  n .\\.. 
185,3. 

Valves  and  girdle  entirely  similar  to  those  of  the  mu-ma! 


1  4<  I  ISCHNOCHITON-RADSIELL  A  . 

chiton*,  hut  insertion-plates  of  the  intermediate  valves  having  twoor 
several  slits. 

The  present  section  differs  from  Ischnoradaia  Shuttleworth  (Lep- 
idora<l*in  ( 'pr.j,  in  having  the  girdle  covered  with  flat,  striated  scales, 
whilst  in  the  latter  group  the  scales  are  transformed  into  smooth, 
solid,  pebble-like  bodies.  Radsiella  differs  from  the  Radsioid  section 
/v/f/xw  in  having  the  short  contour  and  anterior  mucro  of  the 
true  Ischnoehitons,  and  in  the  normal  foot  and  gills. 

Carpenter's  use  of  the  name  Ischnoradsia  Shutthv.  for  this  group 
is  clearly  indefensible,  as  Shuttleworth  mentions  none  of  the 
>  now  included  herein,  whilst  his  diagnosis  covers  all  Radsioid 
forms  of  Iscknochiton.  I  have  therefore  restricted  the  namelschno- 
r>i'l*ia  to  the  forms  grouping  around  Shuttleworth's  first  species, 
auttralis. 

I.  TKIDKNTATUS  Pilsbry,  n.  sp.     PL  18,  figs.  35,  36,  37,  38,  39. 

Shell  small,  oval,  moderately  arched,  slate-color  with  white  spots 
and  dots,  or  white  mottled  with  slate ;  the  girdle  tessellated  with 
alternate  dark  and  light,  the  interior  blue,  with  a  leaden  spot  under 
each  BUtural-plate,  and  short  dark  rays  from  the  apex. 

The  valves  are  evenly  arched.  The  posterior  valve  (fig.  39)  has 
a  central,  rather  depressed  umbo,  the  slope  behind  it  concave. 
Lateral  areas  raised  a  trifle,  but  scarcely  distinguishable;  central 
areas  evenly,  closely  and  finely  pitted  in  quincuncial  pattern ;  the 
lateral  areas  are  a  little  more  coarsely  sculptured  with  close  low 
diamond-shaped  granules ;  the  granulation  generally  less  regularly 
arranged  on  the  end  valves  than  on  the  lateral  areas. 

Interior  with  low,  arched  sutural-plates  and  wide,  flat,  angular 
sinus;  anterior  valve  with  13,  posterior  12,  central  valves  2  slits. 
Teeth  sharp,  smooth.  Eaves  very  narrow. 

Girdle  covered  with  imbricating  striated  scales  (fig.  36.) 

Length  15,  breadth  10  mill. 

l.aTnz,  Lower  California  (Lockington) ;  Gulf  of  California 
(Gab!..; 

/       •  M ,/•'/</, -l,t  d ispar  C  A  i :  i  •  i :  N  r  i :  K,  ^fS.  n  ot  Sow  i :  i :  i :  v . 
This   species   is  easily  separated  from  I.  dispar  Sowh.    by  the 
apparently  similar  sculpture  of  central  and  lateral  arras,  the  sculpt- 
ure in  iH*intr  being  obviously  diverse  on  these  areas.     I  suppose  this 
to   be  what   Carpenter   considered    ih'.tpar   merely    because   it  has 
valves  :  but  Carpenter  has  given  no  description  of  his  shells. 


l-<   IINoi  III  |..\     l;  \  |. -|  1. 1. 1, A.  1  II 

Tin-  l'"«t  i-  not    produced    forward    l>ni<';ith    tin-    h<  ad,    a-    i: 
Stenoradria,      The    irills   extend    from    tlic    front    end   of  tl 
within  somewhat  less  than  tin-  width  of  a  valv  from  tin-  t.iil  •  -, 

I.  vii:ii.ri.r>  Couthouy.      1M.  17 

Shell    small,   ohloiiLr,    rather  elevated  and  dc«-id»-dlv    «;irinated; 
creamy  yellow,  or  "of  a  very  pale  olive  or  drab  color."     Surface 
smooth  to  tlio  naked  eye,  but  under  a  lens  it  is  seen  to  be  every- 
where  covered    with    low   granules  quincuncially  arranged, 
lateral  areas  are  a  trifle  raised,  but  not  distinctly  so,  and  upon  them 
the  granulation  is  somewhat  effaced,  and  a  few  very  obsolete  radiat- 
ing sulci  are  generally  distinguishable,  as  well  as  several  rather 
strongly  indicated  growth-periods.     "Interior:  posterior  valve  hav- 
ing 13-14,  (rarely   17),  anterior  valve  14-16,  central  valve?- 
slits.     Teeth  acute,  distant;  eaves  acute,  projecting,  hardly  spot 
sinus  wide,   short,  flat.     Girdle  covered  with   rather   large,   wide 
scales,  deeply  and  distantly  striated."     Length  13,  breadth  7  mill. 

Orange  Harbor,  Terra  del  Fuego. 

Ch.  viriduhis  COUTH.  MS.,  GOULD,  Proc.  Bost.  Soc,  N.  H.  ii,  p. 
144,  1846;  Otia  Conch.,  p.  5 ;  U.  S.  Expl.  Exped.,  Moll.,  p.  318; 
atlas,  f.  413. — Ischnoradsia  viridulas  CPU.,  MS. — Lepidopleurus  viri- 
dulus  KOCHEBR.,  Miss.  Cape  Horn,  Polyplacophores,  p.  140. — 
'f  Minochiton  viriduhis  Gld.,  HADDON,  Challenger  Rep.,  p.  16,1886. 

A  small  form,  evenly  granulated,  and  having  indistinct  lateral 
areas.  I  have  taken  the  description  of  the  internal  parts  from 
Carpenter's  MS.,  as  I  have  not  examined  the  interior  of  the  single 
specimen  before  me,  which  is  one  of  the  original  lot. 

I.  TRIFIDUS  Carpenter.     PI.  18,  fig.  40. 

Shell  rather  large,  rather  elevated,  regularly  oval  ;  red-ehotnut. 
maculated  with  lighter  and  darker;  jugum  acute,  gothic.  Mucro 
median,  flat;  entire  surface  very  minutely  granulated  ;  central  areas 
having  about  8  strongly  punctate  lines  perpendicular  to  the  jugum  ; 
lateral  areas  strongly  defined,  having  2  to  4  obsolete  ribs,  sonutim.- 
punctate  in  the  interstices. 

Interior  whitish  flesh-colored,  with  two  reddish-purple  rays  diverg- 
ing from  the  flat  umbones  ;  posterior  valve  havin_r   !•'>,  anterior 
central  valves  2  slits;  teeth  acute,  sometimes  serrated  at  the  edge, 
sometimes  striated  outside,  sometimes  smooth.     Kaves  subspongy ; 
sinus  small,  laminate,  the  lamina  slit  at  the  sides  and  sometimes  in 


14'J  ISCIIN.X  mi'.N    IIAI.HI.I.I.A. 

the  middle.      <;irdlc  having  very  small,  solid,  >mooth  scales.      Gills 
almost  ambient.      (  <  'pr.) 

Lenirth  40,  breadth  i>ii  mill.:  divergence  135°. 

Sitka  to  Pug^t  Sound,  9-18  fms. 

Tr.H'hwI.nnn,,  tni',,ln.«  OR.,  Suppl.  Kep.  B.  A.  1863,  p.  l>4'.»  ; 
Proc.  Acad.  Nat.  Sci.  Phila.  1865,  p.  60. — Ischnoradsia  trifida  CPR., 
.!/>..  and  PXI.I.,  I'roc.  U.  S.  Nat.  Mus.  1878,  p.  881. 

I  have  not  seen  this  species.  The  figure  is  from  a  rude  sketch  in 
Carpenter's  MS.  Dr.  Dall  writes  of  it  as  follows: 

This  rare  and  fine  species  is  not  particularly  handsome,  being  of 
dull  and  livid  colors,  but  is  peculiarly  characterized  by  the  straight 
transverse  ribs  on  the  dorsal  areas  with  spongy  interspaces,  and  by 
the  pretty  regular  division  of  the  lateral  areas  into  three  well 
marked  radiating  costa?,  which  are  separated  in  the  insertion  plate 
by  two  fissures.  No  other  species  of  the  region  resembles  this  in 
srulptuiv.  Mu/x.le  with  a  pectinated  margin  in  front  produced  into 
rounded  lappets  at  the  corners.  Gill  rows  as  long  as  the  foot,  con- 
taining each  28-35  branchiae.  Veil  absent.  Mantle  edge  plain, 
narrow.  There  is  a  small  spherical  lump  on  each  side  of  the  girdle 
just  behind  the  posterior  ends  of  the  gill-rows,  which  are  turned  out 
toward  the  girdle  and  widely  separated  behind.  The  anus  is  large 
median,  and  crenate,  opening  on  the  upper  part  of  the  hinder  end  of 
the  foot.  No  ovarian  openings  could  be  detected,  and  the  species 
presents  some  peculiarities  which  call  for  further  research  with  more 
material.  (Dall.) 

1.  KKCJULARIS  Carpenter.     PL  18,  figs.  41-46. 

Shell  oblong,  elevated,  dorsally  carinated,  the  side  slopes  straight. 
Surface  appearing  almost  smooth  to  the  naked  eye.  Color  a  uni- 
form olive  or  slaty-blue,  the  girdle  having  more  or  less  of  a  blue  or 
purple  "  bloom." 

The  lateral  areas  are  very  little  raised,  and  are  sculptured  with 
numerous  delicate  radiating  threads,  occasionally  branching  toward 
the  lower  margin,  and  freely  branching  along  the  posterior  edge  of  the 
valve.  The  terminal  valves  have  similar  delicate  radii.  The  central 
areas  have  numerous  longitudinal,  somewhat  beaded  threads, 
separated  by  flat  intervals.  The  posterior  valve  is  elevated,  with 
anterior  uml»o. 

The  interior  is  light  blue.  Sutural  plates  low,  connected  across 
the  HMIIS  by  a  narrow  plate  which  is  silicate  above  and  cut  into 


in i"N  i: \ Den  1 1  \. 

;ihi>ut      10    trrth    liy    delirat"    .-lit-.       Anterinr    v:il\«-    : 
•  Tin  nil   '2   •".,   poMrrior    •_'•_'    -lit.-.     Terth    even    MIL!    -harp,    -li. 
-triatrd    or    grooved   outside.      Kav.-  solid,     (lirdle  uid«  ,  • 
eivd    with   solid,   regularly   and    closely    imlmeat  iiiLr  -triuted   Scales 
16),      Len-th  85,  lueadth,  1H  mill. 

Monterey,  ( 
c/iifnn   regulari*  CPB^  P.    /.  B,    1855,   p.   'i'.vi.--l.--'>.l,<.,,,(bia 

r  I- y  n/>  m'.*  CPB.,  J/N. 

This  species  is  of  a  very  regular  form,  and  a  uniform  dral>,  -dive 
or  blue  color.  It  is  not  closely  allied  to  any  other  West  Coast  form. 
Tlui  number  of  slits  in  the  posterior  valve  is  unusually  large. 

I.  TIGRINUS  Krauss.     PI.  19,  figs.  60-63. 

Shell  oblong,  convex,  roundly  arched,  buff-white,  unicolored,  or 
striped  lengthwise  with  reddish  ;  rarely  roseate. 

Valves  without  apices.  The  lateral  areas  do  not  extend  to  the 
middle  of  the  back;  they  are  raised,  and  cut  into  radiating  riblets 
by  8  or  10  narrow  impressed  grooves,  and  there  are  rather  con- 
spicuous concentric  wrinkles  or  waves  of  growth  on  the  lower  part 
of  the  areas.  The  end  valves  are  similarly  sculptured.  Central 
areas  closely  and  regularly  pitted  all  over.  Posterior  valve  rather 
large  and  depressed,  with  subcentral  urn  bo. 

Interior  white  and  light  brown.  Anterior  valve  having  17-18, 
central  valves  2-3,  posterior  valve  12-13  slits;  teeth  rather  thin, 
but  somewhat  bevelled  and  roughened  inside;  eaves  solid.  Sinus 
wide  and  flat,  the  sutural-plates  being  rounded.  Muscle-scars  dis- 
tinctly impressed. 

Girdle  rather  wide,  firm,  densely  clothed  with  somewhat  coir 
finely  striated  scales  (fig.  63).     Length  22-28  mill. 

Cape  of  Good  Hope. 

Chiton  tiyrinus  KRAU&S,  Die  Siidafric.  Moll.,  p.  38, 
?  Ischnoradsia  subcariosa  CPR.,  MS. 

This  species  is  readily  known  by  its  Radsioid  valvi-  and  tln> 
beautiful  web-like  sculpture  of  the  central  areas,  produced  by  the 
pattern  of  regularly  arranged  rhombic  pits.  It  is  like  no  other 
species,  although  the  young  of  /.  magdaleneiisis  bears  a  slight 
resemblance  in  the  sculpturing  of  the  central  areas. 

Although  technically  a  Radxiella  or  Stenor'  is  not  easy  to 

decide  which)  this  species  probably  was  developed  from  a  different 
stock  of  Ischnochitons.     Indeed,  the  multiplication  of  side-slits  may 


1  1  I  [SCHNOCHTTON-IBCHNORADeiA, 

,i'ccted  to  occur  in  any  branch  of  Chitons;  from  the  genus 
IschnochUon  alone,  we  have  at  least  tour  or  five  independent 
Kad-ioid  branches. 

The  typical  /.  tiyrinm*  of  Krauss  is  >triped  longitudinally.  The 
unstripnl  form,  of  which  several  specimens  are  before  me,  may  be 
called  var.  nnicolor. 

The  species  mentioned  by  Carpenter  as  /.  subcariosa  may  be  a 
form  of  /.  tiijruina.  The  type  is  a  single  specimen  of  unknown 
origin,  and  is  in  the  museum  of  McGill  College,  Montreal. 

Subgenus  VII.     ISCHNORADSIA  Shuttleworth,  1853. 

Ischnoradsia  SHUTTLW.,  Berner  Mittheil.  1853,  p.  65,  species  cited 
C.  australix  and  C.  magdalenensis.     Not  Ischnoradsia  CPR. — Lepido- 
radsia  CARPENTER,  MS.;  and  DALL,  Proc.  U.  8.  Nat.  Mus.  1 
p.  33 1 ,  type  C.  australis. 

Valves  having  sharp  but  rather  thick  insertion  plates,  those  of 
the  median  valves  with  two  or  several  slits.  Girdle  covered  with 
convex,  pebble-like,  smooth  scales.  Type  Chiton  australi*  Sowb. 

The  typical  forms  of  this  section  are  from  the  Australian  seas,  but 
several  species  have  also  been  found  in  Japanese  waters. 

Carpenter's  substitution  of  the  name  '  Lepidoradsia  '  in  place  of 
Ischnoradsia,  was  in  direct  violation  of  the  rules  of  nomenclature. 

Key  to  species. 

a.  Sinus  dentate  within,  albrerhti. 

ad.  Sinus  smooth. 

b.  Central  areas  longitudinally  ribbed,          australi*,lHt/ubrw. 
bb.  Central  areas  minutely  granulated. 

c.  Outside  green,  inside  green  and  pink  ;  scales  very  convex, 

novcehol/andke. 
cc.  No  green  or  pink  ;  scales  small,  convex,        lutkodadensis. 


I.  AUSTRALIS  Sowerby.     PL  18,  figs.  57,  58,  59. 

Shell  oval-oblong,  moderately  elevated,  the  dorsal  ridge  sub- 
angular,  side-slopes  nearly  straight.  Color  dark  olive-brown,  the 
apices  of  the  valves  pink  when  eroded. 

Lateral  areas  somewhat  raised  and  sculptured  with  close,  unevt  n 
riblets,  which  usually  bifurcate  or  branch  freely,  especially  toward 
the  posterior  maririn  of  the  area.  Crntrdl  ureas  closely  and  eienly 


rSCHNCX  HITOB    fSCHlfOB  LDtt  \. 


?/•////    y/'/irr    /nni/ifinlinu/    r/A/r/x,    ;>}>-<.  Ictc    »n    t! 
win  -iv  they  _irivc  place  to  a  d»-n.-r  microscopic  Lrran  illation. 
apices  of  the  valvc^  arc  pink  in  mature   >he!U.      Knd  valves  sculpt- 
ured with  clo>r  radiating  ril.lets,  those  of  the  posterior  valve  irreg- 
ularly ^ranose;  IIUHTO  rather  depres.-ed  ;  posterior  slopes  of  th- 
valve  depressed  and  concave. 

Interior  liirht  blue-green,  with   two  wide  pink  rays  in  each  v 
and  behind  them  two   olive-brown    rays.       Sntural    plates   nun 
whitish  or  yellowish;  sinus  wide,    flat,    not    in    the    least  toothed. 
Insertion  plates  having  16-21  slits  in  the  anterior,  2  or  3  in  the 
median,  and  17-21  in  the  posterior  valve;  teeth  rather  thick  and 
stumpy,  and  a,  little  rugose,  but  sharp  edged.     Eaves  wide  and  solid. 
Girdle  (fig.  57)  wide,  closely  covered  with   conspicuous,  convex, 
pebble-like  scales,  which  toward  the  outer  edge  are  subcatinated  in 
the  middle. 

Length  62,  breadth  35  mill. 

Port  Jackson,  Australia. 

Chiton  australis  SOWERBY,  Mag.  of  Nat.  Hist.  (Charlesworth's), 
June,  1840,  p.  290  ;  Conch.  Icon.,  f.46.  —  REEVE,  Conch.  Icon.,  t.  2, 
f.  lO.—Lophyrus  australis  ANGAS,  P.  Z.  S.  1867,  p.  221.—  Lepido- 
radsia  australis  CPR.,  MS.  and  DALL,  Proc.  U.  S.  Nat.  Mus.  1878, 
p.  279,  t.  2,  f.  19  (dentition)  ;  p.  333  (branchia>).—  HADDON, 
'  Challenger  '  Rep.,  Polyplac.,  p.  1  9.  —  Chiton  (Ischnoradsia)  australis 
SHUTTLW.,  Bern.  Mittheil.,  1853,  p.  66.  —  C.  evanidus  SOWERBY, 
Mag.  Nat.  Hist,  iv,  June,  1840,  p.  291  ;  Conch.  Illustr.,  f.  139.—  C. 
metallicus  RVE.,  Conch.  Icon.,  t.  17,  f.  104,  1847. 

This  species  is  distinguished  from  the  following  by  the  fine  longitu- 
dinal ribbing  of  the  central  areas.  The  synonymy  given  above  is 
unquestionable. 

Occasionally  one  or  more  of  the  teeth  is  cloven  into  a  number  of 
small  ones  ;  the  number  of  teeth  varies  considerable. 

Dall  found  the  gill  rows  to  extend  the  whole  length  of  the  foot, 
and  to  contain  forty-seven  branchiae  in  each.  Mantle-edge  plain, 
thin  ;  muzzle  plain,  semicircular,  without  a  veil. 

I.  NOV.EHOLLANDI.E  (Gray)  Reeve.     PI.  19,  figs.  67,  68,  69. 

Shell  oval-oblong,  elevated,  the  dorsal  ridge  an.Lrul:<  opes 

nearly  straight.     Color   green,    minutely  marbled   with    olive,  the 
lateral  areas  darker. 
10 


14''.  GBCHNO<  in  i'  H  iRADBIA, 

•••r;il  areas  somewhat  raised,  sculptured  with  low,  uneven,  some- 
what nod  ulous  radiating  riblets,  and  some  concentric  growth-wrinkles. 
•  ireas  smooth  o-<r/>f  /o?*  a  very  dense  and  reijnhtr  microscopic 
fjrnniilnti<ni.  Knd  valves  having  radiating  rihlets;  mucro  rather 
prominently  raised  ;  posterior  slope  concave.  Interior  blue-green, 
with  pink  and  olive  rays.  Sutural  plates  rounded;  sinus  smooth, 
not  toothed.  Anterior  valve  having  about  19,  central  valve- 
posterior  valve  1*  slits.  Teeth  thick  but  sharp  ;  eaves  wide,  solid. 

<  iirdle  covered  with  smooth,  solid,  pebble-like  scales,  which  toward 
the  outer  edge,  are  subcarinated.     Length  43,  breadth  23  mill. 

Adelaide,  S.  Australia. 


Horn  hollnidicc  (GRAY,  MSS.  in  Brit.  Mus.)  REEVE,  Conch. 
Icon.,  t.  21,  f.  142,  May,  1847. 

This  species  has  much  the  appearance  of  I.  australi*,  but  it  differs 
totally  in  the  sculpture  of  the  central  areas,  and  somewhat  in  that 
of  the  lateral  areas.  The  girdle  is  just  like  that  of  australia,  except 
that  the  pebbly  scales  are  smaller  in  a  specimen  of  the  same  size. 
Carpenter  erroneously  considered  this  species  a  synonym  of  Chiton 
''  U<i<l$ia)  goodalli. 

I.  LUGUBRIS  Gould.     Unfigured. 

Shell  small,  solid,  punctate,  elongate-ovate,  slightly  carinated, 
emerald-green.  Central  areas  sculptured  with  longitudinal  line, 
smooth  at  the  apices.  Lateral  areas  elevated,  having  branching 
nodulous  line.  Knd  valves  radiated  at  the  margins,  umbo  sub- 
central.  Girdle  wide,  covered  with  large  transverse  convex  scales. 
(.Old.} 

Interior  :  end  valves  having  19-24,  central  valves  2-4  deep  slits; 
teeth  acute,  sometimes  a  little  rugose  at  the  margins  ;  eaves  very 
short,  spongy  ;  sinus  broad,  flat,  smooth.  Girdle  imbricated  with 
very  solid  narrow,  nearly  smooth  scales.  (Cpr.) 

Length  25,  breadth  15  mill.     (Old.) 

Habitat  unknown, 

Chiton  (Lojthyrus^)  luyubris  GOULD,  Proc.  Bost.  Soe.  Nat.  Hist. 
vii,  p.  1  »'>-">,  Dec.,  1859;  Otia  Conch.,  p.  116.  —  Lepidoradiia  lugubri* 

GUI..  <  I'.:. 


The  girdle,  says  Carpenter,  is  very  like  that  of  7.  <insfr<ilit,  from 
which  the  strong  sculpture  distinguishes  this  species. 


181  UN'"  iinoN    m  HHO1  \i»HIA.  1  J7 

I.  ii  LKODADI  ran  ( topenter,  D,  >p.    1M.  in.  ligs.fji.  *'<~>t  66. 
Shell  oval-tihloiig.  moderately  elevated,  l>ack  railn  i  mindly  arched, 

<c:mvly  keeled.       Soiled  hull',  maculated  an«;  •.-.  iih  Uarki-h- 

brown. 

Lateral  areas  slight! j   raised,  cut   \\\\<>  <!  to  9  low  flat  un»''|ual 

rihlets  by  radiating  impressed  lines,  the  rihlets  made  IMU-VI  n  \>\ 
cent  rie  wrinkles  of  growth  ;  central  areas  very  mi nutcly  pitted  all 
over,  the  surface  being  something  between  aquinemirial  granulation, 
and  a  succession  of  ww-like  zigzags.  End  valves  having  fine  radiat- 
ing riblets  cut  by  some  cencentric  growth-sulci.  Mucro  in  front  of 
the  middle,  rather  prominent. 

Interior  blue-white  ;  sinus  smooth ;  sutural  plates  low,  rounded  ; 
anterior  valve  having  15-20,  central  valves  2-3,  posterior  valve  15 
narrow  slits  ;  teeth  rather  sharp,  sometimes  slightly  roughened  ;  eaves 
short,  narrow,  solid. 

Girdle  covered  with  small,  solid,  convex,  smooth  scales  (fig.  66). 

Length  25,  breadth  15  mill. 

Hakodadi,  J 

This  species,  which  was  collected  by  Wm.  Stimpson  of  the  North 
Pacific  Exploring  Expedition,  has  very  much  the  aspect  of  /.  / 
co*us  Old.  of  Australia,  the  sculpture  of  the  central  areas  being  of 
the  same  zigzag  character.  From  all  species  of  the  /.  longi- 
cymba  group,  however,  this  is  distinguished  by  its  smooth,  convex 
girdle  scales,  and  by  the  plurality  of  slits  in  the  side  insertion-plates. 
The  above  description  and  figures  are  drawn  from  part  of  the 
original  specimens. 

I.  ALBRECHTI  Schrenck.     PL  19,  figs.  70-74. 

Shell  large,  oval,  elevated,  the  dorsal  ridge  acute  ;  mucro  median, 
nearly  flat.  Reddish  maculated  with  darker,  the  interior  having 
rays  of  reddish-brown. 

Entire  surface  minutely  and  closely  punctate;  central  areas  with 
about  30  lines  of  granules  oil  each  side  of,  and  parallel  with,  the 
jugum  ;  lateral  areas  having  in  the  young  4  to  6,  in  the  adult  10  to 
12  radiating,  distantly  granose  riblets;  the  end  valves  having  50 
riblets. 

Interior:  posterior  valve  having  12,  central  valves  ?  to  3,  ante- 
rior valve  about  17  slits ;  teeth  acute,  sometimes  rugose  or  lobed  at 
the  edges,  outside  ;  sinn<  moderate,  8  to  12  dentate. 


148  OHirOKD 

Girdle  pretty  regularly  covered  with  large  narrow,  -olid,  smooth 
scales.  ( ' 

Length  40,  breadth  25  mill.,  divergence  112°. 

Hakodadi,  Japan. 

Chiton  albrechtii  SCHRENCK,  Bull.  Acad.  Imp.  Sci.  de  St.  Pelersb., 
v,  p.  511  ;  Reisen  u.  Forsch.  im  Amur-Lande,  ii,  Zool.,  p.  283,  t.  13, 
t'.  7-17. —  Chiton  (Lepidopleurus)  albrechti  E.  A.  SMITH,  Ann.  & 
Mag.  Nat.  Hist.,  (4),  xvi,  p.  115,  1875. — Lepidoradsia  granofilosus 
CPR.,  J/N. 

The  form  collected  by  H.  C.  St.  John,  R.  N.  at  Endermo  Harbor, 
Japan,  is  larger,  (length  65,  breadth  of  central  valves  28  mill.),  the 
lirations  on  the  lateral  areas  are  not  granulated,  and  all  the  valves 
are  distantly  concentrically  sulcated. 


Subfamily  CHITONIN^E. 

Lophyroidea   CpR.,-\-Acanthoidea   lophyroidea  and    Acanthoidea 

typica  CPR.,  table  of  Regular  Chitons,  1873,  and  in  Dall,  Proc.  U. 

at.  Mus.  1881,  p.  284  (1882).—  Chitonidce  and  Acanthopleuridcs 

(part)  DALL,  Catal.  Marine  Moll.  Southeast  Coast,  Bull.  37,  U.  S. 

Nat.  Mus.,  p.  172  (1889.) 

Regular  Chitons  having  the  insertion-plates  well-developed  on  all 
of  the  valves,  and  closely  grooved  or  pectinated  outside  and  at  edge. 

The  retention  of  Carpenter's  groups  Lophyroidea  and  Acanthoidea 
in  anything  like  the  limits  given  by  their  author,  is  simply  impos- 
sible. On  the  other  hand,  a  perfectly  natural  group  is  obtained  by 
uniting  these  two  groups,  after  excluding  the  "Acanthoidea  isch- 
noidea"  Cpr.,  and  the  group  Craspedochiton  Shutt.,  which  have 
special  characters  not  yet  noticed  in  print. 

Within  the  group  thus  constituted,  four  genera  having  well- 
defined  characters  are  distinguishable,  all  of  them  agreeing  in  the 
pectinated  insertion-plates,  though  varying  in  the  degree  of  pectina- 
tion. 

Synopsis  of  Genera. 

A.  No  eyes  developed  on  the  valves, 
a.  Girdle  scaly. 

Genus  XII.    CHITON  Linn.'. 

Valves  having  one  or  several  side-slits  in  each  insert  ion-plate,  and 
a  deticulated  sinus  separating  the  sutural  plates  ;  girdle  scaly,  the 


(  III 

mi. 1.^1    ami    s.»li.l,    closely    imliriral in-,    rarely   separated. 
Type  ••n/ntiix  Limn'. 

mt.   (  iinllr  willi  <lnu-t  Kristles. 

mis  XIII.     KUDO \OCHITON8huttleworth. 

Valves  having  several  side-slits  in  each  insertion-plate,  the 
suturul-plates  continuous  across  the  sinus,  which  is  represented  by  a 
mere  wave;  girdle  leathery,  heset  with  short,  stiff  bristles.  Type  C. 

no  In /is  Gray. 

AA.  Eyes  developed  on  end  valves  and  lateral  areas, 
a.  Girdle  leathery,  nude  or  nearly  so. 

Genus  XIV.     TONICIA  Gray. 

Valves  having  pectinated  insertion-plates ;  sutu nil-plates  separated 
by  a  squared  denticulate  sinus;  eyes  developed  in  more  or  less 
regular  rays  on  forward  part  of  lateral  areas  and  on  end  valves. 
Girdle  leathery,  naked  or  with  a  few  hairs.  Type  C.  elegans 
Frembly. 

aa.  Girdle  covered  with  spines  or  spinelets. 

Genus  XV.     ACANTHOPLEURA  Guilding. 

Valves  having  pectinated  insertion-plates  with  one  or  several  side- 
slits,  the  teeth  in  the  posterior  valve  directed/orward  instead  of  out- 
ward ;  sinus  denticulate  or  smooth  ;  eyes  small,  scattered  among  the 
granules  of  the  surface.  Girdle  bearing  long  calcareous  spines,  or 
closely  clothed  with  short  ones.  Type  C.  spinosns  Brug. 

Genus  CHITON  Liiiirf,  1758. 

Chiton  L.  Syst.  Nat.  edit,  x,  p.  667  (first  recognizable  species  C. 
tuberculatus*)  ;  edit,  xii,  p.  1006. — SPENGLER  Skrivin-  at'  Naturhist. 
Selsk.,  1797  (first  species  C.  tubermlnlH*}. —  LAM.M:<  K,  I'rodr. 
Anim.  s.  Vert.,  p.  90,  1799  (sole  example  fit  <s). — 

WOOD,  Gen.  Conch,  and  Index  Test.  (C  tuberculatus  the  first 
species). — GUILDING,  Zool.  Journ.  v,  p.  27,  (example,  C.  sqnamonu 
&OVfB.=tuberrulatu#).—l  rBAY,  I'.  /.  S.  1  -  >,  06.— Sun  i 

Bern.  Mittheil.  iv,  p.  72. — CARPIOM  1:1:  A-  D.M.I..  IV  .  I'.  S.  Nat 
Mus.  i,  p.  300  (1878),  type  C.  tnbercuhttus.— Not  Chit,,,,  II.  ^  A. 
AD.,  Gen.  Rec.  Moll,  i,  p.  474  (1858.) 

Lophyru*  (in  part)  POLI,  Test.  utr.Sicil.  i,  mnltn-ntri'i,  p.  2,  4,  etc. 
— H.  A  A.  ADAMS,  Gen.  K«r.  Moll,  i,  p.  46!>  -in  part.) 


150  <  HI  TON. 

'lopleurus  (in  part)  Risso,  Hist.  Nat.  Kur.  M.'rid.,  p.  267. 

Oymnoplax  GRAY,  in  The  London  Medical  Repository,  Monthly 
Journal  and  Review,  xv,  p.  234  (Jan .-June,  1*21.) 

Valves  wholly  external,  the  beak  of  the  tail  valve  median  or 
anterior;  insertion-plates  longer  than  the  eaves,  slit  into  teeth  which 
are  deeply  and  finely  pectinated,  and  typically  project  outward  on 
all  the  valves.  Girdle  covered  with  closely  imbricating,  convex, 
smooth  or  striated  scales.  Gills  extending  the  entire  length  of  the 
foot. 

Hi.<toni  "f  ti'iincs  for  Chiton.  In  the  tenth  edition  of  his  Systema 
Naturae,  Linne  includes  in  the  genus  Chiton  the  following  species: 
hi" nidus,  ("  C.  testa  sexvalvi  striata.  Habitat  .  .  "),  tubercnlatn.«, 
•itus  and  jtiun-ttttns.  Of  these  the  first,  hispidus,  is  now  univer- 
sal lv  admitted  to  be  unidentifiable,  as  no  information  or  reference 
further  than  that  quoted  above  is  given.  The  next  species  is  a  well- 
known  West  Indian  form,  and  has  been  cited  as  the  first  species  or 
tvpc  of  the  genus  by  Spengler,  Guilding,  Gray,  and  nearly  all 
authors.  Li  line's  third  species,  aculeatus,  is  apparently  unidentifi- 
able, but  probably  belongs  to  the  genus  Acanthopleura ;  the  fourth, 
pnn'-fiitns,  is  if  possible  less  recognizable  ;  and  even  its  modern  genus 
cannot  be  determined.  The  name  Lophyrus  Poli  has  been  used  for 
the  group  by  Messrs.  Adams,  but  it  can  have  no  standing  on  account 
of  the  fact  that  Poli  proposed  that  name  for  the  soft  parts  only, 
retaining  the  name  Chiton  for  the  shells,  in  accordance  with  his 
curiou.-  ~y-tem  of  double  naming.  Poli's  first  species  of  Lophyrus  is 
L.  melph'i  hidi  is  the  soft  part  of  Chiton  cinereus  L. !  Only 

one  of  Poll's  four  species  belongs  to  the  restricted  genus  Chiton. 
The  history  of  the  name  Lepidoplenrns  is  given  on  page  2  of  this 
volume.  The  history  of.  the  name  (V///////o//Au-  is  as  folh>\\ 

•ay.  in  his  article  "A  Natural  Arrangement  of  the  Mollusca 
according  to  their  internal  Structure"  (Med.  Repos.),  under   the 
h«-ad  of  •'  Or<l.  1<>  /V*///A/ro/;//o/v/,"  enumerates  the  synonyms  of  that 
term,  defines  the  order,  and  otters  the  following  arrangement: 
i'lates  placed  on  the  hack  of  the  mantle. 

1.  <  iymnoplax  or  jrymnoplacidae.     Acanthochitona.     Chiton 
facirularis.     Ix'ptochitona.     Chiton  marginatus. 

/'.    Plates  sunken  in  the  hack  of  manlle. 

2.  Cryptoplax.      Chiton  larv:eforinis." 

The  inference  from  this  would  1  e  that  Gray  intended  to  include 
in  "  <  ivmnoplax  or  irymnoplacida- "  all  Chit  ms  having  exposed 


•    Illl  I  .")  1 

val\-e>.  a  meaning  also  favored  by  the  etymology ;  but  in  I'.  / 

\^\^  he  places  (iiiiiiiinfi/ii.!-  under  <"/,//,,  a  synonym.  In 

anv  ca>e,  tin-  name  (//////;/»•///'/./•  cannot  I"  V<T  heen 

diaLrM«>sed  except  in  the  uvneral  way  <|iioted  above,  and  no-pecics 
lias  ever  hecn  rxpivss ly  deH-naled  a<  hrlnn^Ji,^  to  it.  The  name 
has  been  ii>«'il  by  <iray  only  in  the  instances  above  mentioned  and 
\va-.  MS  \ve  have  seen,  considered  a  synonym  hy  him  in  his  later 
writings;  hut  it  should  he  noted  that  the  invpre.Vihle  Kochehrune, 
still  Uflefl  <;:n,iintjt/»i.r  in  a  generic  sense,  in  order  presnmahly,  to 
disguise  his  species; — an  unnecessary  precaution,  for  his  diagnoses  of 
Chitons  generally  defy  indeiktificatioD  of  either  genus  or  species. 

In  conclusion  :  it  is  obvious  that  the  name  Chiton  must  be  retained 
for  a  group  typified  by  one  of  Linnets  original  species  ;  and  since  the 
tubereulatus  is  the  only  one  of  the  original  li.-t  which  has  been  or 
can  be  identified,  that  species  becomes  the  type  of  the  genus.  No 
other  position  on  this  question  is  reasonable  or  tenable. 

The  most  natural  primary  division  of  Chiton  is  into  two  groups; 
one  to  include  all  American  and  some  Old  World  species,  in  which 
the  mucro  is  anterior  and  the  scales  smooth,  the  other  to  include  Old 
World  species  having  the  mucro  subcentral  and  the  scales  striated. 
As  this  division  is  based  upon  characters  not  always  easy  to  see,  the 
following  division  into  sections  is  more  convenient. 

Section  CHITON  (restricted.) 

Median  valves  having  a  single  slit  in  each  insertion-plate;  sinus 
generally  denticulate ;  scales  closely  imbricating. 

Section  RADSIA  Gray. 

Median  valves  having  two  or  more  slits  in  each  insertion-plate. 
Section  SCLEROCHITON  Cpr. 

Median  valves  having  a  single  slit  in  each  insertion-plate  ;  teeth 
of  tail-valve  tending  forward;  sinus  smooth;  scales  of  girdle 
separated. 

Section  CHITON  s.  str. 

Artificial  key  to  specie*  of  Chiton. 

A.    LATERAL  AREAS  RADIALLY  SCULPT i  KI:I>. 

a.  Central  areas  having  longitudinal  riblets. 

b.  Sides  and  ridge  of  central  areas  both  sculptured. 


>  <  m  r<>.\. 

c.  Urabo  of  tail  valve  distinctly  in  front  of  the  middle. 
d.  Ril>let>  of  lateral  areas  rather  smooth  and  fine. 
e.  Dotted  or  spotted  with  Mm-. 
/.  Large,  black,  dote  Bmall, 

ff.  Small:  dots  large, 
ee.  Concentrically  Hneated  with  brown  or  dark,       cumhufi. 
eee.  Unicolored  or  blotched. 

/.  17  slits  in  head  and  tail  valves  together,      perviridis. 

ff.  22-24  slits  in  head  and  tail  valves  together,        quoyi. 

fff.  35  slits  in  head  and  tail  valves  together,         subfuscus. 

ffff.  30  slits  in  head  and  tail  valves  together,          bowenii. 

dd.  Riblets  of  lateral    areas   granulose,  irregular,  or   much 

forking. 

e.  Lateral  areas  with  3-4  rows  of  pustules,  granosus. 

ee.  Lateral  areas  with  forking  or  meshing  riblets. 

/.  Riblets   8-10,   fine ;  slits   in   head    and    tail    valves 
together  about  40,  i-iri/ulatus. 

ff.  Riblets  coar&er,  netted  ;  slits  fewer,  stokesii. 

Umbo  of  tail  valve  about  central. 
d.  Mucro  depressed,  slope  behind  it  hardly  concave, 

pellisserpentis. 

dd.  Slope  behind  mucro  very  concave,  burmmttin. 

bb.  Central  areas  with  a  smooth  band  or  triangular  on  ridge  of 
each  valve. 
Murro  in  front  of  the  middle. 

i-entral  areas  curved  or  converging, 

e.  Lateral  areas  sparsely  pustulose-lirate,  viridis. 

ee.  Lateral  areas  with  interrupted  or  netted  lira-. 

tubereulattu, 

</</.   Riblets  of  central  areas  parallel  or  diverging  forward. 
e.  Lateral  areas  and  end  valves  pustulose,  granosus. 

ee.  Lateral  areas  and  end  valves  granose-ribbed, 

ofmaKeulatut. 

eee.  Lateral  areas  1  irate,  nigrovircns,  perviridis,  densi  I  trains. 
Muero  about  ••entral. 
d.   Lateral   areas   with    low.  smooth   riblets,  olh"irc us,  (jereus, 

affin  I*. 

dd.  Lateral  areas  with  feebly  ^ranox-  ril.l«-t>,  tusul'ir!*. 

ddd.  Lateral  areas  with  Lrrano>«-  or  noilo.-e  ribs. 

•.    Lateral  areas  with  o-l,  pleura  '2~>  riblets,  <Ki€ 


•  III  i 

ee.   I.ateml  MT6M  uith  L'   :!.  pleuni   1  1  rihl«-K 

aa.  <  entral  :uv:is  .-moot!).  lacking  longitudinal  ril 

b.    Fnd  valves  un-aiio.-r-lirale  or  pu-tuloae. 

C.    Fnmt  ot'di:i;r<m:il  line  obviously  wrinkled  or  j»itti-«l. 
d.  Shell  and  girdle  uniform  dark  LI  ru«/ 

•itl.  Shell  variegated,  gird!  -mated,  afotrt. 

'/(A/.  Shell  or  irinllr  vnii'-l.  BOalei  smooth,  viY/' 

l-'roiit  of  (liiiLronal  line  smootli. 

il.  I'ustulcs  .-<';itifi-nl  :  >iiril  and  girdle  UDiform  blackUb, 

mar 
'/(/.  Finely  Ix-adcd  ;  ihell  and  girdle  banded,          .^/////?no«««. 

66.   End  valves  finely  striated. 

C.  Shell  oblon.ir.  divergence  about  110°. 

Shell  elongated  :  divt-rp-m'''  about  98°.  f><»< 


AA.    LATERAL  AREAS  SMOOTH  OR  CONCI:VI  1:1-  M  .1  .v  w  n.i'irRED. 

a.  Whole  surface  smooth. 
b.  Mucro  near  the  anterior  margin. 

c.  Color  black  and  olive-yellow,  with  snowy  lines,  (ilhu/in- 
cc.  Purple  or  olive  mottled. 

d.  Sutural-plates  within  dark-blotched   at  base;  sinus  nar- 
row, ''j'ttiift. 

d<L  Suttiral-plates  within  not  blotched;  sinus  wide, 

marmoroto*. 

bb.  Mucro  central,  tidipa. 

aa.  Central  areas  longitudinally  sculptured,  (species  not  tabulated.) 

West  Indian  species. 

Mainly  large  forms,  with  smooth  scales  and  notably  anterior 
mucro.  They  are  closely  allied  to  the  species  of  the  Panamic 
region. 

C.  TUBERCULATU8  Linne.     PI.  :53,  figs.  58,  59,  60. 

Shell  oval-oblong,  rather  elevated,  carinated,  thoide-slope-  nearly 
straight.     Color  varying  from  light  olive  to  dark   Driven    <>r  dark 
olive-brown,  unicolored  sometimes,  but  generally  speckled   on   the 
side-areas  and  end-valves,  often  clouded  on  tin-  central  an 
of  the  valves  having  a  dark  stripe  on  the  ridge. 

Lateral  areas  raised,  sculptured  with  about  -\eord-like  radiatm- 
riblets,  which  are  sometimes  subcontinuous,  but  usually  are  much 


154  «  IIITON. 

interrupted  :in<l  broken,  and  bearini:  :i  few  low  tubercles.  Central 
areas  smooth  along  the  ridge,  the  sides  sculptured  with  longitudinal 
riblets  curving  inward,  becoming  coarser  outwardly  and  diverging. 
End  valves  closely  tuberculate  all  over,  the  pattern  resembling  that 
<•!' an  ciiLrine-turned  watch  case.  Umbo  of  tail  valve  near  the  front 
margin. 

Interior  blue-green,  very  smooth,  the  snttiral  plates  lighter:  sinus 
narrow,  toothed.  Anterior  valve  having  13,  central  valves  1,  pos- 
terior valve  14  slits;  teeth  blunt,  pectinated.  Slit-rays  hardly  ornot 

Girdle  white,  buffer  light  green,  alternating  with  patches  of  dark 
green  or  blackish.     Scales  rather  coarse,  convex,  polished. 
Length  60,  breadth  33  mill,  (average  Jamaica  specimen.) 
Length  90,  breadth  55  mill,  (specimen  from  Nassau,  N.  P.) 

Bermuda,  Florida  and  Texas  to  Trinklul. 

Chiton  tuberculatus  LINNE,  Syst.  Nat.  x,  'p.  667  (1758). — 
HANLEY,  Shells  of  Linn.,  p.  12. —  Chiton  squamosus  BORN,  Test. 
Mus.  COBS.  Vindob.,  p.  5,  t.  1,  f.  1. — CHEMX.,  Conchyl.  Cab.  viii, 
f.  788-790.— REEVE,  Conch.  Icon.,  t.  3,  f.  16.— HADDOX,  Chall. 
Polyplac.,  p.  20,  and  of  all  modern  authors.  NOT  Chiton  sqmnnosus 
Linne. —  Chiton  undatus  SPENGLER,  Skrivter  af  Naturhist.  Selska- 
bet  iv,  p.  68  (1797).—  C.  bistriatus  WOOD,  Gen.  Conch.,  p.  7  (1815). 
— /  C.  tessellatm  WOOD,  1.  c.,  p.  23. 

This  species  has  been  generally  considered  to  be  the  squamosus  of 
Linnreus,  but  that  the  Linnsean  name  belongs  to  another  species 
must  be  regarded  as  established.  The  references  quoted  by  Linna-us 
in  the  tenth  edition  of  [the  Systema  clearly  show  that  this  is  the 
species  which  he  culled  tuberculatus.  In  the  twelfth  edition  other 
references  not  applicable  to  the  species  are  added ;  and  the  figures 
given  by  Chemnitz,  Horn,  and  others  under  the  incorrect  name 
"squamosus"  have  caused  subsequent  authors  to  adopt  the  latter 
nan 

This  species  is  the  commonest  Chiton  of  the  W--i  Indies,  and  is 
readily  known  by  its  (typically)  strong,  curved  ribs  and  peculiar 
sculpture  upon  the  end-valves,  which  Reeve  aptly  compares  to  that 
of  A  lathe-turned  watch  case.  It  is  extremely  difficult  to  draw  a 
line  between  this  species  and  ( '.  n^lmi/i^  of  Keeve;  so  difficult,  in 
fa< -l,  that  I  have  be«-n  unable  to  satisfactorily  distribute  a  portion  of 
the  specimens  In  i'.n  me  between  the  t\\...  Linna  us  describes  tu- 


•  Ill 

bereulatus  MS  nfrt'ii-rii/i'fil ;   and  oddly  enough,  mie  of  1  In-     • 
collected  l.y   I  >r.  II.  Sharp  at  Toba-"  i-  aUo  apparently  .-«-v.-n-\  alved, 

having  two  of  the  valvei  linnly  loldered  lit  of  an 

early    injury.      It    is   likely  that    the   B6VOT    and     -ix-valved   (  'hit-. us 
:ihed  by  early  author.-  were   partly  abnormal   specimen-  of  tins 
c'haraeter.  and  the    rest    \v  iv    (minded    upon    careless   and    MOO] 

Bgur 

Color-var.  Color  a  uniform  dull  blackish  ;  rihlets  of  the  central 
area-  finer  and  coim-r^ini:  near  to  the  median  line.  Area  behind 
the  sinus  in-ide,  and  the  slit-rays  solid,  not  spongy  or  pon.u-. 

nuda. 

I  have  8681)  a  -reat  number  of  specimens,  but  mostly  BO  <-roded 
that  the  permanence  of  the  characters  could  not  be  decided. 

Yar.  ASSIMILIS  Reeve.     PI.  33,  figs.  61,  62. 

Fawn  colored,  with  white  dots  on  the  lateral  areas,  the  ctirina 
handed  with  brown  ;  girdle  light  green.  Central  areas  «mtj>tured 
with  very  fine,  close  riblets.  Interior  having  the  >lit-rays  and  the 
area  behind  the  sinus  porous. 

St.  Thomas  to  Barbados. 

Chiton  f/.Wm/7/x  KI:I:VK,  Conch.  Icon.,  t.  14,  f.  76  (right  hand 
figure)  ;  f.  77b.  (March,  1847.) 

Color-var.  ater.  (pi.  33,  fig.  63).  Shell  having  the  close  fine 
sculpture  of  assimilis,  but  black  in  color,  dark  green-blue  inside. 

St.  Kitts  (Rush)  ;    Tr'>ni<L,<l  (Sharp.) 

C.  SQUAMOSUS  Linne.     PI.  85,  figs.  80,  81,  82. 

Shell  oblong,  elevated  or  rather  depressed,  carinated,  the  side- 
slopes  somewhat  convex.  Surface  of  lateral  areas  minutely  headed- 
central  areas  smooth  ;  lusterless.  Color  butt' (pale  or  deep  in  t 
the  central  areas  regularly  and  oonspicuotuly  striped  longitudinally 
with  gray  or  black,  most  valves  having  a  wider  dark  blotch  on  each 
side  of  the  keel,  and  a  series  of  spots  along  the  back  edge. 

The  lateral  areas  and  en<\  vtlues  are  raised  n/i<!  sculptured  trith 
radiating  rows  of  fine  beads,  the  number  of  rows  increasing  by  inter- 
polation ;  and  under  a  lens  the  surface  is  seen  to  be  ininntt'lij  j>uitct>tte. 
Cf-nfrn/  urcua  not  sculptured,  save  for  inconspicuous  growth-lines. 
MIKTO  of  posterior  valve  near  the  front  margin. 

Interior  dark  blue-green,  the  sutunil  plates  lighter.  Sinus  rudely 
denticulate.  Anterior  valve  having  12,  central  valvt  >  1.  p  >-terior 


!•"•»'>  <  IIITON. 

valve   l:J  slits.     Kavos  narrow,  .-hort.  somewhat  spongy;  sinus  and 
slit-rays  hardly  porous.     Teeth  pectinated. 

Girdle  alternately  light  green  and  whitish,  covered  with  smooth 
convex-flattened  scales. 

Length  60,  breadth  .".2  mill. 

Len-tli  4:»,  breadth  28  mill. 

Cuba,  Jamaica,  St.  Thomas  and  St.  Croix,  West  Indies. 

Chiton  squamoms  LINNE,  Mus.  Ulricae,  p.  465  (1764).  —  Chiton 
niosus  L.,  Syst.  Nat.  xii,  p.  1107.  —  SpENGLEBSkrivter  at'  Natur- 
historie-Selskabet  iv,  p.  67,  t.  6,  f.  2  (1797).—  HANLEY,  Shells  of 
LiniKeus,  p.  15  (1855).  NOT  C/iiton  squamosus  of  authors.  —  Chiton 
BPENGLEB,  ].  >•..  p.  68  (a  depressed  form;  see  Chemn.  viii,  f. 
792,  793).  —  Chiton  scaber  variegatus  CHEMN.  Abh.,  p.  31,  t.  1,  f.  3  ; 
Conchyl.  Cab.  viii,  p.  276,  t.  94,  f.  792,  793.—  Chitonfasciatus  WOOD, 
Gen.  Conch..  IS]."),  p.  10,  t.  1,  f.  4,  5  (excl.  syn.).  —  SOWB.,  Conch. 
Illii.-tr..  f.  1  .y;.—  SHUTTLW.,  Bern.  Mittheil.  1853,  p.  74.—  Chiton 
cheinnit-ii  PKR.,  Krit.  Register  zu  Mart.  u.  Chemu.,  p.  78,  1840.  — 
Chiton  marmorem  REEVE,  Conch.  Icon.,  t.  12,  f.  64  (not  of  Chemn. 
nor  Fabr.) 

This  species  is  colored  in  much  the  same  fashion  as  some  striped 
forms  of  C.  marmoratus,  and  it  also  agrees  with  that  species  in  the 
smooth  central  areas;  but  the  dullness  of  the  surface  and  the 
minutely  beaded  lateral  areas  at  once  separate  the  two  forms. 
Specimens  vary  greatly  in  degree  of  elevation  and  consequently  in 
the  size  of  the  angle  of  divergence. 

LiniKeiis  gives  an  unusually  full  description  of  this  species,  amply 
sufficient  to  distinguish  it  from  the  shell  which  Born,  Gmelin,  and 
later  authors  confused  with  it.  Spengler  correctly  identified  it  in  his 
monograph  of  17'.»7,  and  gave  a  most  excellent  figure  and  a  good 
ription.  Hunley  found  Linnaeus'  original  type  still  preserved  in 
hi-  eollertion,  but  the  C.  squamosus  of  authors  is  not  present  there. 
It  should  hi-  noted  that  Linnaeus'  specific  names  of  Chitons  were 
intended  to  In-  descriptive  of  the  girdle*,  not  the  valves. 


rjUDIfl  Spengler.     PI.  33,  figs.  64,  (if),  (Hi,  67. 
Shell  oval,  moderately  elevated,  carinated,  side-slopes  slightly  con- 
vex.    Color  varying  from  gray-white  to  olive,  irregularly  marked 

on  tin-  central  area-  ..r  on  the  rid«jo  with  blackish  :  some!  lines  hlack- 
hrnwn  all  o\ 


(ii i  I..N.  157 

Lateral  ATOM  strongly  raised,  :iml   wulpturtd  »•////  • 

low    r'nli'itint/    rih.t   Item-ing    nf    irrcgn/ur    or   regular    inh-rrn/.-- 
rnumh'd  j.  I   tin   ,-<iili'<iti><g    /'/'Ax,   tli.-  i>  ,r    ///,,/ 

rior  lionlrr  of  eacb    valv  gen<  nil;. 

ticulated.     OwUro/ oraoi  tmoo^i  hi  the  >/m/<//v,  but  tm^pfurtfd  <i/<tng 

///»•  tlingmi'il  linen  with  <t   ncrien   <>(  nlmrt   rilm   f»'tit    in    ///»•  .<//'////•  o/'  // 

reversed  s  Mud  valves  l)c;irinLr  radiating  series  oft  aber- 

cles,  or  with  only  a  lr\\  scattered  tiil)«'i-clcs.       Murro  uc:ir  the   front 

margin. 

Interior  light  b/nc  or  light  green.  Sutural  |ilat«-s  lii:lit«T,  highly 
arclu-d,  tlie  sinus  deep,  narrow,  angular,  the  straight  dentic- 
ulate portion  from  •]  to  i  the  length  of  a  sutural-platc.  Anterior 
valve  having  13,  central  valves  1,  posterior  valve  12  slits. 

Girdle  alternately  whitish  and  brown  or  green,  finely  scaly. 

Length  36,  breadth  22  mill. 

St.  Thomas  ami  M.  <  ',•<>!.,•  (Swift)  ;  Jamaica. 

Chiton  *(]n<nnosus  denticularis,  etc.,  ('HUM MI/,  Conchy  1.  Cab.  x, 
p.  372,  t.  173,  f.  1689.—  Chiton  viridis  SIM:N«,LI:I:,  s'krivu-r  af 
Naturhistorie-Selskabet.  iv,  p.  70,  t.  6,  f.  5  (1797). — WOOD, 
General  Conch.,  p.  15  (1815). —  CAifam /oveo/atu*  SOWERBY,  Charles- 
worth's  Mag.  of  Nat.  Hist.  1840,  p.  290;  Conch.  Illustr.,  f.  60.— 
Ki:i:\  i:,  (Jonch.  Icon.  t.  6,  f.  28. —  Chiton  costatus  C.  B.  AD.,  Proc. 
Bost.  Soc.  Nat.  Hist.  1845,  p.  8. — Chiton  (Lophyru*)  gemmnlatus 
SHUTTLEWORTH,  Bern.  Mittheil.  1853,  p.  75. 

Doubtful  references: — Chiton  squamosus,  testa  septen-valvi-striata, 
etc.,  CHEMNITZ,  /.  c.  x,  p.  374,  t.  173,  f.  1690,=  F<m'etef  af  Chiton 
undatus,  SPENGLER,  Skrivter  af  Naturhistorie-Selskabet,  iv,  p.  69 
(1797). —  Chiton  tessellatus  WOOD,  Gen.  Conch.,  p.  23  (1815).— 
Chiton  excavatus  (Gray)  SOWB.,  Conch.  111.,  f.  131  (never  de- 
scribed.) 

This  species  is  well  distinguished  by  the  series  of  short  CM  i 
wrinkles  along  the  diagonal  latero-posterior  edges  of  the  other 
smooth  central  areas,  and  by  the  sutural  denticulation,  when  this  is 
developed,  which  is  by  no  means  always  the  case.      The  diagnostic 
features  of  the  species  are  stated  with  great  clearness  by  the  Danish 
naturalist  Spengler,  and  also  by  Chemnit/,  but  the  figures  given  by 
them  are  poor.     There  is  great  variation  in  the  development  of  the 
pustules  upon  the  lateral  areas  and  end  valves. 


158  <  IIITON. 

M:MORATUS  Gmelin.     PI.  34,  figs.  72,  73,  74,  7~>,  70. 

Shell  oval,  rather  elevated,  the  dorsal  ridge  varying  from  roundly- 
angular  to  distinctly  carinated;  side-slopes  convex  or  straight.  Sur- 
face smooth,  polished.  Color  varying  from  olive  to  dark  brown  or 
purple-brown,  variously  marked  with  darker  spots  or  blotches  and 
liirht  longitudinal  stripes  or  lines. 

The  lateral  area-  arc  a  little  raised  ;  the  whole  surface  showing  a 
very  minute  quincuncial  pattern  of  granulation  under  the  lens,  and 
marked  with  inconspicuous  growth-lines.  Mucro  close  to  the  front 
edge  of  the  tail-valve,  as  in  C.  Icevigatus. 

Interior  blue-green,  each  valve  often  having  darker  or  olive  pos- 
terior rays.  Sinus  deep,  angular,  having  a  jagged  convex  row  of 
denticles,  half  as  long  as  a  sutural-plate.  Anterior  valve  having  11- 
14,  mitral  valves  1,  posterior  valve  13-17  slits;  teeth  deeply  finely 
pectinated.  Eaves,  slit-rays  and  triangle  behind  the  jugal  sinus 
very  porous. 

Girdle  alternately  blotched  with  green  and  light  blue. 

Length  56,  breadth  32  mill. 

Length  48,  breadth  26  mill. 

Texas  (Dall)  ;  Bermuda  (Heilprin)  ;  Jamaica  (Cpr.)  ;  Cuba  ;  St. 
Thomas  (Swift)  ;  St.  Croix;  St.  Vincent  (Sharp)  ;  Barbados  (Rush)  ; 
Carthagena,  U.  S.  Columbia  (Krebs.) 


Chiton  marmoratus  GMEL.,  Syst.  Nat.  xiii,  p.  3205.—  (Chiton 
marmoreus  CHEMNITZ,  Conchyl.  Cab.  viii,  p.  282,  t.  95,  f.  803-805. 
Not  C.  marmoreus  REEVE).  —  C.  marmoratus  Sows.,  Conch.  Illustr., 
f.  148-150.—  REEVE,  Conch.  Icon.,  f.  6.—  SHUTTLW.,  Bern.  Mittheil. 
1853,  p.  74.—  DALL,  Cat.  Moll.  S.-E.  U.  S.,  p.  172.—  C.  scarabceus 
REEVE,  Conch.  Icon.,  t.  12,  f.  66. 

This  species  is  excessively  variable,  but  with  all  its  variety  I  have 
seen  no  specimens  having  the  pattern  of  the  West  Mexican  C. 
l&vigatus  and  articnltifns.  The  following  color-patterns  are 
commonly  met: 

1.  Entire  surface  of  valves   blackish-brown.     This  is   not  an 
uncommon  form,  being  the  C.  scarabcRus  of  Reeve. 

2.  Olive,  with  fine  flecks  and  lines  of  whitish,  becoming  confluent 
toward  the  middle. 

3.  Either  purple-brown  or  olive,  having  longitudinal  zebra-like 
stripes  on  the  side-slopes. 


CHITON, 

This  -pi-firs  is  amply  dislin.Lrni.-hed  from   1'.  /nrlf/'ifn.--  hv  tin-  wider 
sinus,  dillrtvnt  Ooloriagj  and  l>y    tlir  iniirli  more  porous  lines  |f 
iiiLT  toward  llir  .-Ills,  and  (lir  eon>piriiou>ly  pomii-  triaiiL'l'    under  tin- 
dorsal  ridi:r  of  each  valve,  as  shown  in  li: 

Species  of  the  West  coast  of  the  Americas. 

This   is   a    natural  jrroup  of  lar.Lre  species,  character  i/fd   bv  the 
generally  somber  color,  large  smooth  scales,  and  anterior  nuiero. 
l!<td.*!'t  is  a  tangent  from  this  circle  of  speei 

C.  LJEVIGATUS  Sowerby.    PL  34,  figs.  68,  69,  70,  71. 

Shell  oval,  subdepressed  or  elevated,  carinated,  the  side-slopes 
somewhat  convex.     Surface  smooth.      Colors  soft  and  blended, 
ing  from  purple-gray  to  olive,  lighter  in  the  middle,  where  there  are 
three  irregular  longitudinal  series  of  black  or  dark  blotches  ;  back 
edge  of  each  valve  often  articulated  with  light  and  dark  spots. 

The  lateral  areas  are  a  little  raised  ;  whole  surface  polished,  show- 
ing a  microscopic  quincuucial  granulation  under  the  lens.  Mucro 
unusually  close  to  the  front  edge  of  the  tail  valve,  almost  marginal. 

Interior  dark  green-blue  ;  the  sutural  plates  lighter  but  having  a 
large  dark  green  or  blackish  blotch  at  the  base  of  each.  Sinus  deep, 
si  jiiare,  with  a  convex  row  of  jagged  teeth.  Anterior  valve  having  17, 
central  valves  1,  posterior  valve  21  narrow  slits;  teeth  blunt,  deeply 
laciniate  ;  eaves  short,  narrow,  spongy. 

Girdle  wide,  tessellated  with  alternate  light  and  dark. 

Length  55,  breadth  38  mill. 

Length  85,  breadth  55  mill. 

Gulf  of  California  to  Afif 

Chiton  lavigatus  Sown.,  P.  Z.  S.  1832,  p.  ~M  ;  Conch.  Illustr.,  f. 
18*.  —  REEVE,  Conch.  Icon.,  t.  7,  f.  35.  —  Chiton  artictthttiis  Sowi:i:i:y. 
P.  Z.  S.  1832,  p.  59;  Conch.  Illustr.,  f.  18.—  Ki  i  h.  Icon., 

t.  2,  f.  7. 

Sowerby's  description  of  Icevigatus  precedes  that  of  »//7/V;/A////x  in 
the  P.  Z.  S.,  and  since  the  two  forms  prove  to  belong  to  one 
species,  the  former  name  must  be  accepted.  Fig.  69  represents  the 


There  is  considerable  variation  in  the  decree  of  elevation  and  in 
the  contour,  but  the  extremes  seem  to  be  connected  most  intimately 
by  specimens  intermediate  in  form.  This  species  has  a  general 


160  <  HITON. 

resemblance  to  the  West  Indian  smooth  Chiton,  (\ 
but  it  differs  in  the  plan  of  coloring  both  inside  and  out,  the  West 
Indian  species  lacking  the  dark  blotches  upon  the  bases  of  the 
sutural-plates,  which  are  so  characteristic  of  Icevigatus.  The 
marmoratus,  morever,  has  a  proportionately  wider  sinus,  the  straight 
toothed  space  between  the  sutural-plates  being  half  as  long  as  each 
plate,  whilst  in  Icevigatus  it  is  only  one-third  as  long.  This  last 
character,  together  with  the  internal  coloring,  will  always  distinguish 
the  two  species. 

C.  ALBOLINEATUS  Sowerby.     PL  32,  fig.  57. 

Shell    oblong,    parallel-sided,    moderately    elevated,    carinated, 
smooth ;  lateral  areas,  end  valves  and  dorsal  keel  black,  marked  with 
-•i-nile  radiating  lines.     Sides  of  the  central  areas  light  olive- 
green,  some  of  the  valves  occasionally  black. 

The  lateral  areas  are  a  little  raised;  entire  surface  most  minutely 
granulated  in  the  usual  quincuncial  pattern.  Beak  of  posterior 
valve  anterior. 

Interior  light  blue,  the  sutural  plates  paler.  Anterior  valve 
having  15-16,  central  valves  1,  posterior  valve  16-17  narrow  slits ; 
teeth  strongly  pectinated.  Eaves  narrow,  short,  spongy.  Sinus 
denticulate. 

<  iirdle  firm,  blue-gray,  compactly  covered  with  convex-flattened 
polished  imbricating  scales. 

Length  35,  breadth  18  mill. 

Todos  Santos  Bay,  L.  California  (R.  E.  C.  Stearns) ;  Mazatlan 
(Cpr.) ;  Acapulco  (Ruschenberger.) 

C.  albolineatus  SOWB.,  Zool.  Journ.  iv,  p.  368 ;  in  Zool.  Beechey's 
Voy.,  p.  149,  t.  40,  f.  4  ;  Conch.  111.,  f.  39.— C  albUineatns  Ri 
Conch.  Icon.,  t.  2,  f.  11. — Lophyrus  albolineatus  CPR.,  Maz.  Cat.,  p. 
191. 

The  apparently  smooth  surface  and  the  conspicuous  snowy  stripes 
render  this  a  very  distinct  specific  type.  Each  scale  of  the  girdle 
when  examined  under  a  lens  is  seen  to  be  of  a  delicate  blue-green 
color,  edged  broadly  with  white. 

C.  MAONIFICUS  Deshayes.     PL  30,  figs.  23,  24. 

Shell  large,  oval,  moderately  elevated  or  somewhat  depressed,  the 
dorsal  ridge  indistinctly  carinatrd.  -id. --lopes  a  little  convex.  Color 
Murk,  H'itli  minute  blue  dots  scattered  rather  thickly  over  the  valves; 
girdle  bla<-k. 


.in  1 1 ;  I 

Tin-  lateral  .  \  n-\    lilt  !<•  rai-ed,  and  sculpt  im-il  wit  li  a 

10  small    suholxoletc    radiating    rililets  :   central    area-    «•!«.. -«-ly   and 
linely    sculptured    with    longitudinal     nUeis    separated    l.y   «!• 
interstice-.      I'.^terior  valve  having  tin-  limbo  near  tin-  front  DUU 
tlie  slope  behind  it  straight. 

Interior    light    l)lue;    sutural    plates    wide;    sinu-   square,  finely 
toothed.        Anterior    valve   bavin-'   '•>    1-,  cent  ral  valve-  1.    post 
valve  I'J    11  slits;   teeth  stout,  blunt,  deeply  pectinated.      Kave- 
sliort  and  narro\v,  spun. 

(iirdle  -  lig.  -\  >  strong,  covered  with  .shining,  convex,  imbricating 

seal 

Lentil)  '.)•">,  breadth  60  mill.;  divergence  120°. 

Valparaiso,  C '//  /'//'. 

Chiton  mitgnijicus  I)n.,  Diet.  Class,  des  Sc.  Nat.  xii,  p.  4-V>  : 
I-jicycl.  ^Feth.,  p.  680;  Lam.,  An.  s.  Vert.,  ed.  Dh.,  vii,  p.  498.— 
J{I-:I-:VK,  Conch.  Icon.,  t.  1,  f.  3. —  Chiton  latus  SOWERBY,  Catal.  Sh. 
Tankerv.,  appendix,  p.  v,  (not  Ch.  latus  Lowe). —  Chiton  olivaceus 
FREMIM.Y.  Zool.  Journ.  iii,  p.  199,  Suppl.  pi.  16,  f.  4. —  Cliiton 
nfrlnhi*  UAUNKS,  Amer.  Journ.  of  Science  vii, p.  70,  t.  3,f.  l.(1824). 
Not  ('.  ttriiifns  of  authors. 

This  large  olive-black,  blue-dotted  species  is  remarkable  for  the 
evenness  and  smoothness  of  its  sculpture.  It  is  an  unusuallv  hand- 
some Chiton. 

C.  MURRAYI  Haddon.     PI.  29,  figs.  15-21. 

Shell  apparently  smooth,  but  really  very  closely  and  finely 
striated,  the  striae  being  roughened  or  interrupted  ;  greatly  depre 

Anterior  valve  with  radial  stria-;  under  surface  with   eleven   dis- 
tinct square  slits,  radial  grooves  distinct  and   perforated;  teeth  of 
insertion     plate    serrate.         Intermediate    valves   narrow,   tlatt. 
non-carinate,  with  sharp  depres.»ed  umbo,  surface  stria?  longitudinal 
in  central  areas,  radial  in  the  lateral  areas;  lateral   areas  distinct, 
with  slight-concentric  ruga-,  and  with  three  or  four  >carcely  apparent 
peripheral  radial  ridges,  which  die  away  toward  the  apex  ;  sutural 
laminae  shallow,  a  single  lateral  slit,  lateral  insertion   plates  Ben 
juguni  with  nine  rounded  teeth,  the  central  beiinr  verv  small.      Pos- 
terior   valve   flattened,  slightly     umhonatc,    stria-  longitudinal  on 
the  anterior  area,  radial  on  the   posterior  an  -a  :   under  surface  with 
seventeen  distinct  slits,  teeth  serrate  :  jugum  finely  toothed. 
11 


•    II!  I 

Color,  upper  surface  ground  color  of  shell  a  greenish-  -rhtly 

clouded  with  dark  brown  and  black ;  umbones  lighter  ;  on  eacl 
of  the  latter  the  ground  is  yellowish:  whole,  wrimr  «],ritik!fd  with 
pale  blue  spots,  which  are  bounded  externally  by  a  black  line;  on 
••i-ntral  areas,  the  spots  run  in  irregular,  oblique,  hackwardly 
diverging  lines,  and  have  a  slight  tendency  to  confluence,  but  on  the 
lateral  areas  and  terminal  valves  the  spots  are  irregularly  scattered; 
under  surface,  pale  sea-green,  darker  along  the  jugum,  and  with  a 
dark  spot  at  the  umbones  of  the  terminal  valves. 

Girdle:  upper  surface  with  large  imbricate  scales,  of  which  the 
exposed  portion  is  smooth,  the  hidden  portion  being  usually  finely 
striated  longitudinally ;  color,  dark  green,  with  a  tendency  to  form 
darker  bands  opposite  the  valves;  in  the  angles  between  the  valves 
a  few  of  the  scales  are  paler  and  yellowish  in  color;  under  surface 
with  long  narrow  oblong  white  scales  arranged  in  transverse  series. 

<  Jills  extending  along  the  whole  length  of  thefoot,  about  fifty- live 
<>r  >ixty  in  number. 

Length  12'5,  breadth  7%3  mill. 

The  following  Chitons  also  have  blue  spots:  Chiton  magnificus 
Desh.  and  Chiton  dvrjuncttu  Fremb.  The  latter  is  also  from 
Valparaiso,  but  it  would  be  impossible  to  mistake  these  for  Chiton 
murrnij'i.  Superficially,  this  species  bears  some  resemblance  to 
loplcurut  lentiginosus  Sow.  (G.  B.  Sowerby,  1840,  Charles- 
worih's  X.  S.  London's  Man.  Xat.  Hist.,  and  Conch.  Illust.,  1841, 
figs.  120,  121 ;  Reeve,  Conch.  Icon.,  1847,  pi.  xxiv,  fig.  165,=  Chiton 
letatu*  KKAUSS,  Die  siidat'rikanischen  Moll.,  1848,  pi. 
iii,  tiir.  -) ;  but  apart  from  the  generic  distinction,  Suwerhy's  species 
can  be  distinguished  by  the  perfectly  smooth  shell,  inconspicuous 
lateral  an  as.  paler  color  of  the  shell  generally,  and  absence  of  the 
external  black  border  to  the  blue  spots.  I  have  given  myself  t  Ill- 
pleasure  of  dedicating  this  pretty  and  distinctive  little  Chiton  to  Mr. 
John  Murray  of  the  Challenger  Expedition.  (Haddon.') 

Valparaiso,  Chili  on  the  shore. 

Chi  \\  .  Challenger  Polyplac.,  p.  1>1,  t.  1,  f.  7; 

t.  3,  f.  la-le. 

• 

C.  8UBFU8CU8  Sowerby.    PI.  38,  figs.  19,  20,  21,  22. 

Shell    <  h-vated,    carinated,     the    sidr-slopes     nearly 

straight.     Surface  rather  shining.     Color  dark  olivi-hrown.  or  olive- 


raved  will)  brick-red,  (or  "  copperat-jpreen  or  reddish,  i 

ss  tlamed  \villi  jet-l>lael 

Tin-    lateral  -in.  -\\hai  '.  itli 

11  inn  '  -  "  ,    ii'/ti'-lt    « 

rnpted    by    grow  th-lines.      Central    I  dptim-d    \,\ 

irniwth-wrinkles.  and  by  //m'   /»n</iti<(li>i<il   flirentlx.    ir/n'r/i  nrr,  <;• 
nil]!  ol>*«/rtr  "i-  ,ilw)it  or/-/*/  mi  f/inj;-nnt  of  //<>-   dnrnnl   r'i<\<ji>   of 
Wive,      Kml  valves  having  radii  like  tin-  l:it«-r:il  areas,  their  uneven- 
ness  iriviiiL:  the  valve  a  superficially  pitted  or  tinely  netted  apt 
anee.      l>eak  of  tail  valve  near  the  anterior  margin. 

Intoriur  pale  l)Ini>h,   the  sutural-plates   whiter.       Anterior  valve 
having  15,  central    1,   postrrim-  valve  20  slits;  teeth  rather  sharp- 
I,  strongly  crennlated  inside  and  out;  sinus-area  spongy  ;  slits 
ami  slit-rays  coarsely  sponiry.     Kaves  short. 

Girdle  densely  covered  with  fine,  smooth,  convex,  shining,  black 
or  olive-black  scale-. 

Length  4'J,  width  '24  mill.;  divergence  110°. 

Island  of  Chiloe  (Cuming)  ;   Chili. 

Chiton  *nhi'n.<cn.-<  SOWERBY,  P.  Z.  S.   1832,  p.  26.—  CA/Vo//  .<triatus 
Bttrnw,  Si.wi;.,  Com-hol.  Illustr.,  f.  3,  41  (excl.  synoii.  i.  —  ('. 
l!i:r.vi:.  Conch.  Icon.,  t.  1,  f.  36.     Not  Chitim  *triutu.< 


This  species  is  closely  allied  to  C.  mmjnifn'U8j  but  differs  in  being 
smaller,  narrower  and  more  elevated,   in    lacking  l)lue  dots,  and   in 
the  partial  obsolescence  of  the  longitudinal  striation  of  the  central 
areas.     Figure  19  represents  the  form  which  judging  by  his  measure- 
ments Sowerby  considered  typical.     He  aftewanl   united  o//V 
A////.N-   and   atr'nilii*  (all  of  which=mo^nt/S(n«   Dh.)  with  .<?»//>/'/ 
Reeve  adopted  the  name  .s/r/'"/'/.«,  and  figured  the   shell    repi-e-eiited 
by  Sowerby's  fig.  3  of  the  "  Conchological   Illustrations."     This  is 
copied  in  our  fig.  20.     We  are  constrained  by  thetermc  l»y's 

original  description  to  adopt  the  folio  wir  nt. 

Typical  tnlniscus  Sowb.     PI.  38,  fig.  19. 

I'alt;  ashy  olivaceous  green,  streaked  and  mottled  with  black  : 
imdinal  seulpture  all  over  the  mitral  areas,  and  radiating 
sculpture  on  lateral  area.-,  both  .-tr":  loped,  the  latter  a  little 

interrupted  into  regulations. 

The  relations  of  this  form  with  m<nji>  ;ire  inv«  - 


164  <  I II  TON. 

Y;,r.  mesoghjjitns  Pilshry.      PL  38,  figs.  20,  21,  22. 

Olive-brown  or  brown,  unicolored  or  rayed  with  brick  or  blood- 
t he  latter  sometimes  predominating.  Central  areas  having  a 
group  of  longitudinal  striae  on  the  dorsal  ridge,  but  smooth  or  nearly 
so  on  the  pleura.  Smaller  than  the  preceding. 

I  have  seen  a  considerable  number  of  this  form,  which  is  the 
"  var."  described  by  Sowerby  and  figured  in  Conch.  Illustr.,  fig.  41. 
I  am  unable  to  say  whether  it  intergrades  with  the  true  subfuscusor 
not. 

C.  BOWENII  King.     PL  38,  fig.  23. 

Shell  large,  elongated,  elevated,  the  dorsal  ridge  car  in  ated;  red- 
dish-chestnut, olive,  or  ashen  streaked  with  olive.  Mucro  in  front  of 
the  middle,  the  slope  behind  it  straight. 

Central  areas  smooth,  sometimes  with  delicate  longitudinal  strise 
at  the  ridge ;  lateral  areas  elevated,  delicately  radiately  striated,  the 
end  valves  similarly  sculptured.  The  entire  surface  is  microscopic- 
ally granulated  in  quincunx  pattern. 

ln>ide  having  13  slits  in  the  anterior,  1  in  the  central,  17  in  the 
posterior  valve;  teeth  pectinated,  eaves  small;  sinus  wide,  flat,  with 
12-16  teeth. 

Girdle  olive-brown,  in  all  the  varieties  of  valve-coloring ;  scales 
solid,  rounded,  regularly  imbricating,  and  small  for  the  size  of  the 
shell. 

Length  82,  width  38  mill. ;  divergence  98°. 

Length  68,  width  32  mill. 

Strut  ft  of  Magellan. 

Chiton  bowenii  KING,  Zoolog.  Journ.  v,  p.  338  (1831  or  1832).— 
SOWERBY,  Conch.  Illustr.,  f.  37. — REEVE,  Conch.,  Icon.,  t.  2,  f.  9. — 
SMITH,  P.  Z.  S.  1881,  p.  35. — ROCHEBRUNE  &  MAT.II.U:.  Moll.  Cap 
Horn,  p.  141. 

Distinguished  by  its  comparative  smoothness,  unusually  elongated 
form,  and  highly  ridged  back. 

C.  CUMINGI  Frembly.    PL  30,  figs.  29,  30,  31. 

Shell  oval  or  oblong,  elevated,  the  dorsal  ridge  angular,  side- 
slopes  nearly  straight.  Whitish  or  olive,  very  closely  and  regularly 
d  with  brown  or  lead-colored  lines  which  are  concentric  on  the 
end  valves  and  lateral  areas  and  converge  forward  on  the  central. 
areas;  often  blotched  on  some  or  all  of  the  valves  with  lead-brown 
or  buff. 


(  III  1 

Tin1    lateral    an.  parated    from  the   central    area-    l»v    an 

oblique  curved  ridge,  hut  scarcely   raised;  sculptured  with*;  or  7 

low  radiating  riblets,  somewhat  dedicated  by  longitudinal  sub- 
ol)st>lete  riblets.  The  central  aiva<  are  sculptim-d  with  Longitudinal 
rildets  liner  than  those  of  the  lateral  areas.  End  valve.-  having 
radiating  riblets  and  less  distinct  concentric  lira-,  the  iimbo  of  po.— 
terinr  valve  near  the  front  margin. 

Interior  pale  bine  ;  sinus  flat,  toothed;  anterior  valve  having  10, 
central  valves  1,  posterior  valve  l.'J  slit>;  teeth  blunt,  pectinated. 

Girdle  clothed  with  smooth,  convex,  imbricating  scales. 

Length  53,  breadth  34  mill. 

Length  56,  breadth  31  mill. 

Valparaiso,  Chili. 

C.  cumuiynii.  FRKMI'.I.Y,  Zool.  Journ.  iii,  p.  198,  suppl.  pi.  16,  f. 
3. —  C.  cwningsi  DH.  in  Link.,  An.  s.  Vert,  vii,  p.  500. —  C.  cumin '/ii, 
SOWB.,  Conciiol.  Illust.,  f.  32.— REEVE,  Conch.  Icon.,  t.  1,  f.  2. 

This  well-known  species  is  of  a  bronze-olive  color,  closely  lineated 
with  brown  or  olive.  The  lines  are  not  distinctly  -enough  shown  in 
the  figures.  The  range  of  variation  in  contour  and  color-pattern  is 
considerable.  It  has  been  reported  from  the  Cape  Verde  Is.  (Nouv. 
Arch,  du  Mus.  1881,  p.  282),  but  there  cannot  be  much  doubt  that 
the  citation  is  based  on  a  false  locality  label. 


C.  STOKESII  Broderip.     PI.  30,  figs.  25,  26  ;  pi.  32,  figs.  50-53. 

Shell  oval,  moderately  elevated  or  depressed,  the  back  cariuated, 
side-slopes  straight.  Brownish-black,  toward  the  middle  often 
more  or  less  marbled  longitudinally  with  dirty  white. 

Lateral  areas  somewhat  raised,  closely  sculptured  with  radiating, 
irregularly  gntnnlous  and  anastomosing  riblets.  Central  areas 
sculptured  throughout  with  low  close  longitudinal  riblets,  often  made 
slightly  granose  by  the  lines  of  growth.  End  valves  covered  with  a 
net-work  of  nodose  riblets  generally  very  much  interrupted  ;  umbo 
of  posterior  valve  near  the  front  margin. 

Inside  smooth,  varying  from  blue-white  to  light  blue,  the  sutural 
plates  paler,  all  of  the  valves  marked  with  a  spot  of  dull  brown. 
Sinus  deep,  rather  narrow  and  angular,  jaggedly  toothed.  Anterior 
valve  havinir  1<>,  Central  valves  1.  posterior  valve  15-16  slits. 


166  (  HITON. 

( .irdle  (pi.  32,  figs.  53)  covered  with  solid,  convex,  subcarinated 
imbricating  scales.  Length  68,  breadth  f>0  mill. 

Gun?/       .   II  >>•>  Mexico,  to  Panama  and  West  Coliunhin. 

Chiton  stokesii  BROD.,   P.  Z.  S.,   1832,   p.   25.— S,,\vi;..   Conch. 

mufltr., f.  24.— REEVE,  Conch.  Icon.,  1. 1,  f.  4.— M..I:<  H.  Mai.  151. 

vjj    p    171; — Chiiun  jtnttilu*  Sown.,  Charleswortli's  MULT.  Nat.  Ili.-t. 

.  p.  •_".»!  :  Conch.  Illustr.,f.  134.— RKKVE,  Conch.  Icon.,  f.  30.— 

>il,fn.<  CPU.,  J/\ 

The  sculpture  of  the  lateral  areas  is  peculiar,  being  something  like 
the  meshes  of  a  stretched  net,  but  the  cords  or  riblets  are  irregularly 
irranulose.  In  uniting  the  C.  patulus  of  Sowb.  to  stokesii,  I  quite 
agree  with  Carpenter,  who  writes  as  follows:  The  form  patulus  is 
typically  "  engine-turned  "  on  the  terminal  valves,  with  strong  ruga? 
on  the  sides,  and  larger  scales  on  the  girdle.  A  young  specimen 
sent  by  Mr.  Cuming  has  only  18  slits  in  the  tail  plate.  The  typical 
stokesii  has  the  terminal  rugae  radiating,  and  sometimes  a  row  of 
color  tints  at  the  sutures.  The  bulk  of  the  Panama  and  San  Juan 
i  niens  (of  which  I  have  examined  many  hundreds)  are  so 
variously  intermediate  between  the  two  forms  that  I  find  it  impos- 
sible to  separate  them  even  as  varieties.  The  scales  are  extremely 
deciduous,  and  specimens  in  good  condition  are  not  often  found. 
It  was  often  the  custom  of  Mr.  Cuming  to  select  extreme  forms  for 
his  cabinet;  and  these  being  described  and  figured  as  the  normal 
types  of  species  are  very  apt  to  mislead  students  who  work  by  single 
specimens. 

( '.  vi  1:1.1  i.  \  rrs  Sowerby.     PI.  32,  figs.  54,  55,  56. 

Shell  ohlonir,  parallel-sided,  rather  elevated,  the  dorsal  ridire  ear- 
inated,  side-slopes  straight.  Lateral  areas  and  end  valves  olive- 
brown,  or  like  the  central  area<  which  are  green,  longitudinally 
cl..iided  with  blackish  :  girdle  jinn  ami  W/W.  t  ransversely  or  longitu- 
dinally banded. 

The  lateral  areas  are  raised  and  -culptur.-d  with  rwmenut    s-10) 

ifiti'i  rifift.'t-*,  irli ic/i  /mi'  "-//  //,  sji/it  or  branch.       Central 

areas  sculptured  with  longitudinal  rihlets  which  at  the  sides  diverge 

a  little  and  are  nearly  as  coarse   as  those  of  the  lateral  areas,  hut 

finer    and  parallel  to    the    rid^e    toward    the  middle.      Km! 

valves  having  dose  radiating  riblct>  :   ap.  \  of  tail  valve  ante)  i 

In-ide    dark   I>1>  sutural-plates  hi'jh.  blue-irr-  en.     Sinus 

angular  and   tootln-d.      Ant-.i-r   valvi-   liavinjr  '1\-1'1,  <-cnh*<il 


•  ill  ION. 

posterior  valve    I  !i   20    "  i''  •  th    \vid»-, 

blunt,  pectinated  ;  bort,  narrow.  BpODj 

(  ;irdle  compact!;,  I   with    solid,    */*//////;/    convex    scales  (pi, 

82,  li.ir.  •• 

ofena  /.'  ft/omw  ;  ';>///'"/  Calij 

-    WB.  in  Charlesworth's  Mag.  Nat  Hi>t.  1840, 
P.  L'!»I  ;  Conch.  Illustr..  1'.  132.-    REEVE,  Conch.  Icon.,  t.  21,  f.  140. 

Thi>  species  is  allied  to  ('.  N/fi/w//,  hut  differs  in  bring  narrower, 
more  elevated,  dilierently  colored,  in  having  the  riblets  iim-r.  inoj-e 
nunuM-oiis  and  less  anastomosing,  in  the  color  of  the  interior  and  in 
the  iinmher  <>f  .-lius  which  is  much  Lfi'eater  in  the  end  valves  of  this 
species  than  in  those  of  C.  ttnketii,  and  in  some  of  the  intermediate 
valves  there  are  two  slits  in  one  or  both  sides.  The  entire  surface, 
as  usual  in  this  genus,  is  microscopically  granulated.  The  girdle- 
scales  are  liner  and  smoother  than  in  <".  s/o/r*//,  and  the  sutural- 
plates  are  different  in  form. 

A  square  mm.  of  the  girdle  is  shown  by  the  dotted  line  in  fiir.  ~><>. 

It  has  been  reported  from  Australia,  but  erroneously.  Many  spec- 
imens are  before  me  from  the  localities  given  above. 

The  remarkable  feature  of  this  species  is  that  it  forms  a  perfect 
transition  between  the  restricted  genus  Chiton  and  the  section 
/iV/>/</.  Some  specimens  have  two  slits  in  one  end  of  one  valve 
only;  others  have  two  slits  in  the  majority  of  the  valves;  and 
scarcely  two  are  alike  in  the  arrangement  of  1-and  2-slit  insertion- 
plates.  I  have  examined  the  interior  in  about  a  dozen  individuals 
and  have  always  found  at  least  one  insertion-plate  Radsioid,  but 
probably  a  larger  series  would  reveal  specimens  with  the  normal 
plates  of  ( 'lit t<> a  >•.  x. 


C.  GRAN08U8  Frembly.     PI.  30,  figs.  27,  28. 

Shell    oval-oblong,    moderately  elevated,  scarcely    earinated,  the 
side-slop«->  somewhat  convex.     Black,  having  a  white  stripe  <»t  e<icl> 

i  the  central  l'm<\  clouded  with  whitish  between  the  .-tripes. 
Lateral  areas  bearing  three  or/'"/.--  "'</</-///•<  on  a 

ih  ground:  <•,•////••//  iirea*  hnrintj  a  narrow  smooth  dorsal  bandt 
the  sides  (pleura)  covered  "•/'///  dose,  fine  longitudinal  -.vhidi 

are  more  or  less  crenulated  by  the  gn»\\  th-lines.  Knd  valves  hav- 
ing rounded  pustules  in  radiating  rows  or  irreguhirlv  scattered; 
umbo  of  tail  valve  near  the  front  margin. 


CHITON. 

Interior  whitish  clouded  with  olive-plumbeous  posteriorly  and  on 
autural-laminse  ;  sutaral-platee   wide,   sinus  rounded,   toothed: 

lor  valve  having  14-1."),  central  valve-  1  ,  pi.-tennr  valve  15-18 
slits;  teeth  hlnnt,  pectinated:  eaves  short,  .-pongy.  The  sutural 
lami:  .o  »th  in-ide.  the  anterior-median  fni'-t  is  finely  wrinkled 

nor  tract  is  punctate. 

tiirdle  clothed  with  coarse,  angularly-convex,  imbricating  scales. 
Length    Id,  breadth  2i;  mill. 

'//'//'<;/'  /Vm/'/-<,  r«t<nj<>n'nt  ;    V<i/jKir<u#'>,    ('hill. 

1'liiton  fjrano*n*  FKKMKLY,  Zool.  Journ.  iii,  p.  200,  suppl.  pi.  17. 
f.  1  (1827).  —  Dn.  in  Link.,  An.  s.  Vert,  iii,  p.  500.  —  SOWB.,  Conch. 
Illustr.,  p.  2:  Moll.  iBeechey's  Voyage  of  If.  M.  S.  'Blossom,'  t. 
4<>.  f.  .">.  —  IIi:i-:vi:,  Conch.  Icon.,  t.  5,  f.  27.  —  LojJii/rti*  (j,-an».-«i*  TAP. 
<  IAN.  Viag.  '  Magenta'  p.  75. 

The  pustulose  lateral  areas  and  end   valves   and  the  black,  two- 

striped  color-pattern  are  the  stronger  features  of  the  exterior  of  this- 

nid  the  interior  is  no  less  strongly  marked  by   the  trans- 

wrinkling  of  the  front  part  of  each  valve,  which  may  be  readily 

seen  under  the  lens  without  dis-articulating  the  shell.      This  wrink- 

ling in  other  species  is  confined  to  a  band  the  width  of  the  sinus,  and 

is  much  le.-s  strongly  developed.     The  second   valve  is  broad  and 

beaked,  with  only  a  narrow  smooth  dorsal  line  :  the  following  valves 

have  a  distinct  smooth  band. 


(  .  8TR1  vn  N9QUAMO8U8  (  'arpenter. 

Shell  s'ibrotund,  depressed,  pale  brown-olive  ;  entire  suriace  of  the 

valves  densely  granulated  :  lateral  areas  rather  distinct,  valves  wide, 

.-liirhtly     curved,    scarcely     beaked;   jugum    scarcely    distinct,   very 

delicately   longitudinally  striated,  lateral   margins  planate  :   mucro 

iior.  -lightly  distinct. 

Girdle  furnished  with  solid,  oval,  large  hardly  crowded  scale-, 
part  deeply  siriated  :  maririns  <>f  t  he  valves  serrated  ;  median  valves 
with  a  .-ingle  .-lit  on  each  side,  end  valves  having  about  12  slits: 
.-iitnral-plate-  i  '".-ly  arcuate. 

Length  }  .  l.r.-adth  3,  alt.  1  mill.;  divergence  140°.    (Cpr.) 

M'l-'itlnn,  on  Si»nnihjln>-  <•<> 
••/»'/mo.s/'.<  <   i'i:..  (  'at.  Ma/at.  Sh.,  p.  1<I2. 


<    III  l"\. 

•///,  /•;./.>•/  ///.« 
kTiLia  Reeve,     PL  W  I,  84, 

Shell    OVftte,     valvr<    very    e|..<ely    elevately    -iriatrd    t  li  roiiL'hoiit , 

ad  there  inn   rarely,  bifurcately-divergent,  intfi 

rather  exeavated.      \\\  Q,  vell<»\\i.-li  in  the  middle,  \\ith  nar- 

row    transverse    im-en    bands.      Ligament    .~<|iiamately     coriaceous, 

scales  pair  >ea  irreen. 

A  peculiar  smoothly  bronzed  shell,  painted  across  the  middle  with 
narrow  hands  or  ripples  of  green.  (Reeve.) 

•sima}  ./•///'///. 

C.  aqiidtilis  REEVE,  Conch.  Icon.,  f.  7-'5. 

Reeve  gives  no  locality  for  this  species.  The  figures  on  my 
plate  are  copies  of  his. 

Carpenter  writes  as  follows  of  Reeve's  type  specimen  :  One  spec- 
imen made  up  of  two,  only  the  valves  stuck  together.  I  counted 
just  eleven  scales  in  one  corner,  though  Reeve  describes  and  figures 
it  as  complete.  The  very  insertion-plates  are  in  great  measure 
rubhed  off.  It  may  equal  my  C.  densiliratus  in  poor  condition. 
Anterior  valve  having  10,  central  valves  1,  posterior  valve  1:5  slits ; 
teeth  pectinated  ;  eaves  short.  Shell  rather  elevated,  the  dorsal 
ridge  sharpish.  Central  areas  with  extremely  close  fine  parallel 
striae,  jugal  area  not  defined.  Lateral  areas  not  elevated,  having 
1  ^  radiating  lines,  extremely  close  and  fine,  as  on  central  areas,  but 
rather  more  developed  ;  the  end  valves  similarly  sculptured,  mucro 
in  front  of  the  middle;  posterior  slope  very  concave.  Marked 
"?  Japan";  and  the  habitat  of  a  specimen  sent  by  Damon  for  pur- 
chase is  Tsu-Hina,  Japan.  The  valves  alone,  without  -'irdle,  and 
irregularly  placed  measure: 

Length  40,  breadth  23  mill.;  divergence  !<).">  . 

C.  PKNsiuuATrs  Carpenter,  n.  sp. 

Shell  oval,  solid,  elevated,  the  jiiu'iim  acute  :  mucro  scarcely 
prominent,  subantcrior.  Ashy  or  pale  bmwii,  irregularly  clouded 
with  chestnut  or  black,  often  eleirantly  dotted  with  darker  or  paler. 

Central  areas  having  about  *2~>  rildet<  on   each  side  of  the  juurum 
and  parallel  with  it,  obsolete  at  the  rid;re:   lateral  area-  well  defined, 
having  S-10  line,   sometimes  bifurcating;   end  valve<  having  *: 
such  line. 


170  CHITON. 

Inside:  anterior  valve  having  8  ;  central  ralvefl  i.  posterior 
valve  18  slits;  teeth  normal,  very  closely  pectinated ;  sinus  narrow, 
havinir  about  1 1!  minute  denticles. 

idle  unicolored  or  tessellated,  bearing  normal  imbricating  scales 
which  here  and  there  are  very  minutely  Mriatulate. 

Length  :>s,  width  33  mill.;  divergence  110°. 

,I<i}»in  (Mus.  Cum.,  no.  16.) 

This  species,  says  Carpenter,  from  whose  J/N.  the  above  descrip- 
tion is  taken,  is  easily  recognized  by  the  very  close  ribs,  arranged  like 
miniature  whale  bone. 

C.  MARQUESANUS  Pilsbry,  n.  sp.     PI.  36,  figs.  98,  99,  100. 

Shell  oval-oblong,  depressed,  obtusely  carinated.  the  side-slopes 
nearly  straight.  Surface  smooth  and  polished  on  the  central,  granose 
find  Itisterless  on  the  lateral  areas.  Color  dark  olive-green,  almost 
black  on  the  lateral  areas  and  end  valves. 

Lateral  areas  but  slightly  raised,  sculptured  with  about  seven 
uneven  and  unequal  rows  of  separated  low  warts,  and  under  a  lens 
seen  to  be  covered  with  a  minute  granulation  ;  central  areas  shining, 
having  a  few  low  growth-wrinkles  and  covered  with  a  partly  effaced 
microscopic  granulation.  End  valves  closely  granose  in  indistinctly 
radiating  pattern;  mucro  near  the  front  margin  of  the  tail  valve. 

Interior  light  blue,  stained  at  sinus  and  under  the  beaks  with 
purple-brown  ;  sinus  rather  shallow  and  toothed.  Anterior  valve 
having  21,  central  valves  1,  posterior  valve  25  slits. 

i. lie  dark  green,  covered  with   convex   scales,   which   in  the 
middle  of  its  breadth  are  larger  and  carinated. 

Length  46,  breadth  26  mill. 

M.ti'tjiir.nta  Is.  (Garrett.) 

The  papillose  lateral  areas,  smooth  central  areas  and  uniform  dark 
olive-green  color  are  the  more  striking  features  of  this  species.  The 
large  number  of  slits  is  also  noteworthy.  The  specimen  before  me 
was  presented  to  the  Academy  by  the  late  Andrew  (ianett,  and  it 
was  labelled  "  C.  marqnesann ;  "  but  whether  thi>  name  was  given  by 
Garrett  or  by  Tryon  I  do  not  know. 

C.  PBBVIKIDIS  Carpenter. 

Shell  small,  narrow,  elevated,  thejuirum  acute:  color  an  im 
green.     Entire  surface  very   minutely  scaly   under  a   lens:  lateral 
areas  and  cud   valves   radially    I  irate,  tin-   line  obtuse,  little   con- 
spicuous, 4  or  ~)  on  side-areas,  2"-L'">  <>n  end  val\          '       iral  areas 


(Ill  :  171 

having  about   1  '_'  little  impressed,  di>lant  siilci,  parallel  to  tin-  <i 

Mucro  anteriorouboentral,  moderately  pi  p 

having  *-'•>  slits   in   end   valve-,    I    in    median    valves;   leetli    a 
deeply    peetinated  -hurt;  .-inns   wide,    Mat,  toothed.       (Jirdlc 

furnished  \vitli  large,  solid,  imbricating  but  Mriated  Males. 
Length  Hi,  wi.lt  h  6$,  alt.  .°»  mill. 

TaM 

C/ilfnn  (  Loj,hi/rii.^  itt'i-viridi*  CIM:.,  I*.  /.  S.  1M'>.~>.  p.  511.  L»/>li'j- 
ri(.-i  ptrviridit  PEASE,  Amer.  Journ.  Conch,  vii,  p.  I'M. 

A  solitary  s])ecimen  of  this  interesting  species  is  very  like  (  '.  v!re«- 
Kve.  in  general  appearance:  but  the  mantle  of  tiiat  species  is 
nearly  smooth  and  the  valves  scarcely  sculptured.  This  shell 
a  uniform  bright  green.  It  has  the  aspect  of  Le]n'dltj,/n.nru.<  |  Lepid- 
ozona]  ;  but  the  insertion-plates  though  sharp,  are  deeply  pectinated. 
It  differs  from  most  other  Chitons  in  having  the  scales  di>tinctly 
striated,  as  in  C.  8friato«f]uamosus.  (Cpr.) 

C.  P.URMANUS  Carpenter,  n.  sp. 

Shell  elevated,  with  acute  dorsal  ridge  ;  olivaceous  or  red,  Imciny 
a  white  blotch  <»i  the  tail  vahe  behind  the  mncro. 

Whole  surface  of  the  valves  finely   quincuncially   granulated  ; 
central  areas  havinir  nlmut  '20  .<har}t  mid  distinct  rib*   <>n  c<«-I> 
parallel  to  the  dorsal  ridge,  upon  which  they  are  finer  and  cl 
lateral  areas  having  3  to  5  roiv*  of  stout  granules,  some  of  the  rows 
not  reaching  to  the  apex.     Knd  valves  having  -'">  (or  fewer)  rows  of 
stout  granules.     Mucro  of  the  tail  valve  median,  the  slope  behind  if 
very  concave. 

Interior  having  8  slits  in  the  anterior,  1  in  the  median,  1  1  in  the 
posterior  valve;  teeth  sharp  but  distinctly  pectinated  :  »  aves  -hurt. 

Girdle  covered  with  rather  roundish  oval  scale.-  of  larue  >i/e. 

Length  19,  breadth  l<).l  mill.;  divergence  %°. 

<  'u'i*f  nj  AfiL-'i/i.  />Y///V/  Jtui'inuh,  under  st«»m-s  at  lu\v  water. 

The  British  Museum  contains  four  sj)ecimens,  of  which  three  are 
olivaceous,  the  other  red.  The  above  description  is  from  (  ar- 
penler's  .1/N. 


//'/,  JNV?r  Zt'itliDnl. 

The  S])ecies  of  tli  re  mostly  of  moderate  or  small  - 

and  generally  the  muem   is  central    and    the  scale-  mieroscopicallv 

striated. 


1,1'  CHITON. 

C.  QUO  vi  i  I.    PI.  37,  figs.  6,  7,  8. 

Shell  oval,  rather  elevated.  carinated,  the  side-slopes  straight. 
Surfac.-  having  a  smooth  and  polished  appearance  luit  very  finely 
striated.  ('»!»,•  generally  a  veni  '/a/7;  olive-green,  hut  sometimes 
yelli)\vish  brown  marked  with  olive  on  the  sides  and  ends,  or  clear 
yellow  with  rays  of  olive  or  brown. 

Lateral  areas  slightly  raised,  sculptured  with  numerous  narrow, 
delicate  and  slightly  erenulated  radiating  threads.  Central  anas 
covered  with  still  finer  longitudinal  striae.  End  valves  sculptured 
like  the  lateral  areas,  the  two  about  equal  in  si/e ;  ninero  of  the 
rather  raised  tail  valve  a  little  in  front  of  the  middle. 

Interior  sky-blue,  marked  under  the  beaks  with  olive-brown  rays. 
Sinus  rather  square,  finely  denticulate.  Anterior  valve  having  9- 
10,  central  1,  posterior  13-14  slits;  teeth  erenulated  outside. 

Girdle  covered  with  smooth  convex  imbricating  scales,  mostly 
li.irht  blue,  but  often  having  dark  brown  scales  mingled  with  them. 

Length  37,  breadth  22  mill. 

.1  iK-klnml  to  Dunedin,  New  Zealand,  in  pools  under  stones,  between 

ti«les. 

Chiton  rirnHs  Q.  &  G.,  Voy.  Astrol.  iii,  p.  38^.,  t.  74,  f.  23-28 
(1834).  Not  Chiton  e.rtn*  r/Y/<//>-,  hifn*  c" >/'//'///*  of  Chemnitz,  Con- 
chyl.  Cab,  viii,  p.  i>77,  t.  94,  f.  794,  795  (1785),  nor  t'A.  viridit 
Sprn.irler,  if.  r. —  C/'itnn  (jnoyi  DESH.  in  Lam.,  Anim.  s.  Vert,  vii,  p. 
.  1836).— Ki.i:\  i,  Conch.  Icon.,  t.  13,  f.  68  (1847).—  Chiton 
glawsu*  HITK.N,  Man.  N.  Z.  Moll.,  p.  112  (1880.) 

?  C/tifon  (/fa urn*  GRAY,  Spicilegia  Zoologica  j)t.  i,  p.  5  (1828). — 
':  /.--//A >/ /•//*  r/l<mni8  ANGAS,  P.  Z.  S.  1867,  p.  '2'2'2. 

This  species  differs  from  all  other  true  Chitons  of  New  Zealand  in 
its  finely  sculptured,  comparatively  smooth  surface,  resembling  in 
this  respect  the  t '.  magnificat  of  South  America.  It  is  a  well  known 
New  Zealand  form,  and  has  also  been  reported  fr-nn  Port  -Jack.-oii, 
Australia,  by  . \ii-a-,  under  the  name  £/«"<•">•;  but  I  have  not  been 
able  to  confirm  this  by  the  compari-on  nf  -pecimens  from  the  latter 
locality,  which  may  safely  l>e  omitted  until  authoritatively  con- 
firmed. 

The  locality  of  Gray's  ('.  ylnim.*  was  unknown,  he  did  not  figure 
hi-  -pccimen,  which  had  lost  its  girdle,  and  lie  states  that  it  was 

whit.-  in-ide.  -Ian-  outaide,    The  identification  ofQaoy  and 

(iai  II  d.  -cril.ed  aiid  fi^ureil  shells  from  New  /.'aland  with 


«  III  :  17-". 


<ir;i\  UB  therefore  highly  hypothetical;  rsp»-ri:illy  -in- 

..in-  leemfl  l«>  have  seen  Cray's  type,    and    its  ijrnrrir   eharaeters,  are 
wholly  unknown.        I  hav«-  never  leeo  a  "gb|UCUI  linen 

of  this  species  "wluteioside;"  they  arc  always  blue.     The  cbi 

of  name    made    l>y    Deshayes    must    be  adopted    on    account   oi 
earlier  ('.  riri'H*  of  Spender. 


('.  PELLI88ERPENTIB  <,)iioy  &  Gaimard.     PI.  37,  figs.  14,  15,  16,  17, 

18. 

Shell  oval,  rather  elevated,  hardly  cari nated,  the  side-slopes  some- 
what convex.  Surface  lusterless.  Color  a  rather  dull  and  din-y 
olive  or  olive-green  marked  with  black  along  the  ridge  and  on  the 
sides  of  some  valves. 

The  lateral  areas  are  moderately  raised  and  sculptured  with  3  or 
4  roir*  of  Distinct  tubercle*.  Central  areas  having  *tron</,  irregular 
(jn>irf/i  irrinklc*,  <unl  fine  longitudinal riblets.  Anterior  valve  larger 
and  much  more  elevated  than  the  posterior,  both  being  sculptured 
with  numerous  regular  rows  of  distinct  tubercles,  the  rows  increasing 
by  splitting.  Posterior  valve  depressed,  the  low  mucro  in  front 
of  the  middle. 

Inside  blue,  indistinctly  blotched  with  olive-green.  Sutural- 
plates  rounded,  the  sinus  broad  and  deep,  smooth  or  hardly  dentic- 
ulate. Anterior  valve  having  12,  central  valves  1,  postejpor  valve 
12  slits ;  teeth  blunt,  pectinated.  Eaves  broad. 

Girdle  wide,  alternately  light  and  dark;  scales  (pi.  37,  fig.  17) 
rather  large  and  wide,  often  showing  a  slight  tendency  to  carination 
in  the  middle,  microscopically  striated. 

Length  30,  breadth  23  mill. 

Heiv  Zealand. 

Chiton pelliserpentiH  Q.  &  G.,  Voy.  de  P Astrolabe,  Zool.  iii,  Moll., 
p.  381,  t.  74,  f.  17-22  (1834).— DESK.,  in  Lam.,  An.  s.  Vert,  vii,  p. 
508  (1836).—  Chiton  j>elli*-«erpenti«  KEKVI:,  Conch.  Icon.,  t.  15,  f! 
84.— HUTTON,  Cat,  Mar.  Moll.  N.  Z.  1873,  p.  4C  :  Man.  N.  /,  Moll. 
1880,  p.  111.— HADDON,  Challenger  Polyplac.,  p.  '2'2. 

This  is  one  of  the  most  abundant  New  Zealand  Chitons.  Its 
sculpture  is  frequently  obscured  or  lost  by  erosion.  C.  sim'/nirl  is 
closely  allied,  but  it  differs  in  color-pattern,  in  the  poll." licit  central 
areas,  whilst  the  surface  of  pelli«-*erpenfis  is  lusterless,  and  in  the 
sculpture  of  the  central  areas.  The  median  valves  of  pellisserpenti* 


174  i  HITON. 

are  rather  stronirlv  arrhed  hack  ward,  and  the  broad  sinus  is  remark- 
able for  the  absence  or  obsolescence  of  teeth.  The  interior,  except 
just  behind  the  .-inns,  is  smooth  ;  the  callus  in  each  valve  is  heavy 
and  smooth.  Figures  14,  !•>,  17  arc  drawn  from  Auckland,  X.  /. 
examples,  furnished  by  Mr.  <  J.  W.  Wright. 

C.  SINCLAIRI  Gray.    PI.  36,  figs.  1,  2,  3. 

Shell  oval,  rather  elevated,  the  dor*«l  ridge  rounded,  side-slopes 
rather  straight;  brown-black,  each  valve  irregularly  and  raggedly 
Hh  whiti*h;  the  head  valve  pale  with  dark  rays.      Some- 
times the  white  predominates. 

The  lateral  areas  are  raised  and  sculptured  with  three  or  four 
i-'id  luting  grano«e  rib*,  often  *nbobsolete.  Central  areas  xmooth  in  the 
middle  except  for  a  few  growth-wrinkle*,  but  having  fine  .«hort  lougitu- 
•<>  the  ."life."  in  front  of  the  diagonal  line.  These  riblets 
are  sometimes  almost  obsolete.  Head-valve  sculptured  at  first  with 
about  15-18  granose  riblets,  but  as  these  have  a  tendency  to  split  as 
the  valve  grows,  the  number  in  a  grown  specimen  is  usually  24-30. 
Tail-valve  having  a  low,  obtuse  mucro,  decidedly  in  front  of  the 
middle. 

Interior  bluish.     Sinus  rather  wide,  denticulate,  the  area  behind 
it  porous.      Anterior  valve  having  11,  central  valves  1,  posterior 
valve    14  slits;  teeth  obtuse,  strongly  crenulated.      Eaves   broad, 
_y. 

Girdle  (pi.  36,  fig.  3)  covered  with  large,  convex  scales,  which 
are  very  finely,  sharply  striated. 

Length  28,  breadth  18  mill. 

Length  17,  breadth  11  mill. 

New  Zealand  (Sinclair,  Hutton,  Wright.) 

Chit"n  ."'nn-lnu'i  ClHAY,  in  Dieftenbach's  Travels  in  N.  /.  ii,  p.  263 
(1843).— HUTTON,  Trans.  N.  Z.  Inst.  iv,  p.  177  ;  Man.  X.  /.  Moll. 
p.  Ill  n«.sO).— SMITH,  Zool.  '  Erebus'  and  'Terror,'  p.  4.  t,  1,  f. 
17.— REI-:VE,  Conch.  Icon.,  t.  22,  f.  143. 

The   smooth,    polished    central  areas,   grooved    only    al..ii'j     the 

•  nal  line  at  t  he  sides,  and  the  granoa6»lii>bed    lateral   area<  and 

en  1  valves  are  characteristic,  and  remind  one  of  the  \Ye.-t  Indian  ( '. 

The  black-and-white  coloring  also  is  rather  constant.     The 

ivas  varies  greatly   in  stn-n^th.     This  s-pecies 
has  been  reported  from  Tasmania,  but  mi  doubtful  authority. 


'  III 
( '.  i  Souverbie,     I'l.  <'»">.  il^.  •'!,  4. 

Shell    ovate-ohlonir,    the    hack    earinatt-d,    nmhoiMS    HihroMi 

-ii  «.r  yrllowish-ivd,  with  lon<rit udina I  more  or  ]e.~s  pallid 
and  more  or  less  numerous  spots.  Knd  vnlvt-s  oi •namentcd  with 
ahoiit  L'H  radiatin.  luhercles  (some  of  tli< 

being  shorty  intercalated  between  the  other-);  lateral  areas  having 
three  scries  of  tuherdes  and  a  fourth  intercalated  shorter  series. 
Central  areas  sculptured  on  each  side  of  the  smooth  dorsal  carina 
with  impressed,  suhohliquely  longitudinal  grooves.  Girdle  leathery 
and  scaly.  Dimensions,  exclusive  of  the  girdle,  which  is  very  incom- 
plete in  our  two  examples  (probably  immature)  ;  length  19,  breadth 
mill.  (6W.) 

Art  J*/nnd,  N.  Caledonian  Archipelago  (Mus.  Bordeaux.) 

Chiton  decolor  Souv.,  Journ.  de  Conch.  1866,  p.  252,  t.  9,  f.  1,  la. 
—  C.  miniacens  CPU.,  J/\,  Mus.  Cuming. 

Carpenter's  unpublished  species  seems  to  be  the  same  as  this, 
although  until  the  types  of  discolor  are  examined,  we  cannot  be 
certain.  Carpenter's  description  here  follows: 

C.  miniacen*  Cpr.  Shell  elevated",  oval,  the  jugum  acute ;  vivid 
vermilion,  the  margin  tessellated  with  paler.  Mucro  median,  little 
el'-vated.  Entire  surface  minutely  punctate;  central  areas  having 
about  25  subparallel  grooves  on  each  side,  obsolete  on  the  dorsal 
ridge ;  lateral  areas  elevated,  bearing  3-4  strong,  radiating  line, 
which  are  strongly  nodose.  End  valves  having  about  20  line. 
Interior:  anterior  valve  having  8,  central  1,  posterior  10  slits;  teeth 
deeply  pectinated;  sinus  wide,  minutely  denticulated.  Girdle 
covered  with  normal  imbricating  scales. 

Length  27-1,  breadth  20  mill.;  divergence  100°. 

New  Caledonia. 

MILS.  Cum.,  no.  59.  Easily  recognized  by  the  strong  sculpture 
and  brilliant  vermilion  color.  (Q>r.) 

(  .  MTRICATUS  A.  Adams.     PI.  37,  figs.  12,  13. 

Shell  oblonir,  much  elevated  in  the  middle;  black-brown  and 
white  variegated.  Knd  valves  and  /titrml  urem*  n/'/m/r///  i-illictl, 
the  ribi  Ornamented  n'if/i  dcmlcd  acute  f/niinn:  tail  valve  umbon- 
ated  in  the  middle.  Central  areas  longitudinally  deeply  lirate,  the 
umhoiics  smooth,  elevated,  somewhat  produced.  (Jirdle  scaly,  the 
scales  mucronatcd,  imbricating,  with  subenrt  apices. 


1  ,  t ;  ,in 

Tliis  species  is  remarkable  for  the  somewhat  triangular  imbricate 
BOalefl  of  the  ligament  ending  In  slmrp  i«>iutc<l  nmcmnes;  the  liga- 
ment is  tessellated  with  pale  fuscous  and  dark  brown  ;  the  ribs  on 
the  lateral  areas  are  four,  inurieated  with  sharp  granules.  (Ad.} 

Sy<li-:.  V.  N.  W<tlest  Australia,  under  Btonea  at  low  water. 
(Strange.) 

Ctntnn  »  A.  AD.,  P.  Z.  S.  1852,  p.  91,  t.  16,  f.  Q.—Lophy- 

nis  MurtMtua  AN..AS,  1>.  /.  S.  1865,  p.  186;  1867,  p.  222.—  Clnt»n 
/ini'ins  and  C.  carn»*n*  CIM:.,  J/.s'N. 

Varies  in  color  from  dull  green  to  orange  and  bull'. 

Carpenter  examined  Adam's  type  of  this  species,  and  ascertained 
it  to  be  identical  with  his  own  unpublished  (.'.  li»i<tiis;  the  descrip- 
tion of  which  here  follows: 

Shell  oval,  elevated,  the  jugurn  acute;  mucro  median,  subprom- 
inent ;  olivaceous,  maculated  with  paler ;  entire  surface  minutely 
punctate;  central  areas  having  about  14  grooves  on  each  side, 
obsolete  in  the  middle;  lateral  areas  having  two  riblets,  sometimes 
bifurcating  or  with  another  intercalated,  furnished  with  strong  acute 
tubercles,  interstices  smooth ;  end  valves  with  10-20  such  riblets. 
Interior  :  anterior  valve  having  8,  central  1,  posterior  valve  9  slits; 
teeth  normal ;  sinus  moderate,  with  about  15  denticles.  Girdle 
furnished  with  large  and  small  wide,  distinctly  striated,  elevated, 
acutely  pointed  scales.  . 

Length  23],  breadth  12*,  divergence  100°. 

The  points  of  the  striated  scales  project,  as  in  Isc/i.  australis,  so  as 
to  give  the  girdle  a  rasp-like  appearance. 

Yar.  nurnntlns  Cpr.  Shell  smaller,  pale  orange  colored,  dotted 
with  more  intense;  posterior  valve  with  10  slits. 

Length  17*,  breadth  10  mill.;  divergence  100°. 

Like  the  preceding  in  all  important  character?,  but  differing 
remarkably  in  color  and  pattern. 

A  form  in  which  the  sculpture  of  the  side  areas  is  less  developed 
received  the  name  carnosns  ( 'pr.  The  original  description  in  Carp- 
enter'- .1/v  !>efore  me,  indicates  the  following  as  the  m<»t  important 
characters  of  cnrnosmt :  Central  areas  having  about  18  suhparallel 
-ulci  on  each  side,  more  prominent  toward  the  margin,  obsolete 
toward  the  jugnm  ;  lateral  areas  and  end  valves  having  irregularly 
(at  the  sutures  strongly)  nod.»e  wrinkles,  4  in  number  on  the  >ide 
areas,  22  on  the  anterior,  14  on  the  posterior  valve, 


i  111  1.7 

hi  fin-cat  iii'j:.       Interior:    anterior    valve    with*,   central   1,    post 

valve-  LOsliti,     Length  80,  breadth  ir>  mill.;  divergence  l< 

Ka-ily  rec«»_i:ni/ed  by  the  ilesliy   color  and  small,   beaked,   ma: 

scales;  the  side  sculpture  of /imotw  (with  which  this  species  agrees 
in  the  scales)  11  very  diflerent  in  pattern.     (Cpr.) 


(\  c  \\\\.\<-(  \.\v\  >  (^imviV  <iaimard.      1M.  .'Hi,  li.urs.  4,  5,  6. 

Shell    small,  ohloni:,  N//V///J////  elevated,  carinated,  the  side-si* 
straight,  steep.     End   valves  and   lateral  areas  pink,  central   areas 
yellowish .  dorsal  ridge  pink  with  an  olive-green  stripe  on  each  side. 
Sometimes  olivaceous,  or  olive  and  rose. 

The  lateral  areas  are  strongly  raised  and  sculptured  with  4  or  ."> 
radiating  ribs  which  are  regularly  cut  into  low  beads,  and  which 
often  split  toward  the  lower  margin.  Central  areas  having  a  narrow 
smooth  space  upon  the  ridge,  sculptured  on  each  side  with  about  16 
strong  longitudinal  ribs,  separated  by  deep  intervals ;  posterior  mar- 
gins of  valves  crenulated.  Anterior  valve  having  about  22  granose 
radiating  ribs  ;  posterior  valve  having  about  16  granose  radiating 
ribs,  the  umbo  slightly  in  front  of  the  middle,  the  slope  behind  it  a 
little  concave.  Interior  whitish;  sinus  rather  deep  and  narrow. 

Girdle  covered  with  compactly  imbricating,  convex,  shining  obso- 
letely  striated  small  scales  (pi.  36,  fig.  6.) 

Length  14,  breadth  11  mill. 

Ta*man  Bay's  (Q.  &  G.),  and  Stewart  Island  (Hutton),  Xew  Zea- 
land. 

Chiton  canalicnlatus  Q.  &  G.,  Voy.  Astrol.  Zool.  iii,  p.  394,  atlas, 
t.  75,  f.  37-42  (1834).—  Chiton  stangeri  REEVE,  Conch.  Icon.,  t.  22, 
f.  150  (1847).—  Chiton  insculptus  A.  ADAMS,  P.  Z.  S.  1852,  p.  91,  t. 
16,  f.  4.— ef.  HUTTON,  Man.  N.  Z.  Moll.  1880,  p.  Ill,  112. 

Allied,  in  its  acutely  elevated  contour,  to  C.,/".'/"*"^,  but  differing 
maikedly  in  the  granose-ribbed  lateral  areas.  It  is  usually  very 
brilliantly  colored  with  rose-pink  and  buff)  but  olivaceous  torn  i- 
occur.  The  latter  may  be  distinguished  from  C.  *uit'lairi  by  the 
differently  sculptured  central  areas.  Professor  Hutton  (in  lift.) 
suggests  to  me  the  identity  of  stangcri  and  inm'iiljtt'i*.  The  latter 
seems  to  agree  altogether  with  (Buoy's  oanaKcMlatut. 

The  girdle-scales  (pi.  36,  fig.  6)  are  smaller  than  in   ('.  jiignsus, 
and  they  are  much  less  distinctly  striated  than  in  ('.  ,s///" 
pettiuerpentis. 


178  (   II1TON. 

( '.  .injosus  Gould.     PI.  36,  figs.  91,  92,  93,  94,  95. 

Shell  oblong,  much  elevated,  carinated,  the  side-slopes  straight 
and  steep.  Central  areas  sulcate  at  the  sides,  smoufli  in  the  middle, 
literal  urea*  smooth.  Color  light  green,  the  ribs  of  the  central  < 

>/e,  lateral  areas  with  fine  alternating  concentric  lines  of  yellow 
and  green. 

The  lateral  areas  are  strongly  raised  and  smooth,  painted  with 
close  lines  parallel  to  the  dorsal  keel.  Central  areas  having  a  smooth 
triangle  in  the  middle,  the  sides  sculptured  with  11-14  strong 
rounded  orange  colored  ribs,  separated  by  deep,  blue  intervals  of 
the  same  width.  Head  valve  smooth,  concentrically  lineated  ;  tail 
valve  concentrically  lined  at  the  sides,  having  a  broad  triangular 
buff  or  orange  ray  behind,  extending  across  the  girdle  ;  apex  project- 
ing slight  li/  behind  the  middle,  posterior  slope  strongly  concave. 

Interior  blue-white,  the  sutural  plates  white.  Sinus  narrow  and 
angular,  denticulate.  Anterior  valve  having  8,  central  valves  1, 
posterior  valve  12  slits ;  teeth  blunt,  pectinated.  Eaves  spongy. 

Girdle  (fig.  95)  buff  and  greenish,  irregularly  alternating,  covered 
with  compactly  imbricating,  polished  convex  scales,  which  are  obso- 
letely  striated.  Length  35,  breadth  20  mill. 

Port  Jackson,  Sydney,  N.  S.  Wales,  Australia. 

Chiton  jagosus  GOULD,  Proc.  Bost.  Soc.  N.  H.  ii,  p.  142  (1846); 
Expl.  Exped.  xii,  Moll.  &  Sh.,  p.  317,  atlas,  t.  28,  f.  430  (1852).— 
SMI  in,  Xool.  Coll.  H.  M.  S.  'Alert/ .p.  78  (1884).— HADDON,  Chall. 
I'olyplac.,  p.  22  (1886).— Lop hyr us  jugosus  GLD.,  Otia,  p.  3,  242 
(1862).— ANGAS,  P.  Z.  S.  Lond.  1867,  p.  222.—  C/nton  concsntricns 
Ki  i:vi:,  Conch.  Icon.,  t.  16,  f.  95  (1847). — Lophyrus  concentricus 
ANGAS,  P.  Z.  S.  1867,  p.  221. 

The  peculiar  and  beautiful  coloration  separates  this  species  from 
its  allies.  The  second  valve  is  frequently  blood  red,  or  blotched  at 
the  sides  with  dark  sepia;  and  occasionally  all  or  many  of  the  valves 
have  blotches  of  buff  interrupting  the  longitudinal  color-lines.  The 
light  triangle  radiating  backward  from  the-  uinho  of  the  tail  valve  is 
present  in  every  specimen  I  have  seen.  The  tail  valve,  indeed, 
i «  in  Sin  Is  one  somewhat  of  that  of  an  irregular  Chiton. 

Tin-  paintiiiLT  of  tin-  lateral  areas  gives  the  impression  that  they 
are  longitudinally  ribbed,  as  Reeve  and  An.iras  havr  dcscrilx-d  :  but 
even  in  Reeve's  tyj>e8  these  areas  are  quite  .-month,  as  they  are  in  all 
the  specimens  I  have  seen. 


179 

This  sp.-eie-  has  hem  reported    from    New  Zealand,  hut    probably 

incorrectly, 

('.  ITI.VIN  \  rrs  ( 'arpenter,  n.  sp. 

Shell  small,  oval,  suhelevated,  with  acute  jiiiruni  :   IMIHTO  median  ; 

apie»-s  ot'  the   valves   prominent;  olivaceous  and    !>ro\vn    variously 

clouded  and  irregularly    painted.      Kntire  surface  minutely  punet- 

ulated  ;  mitral  areas  hari n</  <t/>out.l6  deep  su lei  on  each  side;  lateral 

«','//  (lejiiH'd,  H en rh/  smooth,  as  are  the  end  valves  also. 

Interior:  anterior  valve  having  10,  central  valves  1,  posterior 
valve  !>  slits;  teeth  acute,  deeply  serrated  ;  sinus  moderate,  dentic- 
ulate. 

( Jirdle  covered  with  large  smooth  scales. 

Length  0,  width  4*  mill.;  divergence  110°.     (Cpr.) 

New  Ireland  (Mus.  Cuming,  no.  78.) 

Distinguished  from  Inzonicus  by  the  smooth  scales  and  side-areas, 
which  display  a  velvety  appearance  under  the  microscope. 


C.  yEREtis  Reeve.     PL  36,  figs.  96,  97. 

Shell  oblong-ovate,  angularly  raised  in  the  middle ;  valves  rudely 
impressly  striated  throughout,  umbonal  eminence  smooth.  Dull 
green  ;  ligament  granosely  coriaceous. 

The  color  is  a  uniform  dull  green  except  along  the  rubbed 
umbonal  summit,  where  it  has  a  copperas  hue.  (Rve'} 

New  Zealand  (Earl.) 

Chiton  cereits  REEVE,  Conch.  Icon.,  t.  7,  f.  36  (1847). —  Chiton 
(Leptochiton)  cerens  SMITH,  Zool.  Voy.  '  Erebus  '  and  '  Terror '  Moll, 
p.  4,  t.  1,  f.  9.—  CA.  siculoides  CPR.,  MS. 

This  species  has  been  referred  by  Smith  to  C.  siculus  Gray.  The 
locality  requires  confirmation,  as  it  rests  solely  upon  Cumingian 
specimens.  Hutton  (Man.  >.'.  7.  Moll.)  reprints  Reeve's  diagnosis 
without  comment. 

Carpenter's  notes  on  Reeve's  type  are  as  follows ;  Central  areas 
having  about  20  furrows  on  each  side,  not  deep,  continuing  until 
they  are  rubbed  off  in  the  middle;  lateral  areas  having  4-8  divari- 
cating riblets,  much  worn,  broken  up  by  the  concentric  ruga  of 
growth;  crenate  at  the  sutures;  end  valves  with  about  30  riblets. 
Mucro  in  front  of  the  middle,  posterior  slope  concave.  Interior 


180  <  I II  TON. 

bluish,  sinus  with  ~>-13  denticles,  deep,  narrow;  girdle  scales  stout, 
roundish.     Length  :J!»,  breadth  23,  divergence  94°. 

One  specimen,  New  Zen  land,  in  Mus.  Cuining. 

Species  of  the  Mediterranean  and  African  Seas. 

The  species  are  allied  to  those  of  Australia  and  New  /ealuml,  the 
iiiucro  in  many  of  them  being  central,  and  the  scales  striated. 

C.  OLIVACEUS  Spengler.    PL  35,  figs.  87,  88,  89,  90,  91,  92. 

Shell  oblong,  elevated,  carinated,  the  side-slopes  strain  lit.  Surface 
ribbed  and  microscopically  punctulate.  Color  very  variable ;  either 
black,  brown,  scarlet  or  olive-green,  unicolored  or  clouded  or 
mottled. 

Lateral  areas  raised,  sculptured  with  4-6  flat  Ion-  rndi'tfi:ii/  ribs, 
the  posterior  rib  widest,  separated  by  narrow  shallow  grooves. 
Central  areas  having  a  smooth  triangle  on  the  ridge  of  each  valve,  the 
sides  (pleura)  bearing  strong  longitudinal  ribs,  which  become 
stronger  toward  the  outer  margin.  End  valves  having  low  radiating 
riblets.  Tail  valve  having  a  conspicuous  central  apex,  the  posterior 
slope  somewhat  concave. 

Interior  light  bluish,  marked  with  brown  rays  in  each  valve. 
Sutural  plates  rounded  ;  sinus  deep,  square,  denticulate.  Anterior 
valve  having  7-8,  central  valves  1,  posterior  valve  8-10  slits ; 
teeth  blunt,  pectinated.  Eaves  spongy.  Girdle  wide,  banded  with 
alternate  light  and  dark,  compactly  covered  with  minute  smooth, 
convex  scales.  Length  36,  breadth  20  mill.,  often  less. 

Mediterranean  and  Adriatic  Seas ;  Cape  Verde  Is. 

Chiton  squamosus  POLI,  Test.  utr.  Sicil.  i,  t,  3,  f.  21,  22  (171)1) 
and  of  PAYRAUDEAU,  COSTA,  and  PHIL.,  Enum.  Moll.  Sicil.  i,  p. 
106,  t.  7,  f.  3;  and  of  Granger,  Moll.  France,  p.  170,  t.  12,  f.  16 
(1885).  Not  of  Linne*. —  Chiton  olivaceus  Sn:v.i.r.K.  Skrivter  af 
Naturhistorie-Selskabet,  iv,  p.  75,  t.  6,  f.  8a-c  (1797).— Jeffreys,  Rep. 
Asso.  Adv.  Sci.  1873,  p.  113. — MONTEROSATO,  Enum.  e  Sinon. 
p.  17.-  Bn>.  DM  i/.  et  DOI.I.F.,  Moll.  Mar.  du  Rouss.  i.  p.  489,  t. 
61,  f.  4-6,  t.  62,  f.  4.— LOCARD,  Coq.  Mar.  des  Cotes  de  Fr.,  p.  232 
(1892).—  Ch.  ,  EtaBO,  Hist.  Eur.  M.-rid  iv,  p.  268.— Ti  m  1:1. 

Bull,   della  Soc.  Malac.   Ital.   iii,  p.  145. —  Chiton  siculus  GRAY, 
Spicil.   7,ool.,    p.  .", ;   Pun..,    Knuiii.    Moll.  Sicil.   ii,   p.  S2.—  Wrix- 
KAUKI,  Conchyl.  «l<-s  Mittdm.  ii,  p.  408.— REEVE,  Conch.  Icon.,  t. 
">;  t.  16,  f.  97  (lowest  fig.);  t.  19,  f.  12l.—  Gli/mnopl>ix 


<  III 


K".  mm:.,  NOIIV.  .  \n-h.du  Mn~.  1^*1,  p.  242,      '  'A///,//  ;,/,///  |)i-n. 
(not  IMiil.      I  de  Morfe,  iii,    |>.    132;    Lamk.  .-.lit.  Dl,.,  vii, 

]).  .~>(U.  —  C.  #<iniiiiimiifomi*  I  )ni.i.i  I  "s.  (  ';il;il.  I'alava-.  | 

Doubtful    synonyms:    /,«/>/////•//>•  .<irn/  H*  forma   africana  Rod  1  1 

BBUNE  Journ.  de  ConchyL  (3)  \\i,  p.  -I'J  M881).  —  Chiton  str 

Ciiir.i:i:«.niM   .UN.  BBT78IN1    I  psa   ('liicr.    (  'onchyl.  p.  44  (1870).  — 
r//.  fstinirii  ('1111:1:.,  MS.  liurs.,  f.  /•.,  p.  -I-"). 

This  common  Mediterranean  specie.-  is  very  variable  iii  color,  as 
the  ii.irim-s  show,  hut  quite  constant  in  sculpture.  Tlic  valves  are 
generally  very  much  elevated,  like  a  gothic  roof.  The  prominence 
of  tin-  mucro  or  heak  of  the  tail-valve,  and  its  central  position,  are 
characters  showing  the  strong  bond  of  affinity  between  olivacens  and 
the  Australasian  species,  and  sundering  it  from  the  somewhat 
similarly  sculptured  West  Indian  forms.  Issel  and  the  authors  of 
Molln&nn.'*  Mai-ins  du  Roussillon  classify  the  color-forms  of  this 
species  into  two  groups  :  (1)  those  which  are  variously  marbled  and 
spotted,  and  (2)  those  which  are  unicolored,  forming  the 

Color-  var.  unicolor  Issel.  Entirely  white,  tawny  or  red.  It  is 
likely  that  C.  rnbellus  of  Nardo  was  founded  upon  an  individual  of 
the  last  color. 

I  regard  it  as  probable  that  the  Lepidopleurm  corallinus  of  Risso 
(Hist.  Nat.  TEur.  Merid.  iv,  p.  268)  was  based  upon  a  red  example 
of  C.  olivucens.  Monterosato  has  suggested  that  corallinus  is  the 
same  as  rubicundus  Cosfa+scytodesma  Scac.,-\-freelandi  Fbs.-f- 
pulc/tellus  PblL-\-philippii  Issel  (see  Journ.  de  Conch.  1878,  p.  146). 
This  identification  seems  to  me  to  be  quite  inadmissible. 

Rochebrune  describes  a  '  forma  '  Africana  as  follows  :     Allied  to 
L.  siculus,  but  differs  in  having  the  valves  obtusely  carinated,  the 
sulci  of  the  .central  areas  very  delicate,  straight.     Length  26  mill. 
Promontory  of  Cape  Verde,  and  Table  Bay,  Cape  of  Good  Hope. 

The  reference  of  this  form  to  the  present  species  is  doubtful. 

C.  AFFINIS  Issel.     PI.  35,  fig.  93  (enlarged.) 

Shell  oblong,  subcarinated,  smooth,  painted  with  various  colors  ; 
end  valves  radiately  ribbed,  the  front  valve  having  about  21  ribs, 
concentrically  striated  ;  the  other  valves  having  longitudinal 
arcuate  grooves  ;  lateral  areas  narrow,  triangular,  transversely  tri- 
sulcate.  Girdle  minutely  scaly. 

Length  18,  breadth  11,  alt.  6  mill.     (Issel.) 

GnlfofSnez. 


1M>  <  IIITON. 

SAVK.NV,  iWript.  de  1'Egypte,  Gasterop.,  t.  3,  f.  9.—  Chiton 
Malar.  Mar  Kosso,  p.  234  (1869). —  C.  .«<V/////x  <iray, 
COOK i- .  Ann.  Mag.  N.  H.  1885,  p.  275.— E.  A.  SMITH.  IW.  /ool. 
Soc.  Lond.  1891,  p.  392. 

I  have  not  seen  this  species,  which  is  considered  by  Cooke  and 
Smith  to  be  synonymous  with  the  common  Mediterranean  C.  x/V///*/s 
of  Gi  iceua  Spengl.).  Smith  says  that  it  "  may  be  regarded 

as  a  stron.L'ly  marked  form  of  the  Mediterranean  species.  There  is 
also  a  species  found  in  New  Zealand,  C.  siculoides  Cpr.,  MSS.=  C. 
wens  Reeve,  which  is  also  inseparable."  As  I  do  not  know  that 
Mr.  Smith's  opinion  is  founded  upon  a  study  of  the  inside  as  well  as 
the  external  characters,  I  prefer  to  retain  C.  affinis  as  a  distinct 
species  for  the  present,  although  it  is  certainly  closely  allied  to  C. 
olimren.4.  Issel  gives  both  figs.  8  and  9  of  Savigny's  plate  as  illus- 
trations of  his  species,  but  his  description  applies  only  to  figs.  9. 
Savigny's  figs.  8  represents,  in  all  probability  Callistochiton  adenensis 
Smith. 

C.  RUBICUNDUS  Costa.     PL  45,  figs.  73,  74,  75. 

Shell  similar  in  form  and  color  to  Trachydermon  rnber,  but  much 
smaller;  subelongate,  much  elevated,  the  valves  beaked;  dorsal 
ridge  very  acute ;  mucro  median,  elevated.  Entire  surface  micro- 
scopically granulose,  the  central  areas  having  spaced,  longitudinal 
parallel  sulci,  6  to  9  on  each  side;  lateral  areas  snbelevated,  smooth. 

Inside  having  8-10  slits  in  the  anterior  valve,  1  in  the  central 
valves,  9  in  posterior  valve  ;  teeth  acute,  but  all  distinctly  serrated  : 
eaves  moderate;  sinus  moderate;  sutural-plates  joined  by  a  si.iall 
serrated  lamina. 

Girdle  regularly  imbricated  with  large,  solid,  smooth  scales. 

Length  8$,  breadth  5  mill. ;  divergence  80°. 

Length  6,  breadth  24  mill. 

A,    Philippi)  ;  Dalmatia  (Mus.  M'Gill  Coll.  and  Acad.   Nat. 
I'hila.) 

Chitnn  rnb,'rundu8  O.  G.  COSTA,  Catalogo  sistematico  e  raLri«mat«> 
de1  Tortaori  d«-lhi  due  Sicilie,  p.  i,  iii,  t,  1,  f.  2  (Naples,  1829);  Fauna 
di  Napoli,  Aniiu.  Mulli,  Chiton,  p.  8. —  Chiton  j»<l<-hf//ti.<  Pim.irri, 
KIIUIII.  M..I1.  Sicil.  ii.  p.  83,  t.  19,  f.  14.— Chiton  rubella*  Cnt.,  M*. 
olim,  and  C.  /'•„/•,////////.<  Cri;..  V\ 

Doubtful  synonyms:  Ch.  free  law  fi  PORBEB,  I{»-|>.  Ai-ir.  Invert., 
in  K«-p.  i::th  in.M-tin-  Urit.  Asso.  Adv.  Sci.,  for  184:;.  ,,.  i-s'^j  (1844). 
—  C.  scytodern  .\\,  < '.  /,// /'//;>;, // 


.  111  roiTi 

The  prominent  features  of  this   little  sprri»-  >lor, 

Lrreat  elrvatioli.  like  a  -"thie  roof,  and  the  sculpture. 

Thi-  ifl  imt  identical  with    the    LepidopleUTUA  mr<i//imi 

.  as  Montero.-ato  has  said.  It  is  impossible  {'or  me  to  believe 
that  Kisso  would  have  used  the  words  "  avec  le-  .'l.'vat  i«.ns  lah'rales 
bisul<pi«'es  "  if  he  had  hern  desci'ihinir  (  '.  riiln'riiinhi.<.  The  identi- 
fication of  the  learned  authority  on  Mediterranean  -hell.-  \\as  not 
founded  upon  an  examination  of  UHSO'S  type. 

('.  HAM vi  Koehehnme.     I M.  35,  figs.  85,  86. 

Shell  ovate-elongate,  carinated,  green,  /xiintrd  loiif/ifudlimf/i/  ////'/ 
regularly  u'ith  altti'iiafhiy  linr*  of  n'hite,  bine  and  huff.  Head  valve 
l-itfi-'il  areas  and  posterior  areas  of  the  tail  valve  sculptured  n'ifh  *frong 
concent r ii-  ridges,  which  are  irregular  and  as  if  imbricated;  central 
areas  having  7  utrong,  iridc,  obliquely  curved  ribs,  the  middle  smooth. 
Girdle  scaly,  scales  rounded,  very  shining. 

Length  23,  width  12  mill.     (Rochebr.} 

Strait  of  St.  Lueie,  Cape  Verde  Is. 

Gymnoplax  hamyi  ROCHEBR.,  Bull.  Soc.  Philom.,  Oct.,  1881  ; 
Nouv.  Arch,  du  Mus.  (2)  iv,  p.  242,  t.  17,  f.  13a,  c  (1881.) 

Allied  to  C.  concentricus  Reeve,  but  distinguished  by  the  imbrica- 
tion and  irregularity  of  the  concentric  Ftrine  of  the  end  valves  and 
lateral  areas,  by  the  width  and  small  number  of  grooves  on  the  sides 
of  the  central  areas,  and  the  absence  of  a  mucro  on  the  tail  valve. 
(Eochebr.) 

The  references  to  the  figures  of  this  species  and  C.  insularis  are 
transposed  in  Rochebrune's  publication. 

C.  INSULARIS  Rochebrune.     PL  35,  figs.  83,  84. 

Shell  ovate,  elongate,  subcarinated,the  carina  obtuse  ;  olivact- 
sparsely  spotted  with  white;  anterior  valve  and  posterior  part  of  the 
tnil  rnli'e  Sculptured  n'itli  i-ndinti/ig,  interrupted,  feeb/i/  grilling  r//»-; 
median  valves  having  the  centra/  urea*  *innntli  in  the  middle,  *nlc<ited 
at  the  */Vf.?x,  the  «H/CI  H/IC<JH<I/,  bmcenJute,  pointed  at  the  ends,  con- 
centrically arranged ;  lntr,-<il  ami*  /luring  hrnm-hiinj  i-ndiufiin/  /-/Ax. 
Girdle  olive  marked  with  wliite  spots,  scaly,  the  scales  minute. 
(Hnrh.hr.}  Length  '11,  breadth  1  o  mill. 

Strait  nf  St.    Vni<->  at,   <'"i»     ]'>,•>!•    A. 

Qymnoplax  ///.<//A//-/x  ROCHKIII:..  Nouv.  Archiv  du  Mus.  ('!)  iv,  p. 
243,'t.  17,  f.  12«,  b.  (1881.) 

Conijtare  ('//.  oftvoeeu* 8pengL 


1M  CHITON. 

C.  LYRATUS  Sowerby.     PL  31,  figs.  35,  36. 

slu'll  oval,  smooth  ;  hack  Bubangulaied  ;  lateral  areas  subelevated, 
smooth  :  central  aivas  longitudinally  li  rate  at  the  sides;  girdle  broad, 
minutely  scaly.  Length  37,  breadth  1~>  mill.  (Sowb.*) 

This  shell  is  ><>  thin  as  to  be  nearly  transparent;  it  is  smooth, 
ratlin-  amrulated  in  the  center,  the  lateral  areas  smooth,  slightly 
elevated,  the  central  areas  marked  with  faint  longitudinal  ribs.  The 
margin  is  covered  with  regular,  minute  scales.  The  general  color 
is  drab,  variegated  with  brownish  concentric  lines  at  the  sides  and 
reddish-brown  dorsal  bands  on  some  of  the  valves.  (Swb.) 

Jfnltitiit  Hiihnoirn. 

Chit'm  ////•'////>•  Sown,  in  Charlesworth's  Mag.  of  Nat.  Hist.  1840, 
p.  293  ;  Conchol.  Illustr.,  f.  126.— REEVE,  Conch.  Icon...  f.  110. 

This  shell  should  be  compared  with  w//'//-fV//*/x  Orb.  and  tli.<- 
.«ini!/i*  Reeve. 

Carpenter  has  described  a  C.  xr////A/-/-/'x  in  MS.  from  Cumingian 
specimens  of  unknown  locality.  It  will  probably  prove  to  be  a  form 
of  the  above  species. 

Reeve  reports  C.  lyr'tin*  from  Prince  Island,  West  Africa,  under 
stones. 

C.  DISSIMILIS  Reeve.     PI.  37,  fig.  11. 

Shell  oblong-ovate ;  terminal  valves  and  lateral  areas  longitu- 
dinally grooved,  smooth  in  the  middle  ;  variegated  with  reddish- 
brown  ;  ligament  granosely  coriaceous,  tessellated.  Approximating 
in  some  measure  to  the  C.  tu/ijut.  (J£mr.) 

Ifufiifilt   nnkiinirii. 

C.  f//W//////*  RKKVK,  Conch.  Icon.,  t.  25,  f.  170  (May,  1847.) 
Reeve  s  description  does  not  correspond  very  well  with  his  figure ; 
and  the  species  will  probably  prove  to  be  the  same  as  C.  mnnrii  //>•/.< 
Orb. 

Carpenter  notes  that  in  Reeve's  type  specimen  the  whole  surface 
is  conspicuously  quincuncially  granulated.  The  anterior  valve  has 
9,  central  1,  posterior  valve  13  slits;  teeth  sharply  pectinated.  It 
measures,  length  18,  breadth  9  mill. ;  divergence  90°. 

C.  CAN  M:M .Nsisd'Orbiirny.     IM.  :!4,  figs.  77,  78,  79. 

Shell  oblong:  carina  smooth,  central  areas  of  the  valves  longitu- 
dinally sulcated,  lateral  areas  smooth;  ends  smooth:  margin 
granulate-scaly.  Length  -J4,  width  12  mill.  (Orb.) 


CHI 

The  shell  is  oldon-,  a  1  it  I  le  ea  ri  mite,  I  ;   the  intern 
xillnnf/i  nt  tin    fiiriiiii,  iiKirlcrtl  nu   <  nr/i  *i<l<     //•/'///    *lr<nnj    ,  ':it<'d 

l>y  deep  grooves;  the  /»//»/•»//  <n-«^  an  </////•////  .<////»o///,  :is  well  as  the 
end  valvrs.  The  -ii'dle  is  wide,  exten-il.le,  covered  with  little 
oblong.  smooth  ami  polished  scale-,  larire.-t  in  the  middle  of  its 
width. 

The  coh>i>  are  verv  variahle  :  sometimes  marbled  with  Mark  and 
brown  spots  on  a  white  ground,  sometimes  with  some  valves  quite 
Mack  or  ^roi'ii.  the  others  spotted.  Tin-  irirdle  i>  radiated  with 
Mark,  gray  and  white.  (Orb.} 

CHIHH-II  [«.  (Webb  and  ]>erthelot.) 

(  '.  rinmrieii*i«  OKI;.,  in  Webh  tt  Berth.,  Hist.  Nat.  des  lies  Canaries, 
Moll.,  p.  !W.  t.  7,  f.  16-11).  —  Chiton  (JLophurw?)  riiiini-irii.*!*,  SHUTTLW., 
Bern.  Mittheil.  1853,  p.  81. 

Allied  to  C.  o///wr//x,  but  differs  in  having  the  lateral  areas  and 
end  valves  smooth.  The  interior,  according  to  Shuttleworth,  is 
green,  with  spots  of  rose  and  purple.  This  species  should  be  com- 
pared with  C.  lifrntti*  Sowb. 


C.  TULIPA  Quoy  &  Gaimard.     PI.  31,  figs.  43-49. 

Shell  oval-oblong,  elevated,  acutely  carinated,  the  side-slopes 
nearly  straight.  Snri'nrr  #ntonth  and  polished  throughout.  Ground- 
color buff  or  whitish,  suffused  and  closely  mottled  all  over  with  red- 
dish-chestnut, fawn,  or  purple-brown  ;  usually  longitudinally  streaked 
on  the  central  areas,  zigzagged  or  tessellated  on  the  end  valves,  and 
articulated  on  the  diagonal  lines  with  the  darker  color.  Sometimes 
parts  of  some  valves,  or  several  whole  valves  are  of  a  uniform  dark 
brown  color  (figs.  43,  45.) 

The  central  areas  are  smooth  except  for  slight  growth-lines  and  a 
microscopic  granulation  which  covers  the  whole  surface.  Lutrnil 
areas  /'>//  /•<//>"/,  flat,  rarely  with  slight  radii,  smooth.  In  the 
excavation  at  the  diagonal  line  a  lens  shows  a  few  very  short  longitu- 
dinal grooves,  in  some  specimens.  Tail  valve  elevated,  //•////  rr///,W 
wnbo. 

Interior  very  light  blue-green,  each  valve  rayed  with  brown  at 
the  beaks.  Anterior  valves  having  8,  central  valves  1,  posterior 
valves  12  slits;  teeth  pectinated.  Eaves  short,  spongy,  grooved 
along  the  teeth.  Sinus  narrow,  denticulate. 


186  i  III  TON. 

<  iirdle  solid,  closely  covered  with  smooth,  convex  scales. 
Length  43,  breadth  25  mill.  ;  divergence  105°. 
Length  38,  breadth  '27  mill.;  divergence  100°. 
Length  33,  breadth  24  mill.;  divergence  112°. 

Cape  of  Goo<l  II»rl  . 

Cli'itm,  tuHjin  (JuoY  &  GAIMARD,  Y<>y.  de  1'Astrol.  Zool.,  iii,  p. 

389,  t.  74,  f.  35-36  (1834).—  KRAUSS,  Die  Sudafric.  Moll.,  p.  37.— 

C.  t'ljmltinhi  SOWERBY,  Charlesworth's  Mag.  of  Nat.  Hist.  1840,  p. 

Conch.  Illustr.,  f.  45,  and  var.,  f.  85,  86.—  REEVE,  Conch.  Icon., 

t.  3,  f.  18. 

?  C.  politits  SPENGLER,  Skrivter  af  Naturhist.-Selskabet,  iv,  p. 
89,  17l»7. 

A  smooth,  polished  species,  excessively  variable  in  color  and 
pattern.  The  short  traces  of  grooves  at  the  diagonal  line  are  rarely 
visible  without  a  lens,  and  are  completely  obsolete  in  many  spec- 
imens. The  smooth  surface  and  unusual  coloring  are  the  more 
striking  characters  of  the  species;  but  the  strongly  raised  lateral 
areas  and  the  central  mucro  at  once  separate  it  from  C. 
,  etc. 


C.  RUSTICUS  Deshayes.     PL  31,  figs.  32,  33,  34. 

Shell  ovate-oblong,  depressed,  the  jugum  rounded  ;  very  dark 
green,  much  paler  beneath. 

Entire  surface  quincuncially  granulose.  Central  areas  with  no 
other  sculpture,  but  at  flu-  ilui<j<>n<il  //'//«"  th>rr<n-<  <>//  e<i<-Ii  .«'i<l<  10-15 
-•Ao,7  l>nf  <!,<  t,  <j  moves.  Lateral  areas  swollen,  and  having  n  f>  n- 
indistinct)  obsolete  swelling  rib*,  or  rather,  obsolete  knobs  irregularly 
coalescing  into  indistinct  ribs;  blotched  with  paler.  End  valves 
similarly  sculptured  and  blotched,  beak  of  the  tail  valve  in  front  of 
tin  middle,  the  slope  behind  it  a  trifle  concave. 

Interior:  anterior  valve  having  !»,  central  valves  1,  posterior 
valve  12  slits;  teeth  pectinated  ;  eaves  short;  sinus  moderate,  with 
about  13  teeth. 

<  Jirdle  dark  olive,  like  the  valves  ;  covered  with  very  large  stout 
scales. 

Leiurth  '24.  breadth  15,  alt.  6  mill. 

Length  L'n.  bivadth  l-'J  mill.:  divergence  1  15°. 

<in<I 


.    Ill  H.N. 
C.    I  I>H..    Moll.    K.   MM.,    p,    89,     t.    ft,     !'.      1      3,         (     ;  1,     J). 

C,     /,'///'/«/'/"'/•«  .Mr-,  in  Mol.iu-    i  li  Mauri- 

tius, p.  oIKI. 

This  species  has  considerable    resemblance   :  l>ut 

the  lateral  arca<  and  end  valves  an-  le.-s  Btronglj Sculptured  and  the 
longitudinal  rihh-ts  arc  lacking  on  the  central  areas  except  at  the 
diagonal  lines.  The  above  description  is  from  Carpenter's  J/>. 

C.  ANGUSTlco>r\  n>  <,Juoy  iV  (iaiinanl.      IM.  :51,fii:s.  -'IT, 

Shell  ovate,  wide,  little  elevated,  depressed  hehind  hy  the  prom- 
inence of  the  anterior  valve.  The  third  to  the  seventh  valves  are 
excessively  narrow,  arcuated  hehind.  with  a  little  median  projection, 
which  contributes  to  form  a  dorsal  carina.  The  last  valve  is  the 
largest  of  all,  nearly  orbicular;  the  second  valve  is  next  in  size,  the 
intermediate  valves  being  about  equal.  Sutural  plates  narrow, 
separated  by  a  wide,  flat,  sinus ;  insertion-plates  denticulate.  The 
end  valves  have  striated  teeth.  The  entire  interior  is  a  pretty  green  ; 
and  this  we  suppose  to  be  the  color  of  the  outside,  but  it  is  eroded. 
AVe  think  it  is  striated  like  our  C.  rtritlf*.  The  girdle  is  scaly,  the 
scales  oval.  Length  22,  width  16,  alt.  8  mill. 

Lie  of  Fi'min; 

C.  (ni</n«t;co«t>itn*  Q.  &  G.,  Voy.  Astrol.  iii,  p.  398,  t.  73,  f.  4,  4'. 

The  entire  substance  of  Quoy's  description  is  rather  freely  trans- 
lated in  the  above  paragraph.  It  is  very  likely  that  this  is  merely  a 
greatly  worn  specimen  of  C.yW//xxoyyr////x  Q.  &  G. 

( '.  NKiKoviiMiNS  Blainville.     PI.  31,  figs.  41,  42  (enlarged.) 

Shell  ovate,  moderately  elevated,  the  dorsal  ridge  obtuse ;  black- 
ish. Mucro  in  front  of  the  middle,  little  raised,  the  slope  behind  it 
straight. 

Valves  obtusely  beaked;  entire  surface  minutely  quincuiK-ially 
•rranulated;  jugal  area  smooth,  often  eroded;  central  areas  having 
about  30  delicate  lirulse  on  each  side,  parallel  to  the  dorsal  ridge, 
sometimes  eroded  ;  lateral  areas  moderately  raised,  having  6  to  8 
delicate  granulose  riblets,  the  intervals  Hat. 

Interior:  anterior  valve  having  12,  central  valves  1,  posterior 
valve  14  slits;  teeth  short,  obtuse,  coar.-ely  pectinated;  eaves 
small  :  sinus  wide,  flat,  12-toothed. 

Girdle  covered  with  solid,  smooth,  lanre  and  rounded  imbricating 
scales.  Length  17'.,  breadth  10  mill.;  divergence  117°. 

•/  H<>i» . 


188  (  IIHON-SCLEROCIIITON. 

Chiton  nigrovirent  P>LAINVIU,E  Diet.  Sci.  Nat.  xxxvi,  p.  538 
(1825).—  HADDON,  Challenger,  Polyplac.,  ]>.  22.—  C.operMU  GRAY, 
Spicil.  Zool.,  p.  5  (1828).  —  HANLEY,  in  Wood,  Index  Test.  Suppl. 
t.  1.  f.  LI.—  REEVE,  Conch.  Icon.,  t.  22,  f.  151.—  KK.U--,  Die 
Siidafric  Moll.,  p.  37. 

C.  TENUISTRIATUS  Sowerby.     PI.  38,  figs.  27,  28. 

Shell  oval,  carinated,  the  back  elevated  ;  valves  all  over  very 
finely  radially  striated;  girdle  scaly. 

Length  25,  width  15  mill.     (So>r/,.j 

A  neat  little  shell  of  a  dark  olive-green  color,  oval,  elevated, 
nearly  smooth  in  appearance,  but  finely  striated  ;  margin  lighter 
green  than  the  rest  of  the  shell;  inside  bluish-green.  (Sotcb.) 

Habitat  inihiiinri,  (Mus.  Stainforth.) 

C.  tfimlxfrinfii*  SOWB.,  in  Mag.  Nat.  Hist.  1840,  p.  291  ;  Conch. 
Illustr.,  f.  135,  135. 

This  is  apparently  a  typical   Chiton,  closely  allied  to  qnoyi  or 
,  but  it  seems  to  be  more  elevated  than  either. 


C.  MAURITIANUS  Quoy  &  Gaimard.     PI.  31,  figs.  39,  40. 

Shell  small,  oval,  elongated,  the  valves  elevated,  carinated,  trans- 
versely finely  striated  and  having  lateral  areas  over  which  the  stria- 
pass.  It  is  a  very  dark  green,  lighter  at  the  ridge,  and  at  the  edge 
of  the  girdle,  which  is  covered  with  fine,  close,  rounded  scales,  and 
marked  with  18  brown  bands.  Branchial  leaflets  about  38  on  each 
side.  Length  18,  breadth  10,  alt.  6  mill. 

Mauritius. 

r.  mawritianu*  Q.  &  G.,  Voy.  Astrol.  iii,  p.  397,  t.  73,  f.  J-3.— 
L'j,itli,l,/,  a,  -ii."  mini,  -H'mit  a*  MARTENS,  in  Mobius'  Reise  nach 
Mauritius,  p.  300. 

Known  only  by  the  original  description,  which  is  far  from  being 
satisfactory.  The  interior  has  not  been  described.  It  is  a  more 
carinated  species  than  C.  quoyi,  and  the  striation  is  in  a  different 
direction  ;  the  girdle  also  being  banded  with  brown. 

Section  SCLEROCHITON  Carpenter,  1892. 

'eroeh&m  CIM:.,  .l/\,  in  Dall,  Proc.  U.  S.  Nat.  Mus.  1881,  p. 
284,  287,  289  (no  type  mentioned.) 

Teeth  of  the  tail  valve  turned  forward,  blunt  and  pectinated  ; 
sinus  smooth,  not  denticulate;  scales  of  girdle  solid,  striated, 

uted. 


OHITOK    i:  LDflJ  \. 

This  section  or  sabgeniu  represents  a  further  development  of  the 

AcMiithoplcuroid  characters  which  sonic  A  uM  ralasian  ,-peries  of  the 
restricted  p-nus  ChUmi  a-.-ume.  In  ("//.  /»  ///.•»•/ ,-/»  ////'-,  lor  example, 
the  'micro  is  median,  the  posterior  teeth  tend  forward  .-om»-wh;i- 
sinu-  i-  smooth  or  only  very  ohsoletcly  denticulate,  and  the  girdle- 
scales  are  striated  and  rather  separated.  I"  &-i,-,'n<-hiin,i  the  mucro 
is -lightly  more  posterior,  the  teeth  slightly  more  tilted  forward  ; 
the  sinus  is  smooth,  and  the  girdle  scales  still  more  separated.  ('I. 
il*  could  be  placed  almost  as  well  in  Schrncliitnn  as  in 
8.  *. ;  the  necessity  of  reducing  Sclerochiton  to  the  rank  of  a 
section  under  (1liifnn  will  therefore  be  apparent.  The  girdle-scales 
hear  a  certain  resemblance  to  those  of  En<>i>I<x-liit<>n,  but  this  is  a 
purely  accidental  similarity,  dependent  upon  their  separation  on  the 
surface  of  the  girdle. 

C.  MILES  Carpenter,  n.  sp.     PL  46,  figs.  1,  2,  3,  4,  5' 

Shell  solid,  rugose,  oval,  depressed,  generally  eroded ;  dorsal 
ridge  rounded,  hardly  defined ;  mucro  behind  the  middle,  nearly 
flat;  apices  of  the  valves  prominent,  obtuse.  Ashen,  spotted  with 
black-brown.  Central  areas  transversely  pretty  regularly  riigulose, 
the  wrinkles  appressed  ;  lateral  areas  hardly  elevated,  moderately 
well  denned,  conspicuously  rugose,  rugae  subradiating,  granose ;  the 
end  valves  similarly  sculptured. 

Interior  having  the  anterior  valve  with  about  11,  central  1,  pos- 
terior valve  obscurely  9-11,  slits.  Teeth  of  posterior  valves  directed 
forward,  strongly  callosed  inside  above  the  slits,  sulcate  outside ; 
the  rest  of  the  valves  having  the  teeth  sulcate  outside  and  pect- 
inated at  the  margins.  Eaves  moderate,  solid,  deeply  grooved. 
Sinus  deep,  wide,  wavy,  smooth  ;  sutural  laminae  united. 

Girdle  (pi.  46,  fig.  1.)  maculated,  ornamented  with  large,  solid, 
more  or  less  separated  scales  which  are  striated  outside  ;  no  hairs. 
(Cpr.}.  Length  30,  breadth  17*  mill. ;  divergence  130°. 

Tnrrr*  Sf  I'll  iff  (Mus.  Cuniing,  no.  42.) 

A  variety  is  described  as  being  a  little  narrower,  and  blackish, 
hardly  maculated. 

Section  KADSIA  Gray. 

i;,i,l*i>i  (  JIIAY,  P.  /.  S.  1847,  p.  126.     Type  Ch.  /*/,•//- 
Girdle  and  shell  like   C/iiti>//,  except  that  the  insertion-plates  of 
the  intermediate  valves  have  two  or  several  slits. 


I'.il)  CH3TON-RAD8IA. 

Carpenter's  opinion  of  the  small  importance  of  the  character  upon 
which  this  Lrroiip  is  founded,  is  fully  supported  by  the  material 
studied  by  myself.  lie  writes  as  follows:  "The  bi-  or  tri-slitting 
of  the  lamina1  appears  to  me  a  character  of  very  secondary  impor- 
tance, as  Ix-iiiLf  merely  numerical,  not  structural,  and  as  being  very 
variable  even  in  the  same  specimen.  In  one  specimen  of  Dr.  Gray's 
type  which  I  received  from  Mr.  Cuming,  only  one  r<i/r>  /mil  fm>  >•///.< 

»-h  >/'/<;  most  of  the  other  valves  had  one  only  ;  sometimes  a 
second  slit  was  seen  on  one  side.  For  such  a  specimen  it  would  have 
been  as  useless  to  establish  a  genus  as  for  C//.  i'!i-i/n/ntu.«,  or  for  C. 

a  1  1  in  which  Dr.  Gray  found  the  same  abnormality  (vide  P.  Z. 
S.  1847,  p.  127).  Another  specimen  of  C.  burnt^ii  had  the  valves 
either  with»one  slit  or  with  two  slits  on  each  side,  or  with  one  on  one 
side  and  two  or  three  on  the  other.  Under  these  circumstances  I 
cannot  regard  the  number  of  slits  as  a  generic  character." 
Compare  alse  the  notes  under  C. 


Key  to  species  of  Ji<n1*i'i. 

<i.  Surface  smooth,  goodwill. 

tin.  Surface  sculptured  with  riblets. 

b.  Ribs  strong  and  coarse  ;  color  black-olive,  uniform, 

aulcatus. 

/>!>.  Riblets  fine;  color  variegated. 

c.  Ribets  of  central  areas  nearly  obsolete  ;  of  lateral  areas 

irninose,  Imrin-xii. 

cc.  Riblets  of  central  areas  fine,  distinct  ;  shell  olive  mottled 

with  dark,  . 


C.  BAI:NI>H  (  iray.     PL  29,  figs.  10,^1,  12. 

Shell  oval,  J/y,,v.<x/f/,  scarcely  carinated.  Black-brown,  yellowish 
toward  the  ridge  where  each  valve  generally  has  a  dark  triangular 
spot,  ami  having  a  butt-white  longitudinal  stripe  on  each  side; 

Lfirdle  L'lven. 

areas   raised,  sculptured  "•/'//<  nlnmt  (5  in-i-i/utti,-,   >n,, 
///o//x   nulinfinfi    /•//>.>-.      Ccnfriif  OfOtU   .<>-ii/j,fii,-><l    //•//// 
longitudinal   /-/'////Vx,  .v//AoA.vo///r  fmnn-il  tli>    i1nr*nl  /vWy,  and  some- 
what   latticed    by    growth-lines.       Knd     valves    having    radiating 
nodulous  ribs;    mnfm  <n  tli<  j,,,.^,  ,•',,,,•  r<ilr,   very  ,,<«r  f  In-  front  in<r,-(/i/i. 
Interior    whitish  ;  sinus    finely    and    rather    unevenly    toothed. 
rioi  \al\c  haviiiLr  l."i-li;,  central  valves  2,  (occasionally  1  on 


OBZTOV-RAD8IA,  I'.'l 

•_'  on  tin-  <>thrr  .  potterior  valve  L8-19  ilita    Teeth  l>lmit, 

pertinat.  narrow,  SpOB 

(Jirdle  eovrre.1  with  sliiniii-,  o.nvex,  minutely  ,-triated  scales. 

n't  in  !><>,   (  '/////. 

( liitnn  tarn«§t»  GBAY,  Spirii.  7<>ol.,  p.  r>,  t.  6,  f.  22. — Sown,  in 
M..11.  Beechc}-  Voj.,  p.  HH,  t.  11,  f.  10;  Conchol.  Illustr.,  f.  2.— 
REEVE,  Conch,  Icon.,  1. 1,  f.  1 ;  t.  21,  f.  137. 

Kntirely  different  from  the  other  species  of  Radxia  in  form  jind 
sculpture.  The  rihlets  upon  the  central  areas  are  very  fine  and 
their  interspaces  shallow.  Occasionally  a  specimen  occurs  having 
some  of  the  valves  with  a  single  slit  one  side. 

C.  GOODALLII  Broderip.     PL  29,  fig.  9 ;  pi.  28,  figs.  5-8. 

Shell  very  large,  oval,  moderately  elevated,  carinated,  the  side- 
slopes  nearly  straight  or  rather  convex.  Surface  nearly  smooth. 
Color  blackish,  olive-black  or  brown-black,  generally  showing  an 
obscure  olive-green  stripe  on  each  side  of  the  keel.' 

The  lateral  areas  are  a  little  raised,  separated  by  an  obtuse  ridge 
from  the  central  areas,  and  in  most  specimens  they  are  son/new  In  it. 
t<  miri'il  IHJ  roiii-i'utrlr  mark*  of  groicth-arrest.  There  is  no  other  >sru/jit- 
?'/•>  <>n  i  iflii'r  c>  ,it,;il  nr  lateral  areas  except  an  extremely  minute  and 
even  granulation  over  the  whole  surface.  The  umbo  of  the  posterior 
nifr,:*  !*  u ii ii.<uallij  urn r  f/ti'  front  margin. 

Interior  white,  each  valve  having  a  pair  of  posterior  rays  and  a 
central  spot  of  brown.  Sutural  plates  broad,  sinus  rather  shallow 
having  about  8  teeth.  Anterior  valve  having  25-26,  central  valves 
2-3,  posterior  valve  26-28  slits ;  teeth  stout,  blunt,  deeply  pectin- 
ated ;  eaves  very  spongy. 

Girdle  covered  with  coarse  flattened-convex  scales. 

Length  110,  breadth  70  mill. 

Qafapag 

Chiton  i/onil,,//;;  BROD.,  P.  Z.  S.  1832,  p.  25.— C.  godallii  SOWB., 
Conch.  111.,  f.  34,  40.— C.  goodalli  REEVE,  Conch.  Icon.,  f.  8.— 

Jiuilsin  t/onilit//!  Cl-JI.,  -V-S'. 

This  very  large  smooth  species  is  quite  unlike  any  other. 

C.  SULCATUS  Sowerby.     PL  28,  figs.  1,  2,  3,  4. 

Shell  oval  or  oblong,  moderately  elevated,  carinated,  the  side- 
slopes  nearly  straight;  of  a  n»/j'i>rin  olwe-blaehj  or  having  the 
lateral  areas  obscurely  purple-black. 


EUDOXOC  ill  I 

Lateral  area-  .//<////  /•"<//'"/'///  rilili»1  and  grooved,  the-  • 

terior  rib  of  each  valve  broad  and  crenulated,  the  other  ribs  mutual, 
varviiiLr  in  number,  usually  split  toward  the  outer  ed^e  of  the  shell. 
(  'entral  areas  sculptured  with  numeroifs  strong  but  smaller  ribleta, 
\vhich  near  the  dorsal  ridge  converge  forward,  but  on  the  pleura 
they  diverge  strongly.  End  valves  having  strong  radiating  ribs, 
which  split  toward  the  periphery.  Umbo  of  posterior  valve  prom- 
inent. in  front  of  the  middle. 

Interior  blue-green  ;  sutural  plates  broad;  sinus  rather  deep  and 
square,  finely  toothed.  Anterior  valve  having  23-26,  central  valves 
2-3,  posterior  valve  18-20  slits;  teeth  stout,  blunt,  finely  and 
strongly  pectinated.  Eaves  coarsely  spon.iry. 

Girdle  covered  with  coarse  convex  scales,  larger  toward  the 
periphery.  Length  95,  breadth  55  mill. 

Qalapag 

Chiton  *nlr«hi8  WOOD,  Gen.  Conch.,  p.  16,  t.  3,  f.  1.  —  Sown., 
Conch.  Illustr.,  f.  12.—  REEVE,  Conch.  Icon.,  f.  15.  —  R<nl«i<i  tulcata 
CPR.,  M\ 

This  is  one  of  the  most  strongly  sculptured  of  all  Chitons,  and  is 
correspondingly  easy  to  recognize.      There  are  usually  two  slits  in 
each  side  insertion-plate,  but  the  second  valve  occasionally  h; 
many  as  four. 

C.  (Rnd*ia)  ccerut'->«-eit«  Slmttleworth,  Diagn.  n.  Moll.,  no.  4,  in 
Bern.  Mittheil.  1853,  p.  65.  Xo  description  of  this  species  has  been 
published.  It  is  said  to  be  from  California.  Possibly  founded  on  a 
Ch.  ciri/H/iitn*,  q.  V. 


Genus  XIII.  EXJDOXOCHITON  Slmttleworth,  1853. 
Eudoxochiton  SHUTTLW.,   Bern.  Mittheil.   hsr>3,  p.  C>7,  type  A. 

unhil'i*  (  lUAY.  —  Aoiiithn/t/rnt'ii  SCCt.  *  *  f,    GRAY,    P.    Z.    S.    1*47,  p. 

68,  n",,  (  Juildin;:.—  JA<//'</'  rm  sect,  f,  GI:AY,  (iuide,  p.  184,  1857.  — 
fopk  ura  ADS.  et  a/.,  non  SHI-TTI.W. 

Valves  entirely  exposed,  smoothish,  laekin--  eyes  ;  IDIKTO  flat  :  the 
sutural  plates  broad  and  connected  across  the  sinus  ;  insertion-plate- 
of  all  valves  blunt,  closely  and  deeply  cleft,  the  median  valves  with 
3  or  4,  end  valves  with  many  >hort  slits.  Girdle  leathery,  setose. 
(iills  extendini:  the  entire  length  of  tin-  : 

The  valves,  when  eroded,  are  seen  under  the  len>  t«.  be  «lnisely. 
evenly  and  regularly  punctured  all  over.  The  interior  is  white,  and 


i  IIM.X.H  m  i 

<•('  a    dense,    porcellanuu>    texture.     The    laciniated    inMltk>n*p] 
cut  into  many  short  teeth,  combined    with    the   haohh  mile 

and  continuous  sut  ural-plate>,  an-  the  nio>t    >t  rikinir    Lreiierir    diar- 

acten, 

From  A<'<inflx>}>/i  urn  and  Mau^i-rin,  irroups  to  which  Home 
authors  have  referred  the  type  of  this  ircnus,  Kml<,.n,rliifoi,  is 
sundered  by  the  lack  of  eyes  in  the  valves,  the  multiplicity  of  .-lit-, 
dcpres-cd  inucro,  etc. 

I',  sides  the  following,  C/i.  /inter  (CLem.)  Reeve  may  belong  to 
this  genus,  but  its  generic  characters  are  entirely  unknown.  See 
appendix. 

I-:.  eroBiua  (Jray.    PL  46,  figs.  88-95. 

Shell  ohlon.ir,  <  /<  r<itr<l,  the  valves  well  arched,  and  very  obtusely 
angular  on  the  dorsal  ridge,  side-slopes  convex.  Color  uniform  dark 
brown,  a  little  mottled  toward  the  beaks,  and  marked  with  scarlet 
there  ;  girdle  rusty-brown. 

Valves  broadly  A-shaped,  not  beaked,  the  lateral  areas  moder- 
ately raised,  smooth  except  for  the  microscopic  granulation  and  a 
few  excessively  indistinct  radii.  Central  areas  having  indistinct 
growth-lines.  Posterior  valve  (figs.  92,  Q3,  94)  elevated  in  front,  the 
mucro  flat,  central  ;  posterior  margin  gently  emarginate  behind. 

Interior  porcelain-white,  immaculate  ;  smooth  and  poreless. 
Sutural  plates  squared,  continuous  across  the  sinus,  which  is  indicated 
by  a  median  bay  or  notch.  Insertion-plates  having  broad,  blunt 
edges,  irregularly  and  deeply  pectinated,  and  having  in  the  head- 
valve  30,  median  valves  3-4,  tail-  valve  24-25  short  slits.  Eaves 
very  narrow,  deeply  grooved  along  the  teeth  and  slightly  spongy 
there. 

(iirdlc(fig.  95)  leathery,  rust-colored,  bearing  short  rigid  bl<n-k 
spinelets.     Length  60,  breadth  35  mill.  ;  divergence  100°-110°. 
,   Cnvk*'  Sfntif  ;   Martin'*  Jinii.  X*  »• 


Acctnthqpleura  >/oA///V  (  ii;  \v.  in  Dieffenbach's  New  Zealand,  ii,  p 

i  1843).  —  Chiton  (Einlu-nrl,it,m')  m>/n'li*  Gray,  SHUTTLW..  l>orn. 

Mittheil.  1*.~)3,  p.  67.  —  Chitn,,  t  Ch&tcpleura)   iinbili*  (\\-\\\,  SMITH, 

Zool.  Erebus  and  Terror,  p.  4,  t.  1,  f.  8  (1874  >.—  HuTTON,  Man.  N. 

/.  Moll.,  p.  115  (1880.) 

This  species  differs  from  the  following  in  its  more  elongated  and 

much  more  elevated    contour,   and   in    the   stronger   valves.     The 
13 


I'.il  TONK'IA. 

seventh  valve  is  represented  in  figs.  89,  90;  and  a  square  millimeter 
of  the  girdle  is  indicated  in  fig.  95. 

K.  nt  ri MM  Pilsbry,  n.  sp.     PI.  46,  figs.  96-100. 

Shell  oval,  <l>  j>, •<*.•<>  <f,  with  convex  side-slopes.  Color  dark  brown, 
the  girdle  greenish-brown.  Valves  broadly  A-shaped,  not  beaked, 
rounded  at  the  ends  ;  the  lateral  areas  well  raised.  Entire  surface 
smooth  except  for  a  microscopic  punctulation  and  slight  growth- 
lines.  Posterior  valve  (figs.  98,  99)  depressed,  the  mucro  plane, 
central ;  posterior  margin  hardly  marginate. 

Interior  white,  smooth.  Sutural  plates  continuous  across  the 
sinus  which  is  indicated  by  a  shallow  wave  or  bay.  Insertion- 
plates  blunt,  deeply  pectinated,  the  anterior  valve  having  17,  central 
3,  posterior  19  short  slits.  Eaves  very  narrow  and  grooved  along 
the  teeth. 

Girdle  leathery,  bearing  numerous  short,  rigid,  dark  brown  spine- 
lets.  Length  50,  breadth  34  mill. ;  divergence  135°-140°. 

New  Zealand. 

This  species  is  closely  allied  to  E.  nobilis,  from  which  it  differs  in 
the  proportions  of  the  valves,  depressed  form,  fewer  slits,  etc.  The 
seventh  valve  is  represented  in  figs.  96,  100.  The  specimen 
illustrated  was  sent  me  by  Professor  Hutton. 

Genus  XIV.     TONICIA  Gray,  1847. 

Tonicia  GRAY,  P.  Z.  S.  1847,  p.  65,  67;  Guide  Syst.  Dist.  Moll. 
B.  M.,  p.  185  (1857),  and  of  authors. — Probably  Tonichia  Gi;  \  g, 
Synops.  Contents  B.  M.,  42d  edit.,  p.  153,  1840  (name  only.) 

Generic  characters. — Valves  external,  all  having  pectinated  inser- 
tion-teeth ;  sinus  denticulate ;  lateral  areas  and  end  valves  bearing 
radiating  rows  or  bands  of  eye-dots.  Girdle  leathery,  naked  or 
sparsely  hairy.  Gills  extending  the  whole  length  of  the  foot. 
Type  C.  elegant  Frembly. 

l'>  -ides  the  fundamental  characters  above  recounted,  the  species 
of  this  genus  mostly  agree  in  having  the  valves  >mo7»this.h,  the 
second  valve  notably  larger  than  the  following  five,  and  often  differ- 
ently sculptured  on  the  ridge;  the  sculpture  is  generally  fine  or 
minute,  the  colors  much  variegated  or  uniform  black-brown,  and  the 
••s  are  hardly  spongy. 

IVom  CkcRtopleura  and  T<m'n-e1ln  this  ireim-  is  verv  strongly 
differentiated  by  the  presence  of  eyes,  and  also  by  the  more  distiix  tly 


i .  i  \ .  1  !)."> 

pectinated    insertion-plates.      Tin-    .u'emis    ( hiil hodiihni     ha~    nmilar 
>iii'M»t!i     valve-,    !»iit    the    posterior    valve    lacks    slits    and    teeth    of 

insertion, 

The  specie-  «>f  Tnu'n'in  iuhahit   mainly   the  -hores  of  the  southern 
and  tropical    Pacific,  hcin.u;   found    from    Middle    America    lo   < 
Horn,   and    irom    tin-    Philippines  to  Australia   and   New   Zealand. 
They  may  l>e  grouped  thus: 

A.  Valves  not  immersed  or  separated,  imbricating,  section   Tonicia. 

1.  Species  of  West  America. 

2.  Species  of  the  Wc.-t  Indies. 

3.  Species  of  New  /ealand,  Australia,  Red  Sea,  Philippines. 

B.  Valves  partly  separated,  the  girdle  encroaching  on  them  at  the 

sutures,  section  Fannettia. 


Section  Tonicia  s.  sir. 
I.  Species  of  West  American  shores. 

T.  CRENULATA  Sowerby.     PL  45,  figs.  69,  70,  71,  72. 

Shell  oblong-ovate,  slightly  more  narrowed  in  front,  moderately 
raised,  the  back  carinated.  Ground-color  buff  or  slightly  rose- 
tinged,  having  oblique  dark  olive  irregular  stripes,  often  marked  on 
some  valves  with  rich  brown  ;  apices  of  valves  pink  when  eroded. 

The  lateral  areas  are  raised  and  well-defined,  and  except  the  pos- 
terior third  or  fourth,  are  studded  closely  with  black  eyes;  the  suture 
is  prominently  ami  ro'iwly  '-renulated,  and  there  are  some  irregular 
radiating  rows  of  granules  on  the  back  part  of  the  areas,  and  some- 
times a  row  or  two  dividing  the^eye  tract.  Central  areas  having  a 
smooth  keel  in  the  middle,  bounded  on  each  ru/re  by  a  V  formed  by 
two  low  divergent  waves,  crossed  by  convergent  riblets ;  pleura  or  sides 
sculptured  with  longitudinal-diverging  rugte  or  ribs.  Anterior 
valve  high,  with  radiating  rows  of  weak  granules  alternating  with 
rays  crowded  with  eyes.  Tail  valve  with  slightly  posterior,  elevated 
mucro. 

Interior  white,  with  a  large  red  tract  in  each  of  the  median  valves. 
Slits  in  anterior  valve  s,  central  1,  posterior  14;  teeth  obtuse  and 
short  in  the  posterior,  acute  and  longer  in  the  anterior  valves,  sulcate 


196 

"in side  and  at  edge.  Sinus  square,  denticulate  ;  sutural-plates  ami 
in>t  rtiun-plates  white. 

Girdle  leathery,  thin,  yellowish-green,  naked. 

Length  34,  breadth  20  mill. 

Length  50,  breadth  33  mill. ;  divergence  115°. 

J'enrl  Island,  Bay  of  Panama  (Cuming,  et  al) ;  Mazatlan 
(Reigen.) 

Chiton  crenulatus  BROD.,  P.  Z.  S.  1832,  p.  27.— SOWERBY,  Conch. 
Illustr.,  f.  43.— REEVE,  Conch.  Icon.,  no.  29,  t'.  6,  f.  39  (error  for  29). 
"/  Tonicia"  forbesii  CPR.,  Mazatlan  Catal.,  p.  193  (1856.) 

This  species  is  readily  distinguished  from  the  other  West  Amer- 
ican forms  by  the  greater  width  of  the  lateral  bands  of  eyes,  the 
crenulated  sutures,  and  the  beautiful  sculpture  of  the  central  areas. 
The  second  valve  is  not  so  prominent  as  in  most  species  of  Tonicia, 
and  it  is  sculptured  like  the  other  intermediate  valves. 

T.  ELEGANS  Frembly.      PL  41,  figs.  22,  23,  24 ;  pi.  42,  figs.  31,  32, 

33,  34,  35. 

Shell  elliptical-oblong,  not  much  elevated,  the  dorsal  ridge 
rounded,  side-slopes  straightened.  Color  umber-brown  at  the  sides, 
becoming  chestnut  in  the  middle,  delicately  and  peculiarly  speckled 
and  blotched  and  streaked  with  buff  or  buff-white. 

Lateral  areas  hardly  raised,  but  separated  from  the  central  areas 
by  an  obtuse  diagonal  ridge  bearing  a  series  of  low  tubercles,  some- 
times subobsolete  ;  sculptural  n'ith  subradiating  roics  of  small  gran- 
ules, and  showing  a  band  of  irregularly  placed  black  eyes  on  the  for- 
ward part.  Central  area  of  second  valve  having  in  the  middle,  a 
keel  or  a  group  of  line ;  centralareas  of  the  other  rntrrs  hiring  a  i\«r- 
<Dwoth  dorsal  band  with  several  longitudinal  furrows  on  each  side 
of  if ;  and  at  the  sides  there  are  longitudinal  diverging  delicate  rows 
of  granules.  End  valves  radially  subgranulate,  and  crowded  with 
eye-spots  subradially  arranged.  Mucro  in  front  of  the  middle, 
moderately  elevated. 

Interior  porcelain  white,  with  a  spot  or  "  V"  of  red-brown  under 
the  beak  of  each  valve.  Sinus  flat,  distinctly  but  finely  denticulate. 
Slits  short,  in  the  anterior  valve  8,  in  the  central  1,  in  the  posterior 
valve  '.'  1 '_'  :  teeth  blunt,  lonir  and  very  finely,  deeply  pectinated  out- 
side; slit-rays  regularly  puneticulate. 

(lirdlr  naked,  leathery,  of  a  rhe>tnut-yellow  color. 

Length  48, breadth  '\'2  mill.;  divergence  125°. 

Call <tn  f<>  Valparaiso. 


[CIA,  l'»7 

n  '  FBXKBLY,  ZooL  .i<>un>.  ill,  p.  208,  -nppl.,  pi.  17,  f. 

6. — S.  >\\  r...  ( 'oiich.  Illuslr..  no.  75,      II  i.i.v  i  ,  (  ouch.  Icon.,  t.   I.  f.  11). 
—  ('.  3OWB.J  Conch.  IllnMr.,  f.  7-'),  7  \  'young.) 

The  type  species  of  T"iii<-in.  The  scul ptu re  is  well  shown  in  fi;:. 
1)%J  :  the  color-pattern  in  the  liirure  l>ct\\ccn  '2'2  and  lM. 

Subspecies  cnii.i  N-I-  Fremhly.     PI.  41,  figs.  19,  20. 

Shell  rather  heavier  and  thicker  than  T.  rlgr/an*,  with  thicker 
girdle.  G>A>r  «  uniform  tlnrk  chocolate  brown,  except  near  the  beaks 
n'here  ff»  re  /.<  a  large  or  sum//  arm  th<  *hnj>r  of  f/ir  ra/rr  n-hich  is 
/i'/hf  de/irnfe/it  mnff/><l  irith  r<'<1ai«li  ;  girdle  dark  brown,  wide  at  the 
sides,  narrow  at  the  ends. 

Th>  tlingtinul  litir  /x  turmounted  by  a  wie*  <>f  #wnll  tubercle; 
lateral  areas  showing  fewer  and  less  conspicuous  eye-spots  than  T. 
el''</(iu*i  and  otherwise  ?}/•///•///  xnumfli,  flu-  t/r<niul<ition  being  obsolete ; 
central  areas  striated  on  each  side  of  a  median  smooth  band,  and 
more  or  less  (variously)  roughened  at  the  sides  ;  second  valve  sub- 
carinate,  striated  in  the  middle.  End  valves  radially,  sparsely 
granulate  and  dotted  with  eyes,  the  umbo  of  the  tail  valve  obtuse, 
conspicuous,  elevated,  a  little  in  front  of  the  middle. 

Interior  white,  marked  with  reddish  under  the  beaks.  Sinus 
toothed.  Sutural  plates  broad,  especially  at  the  outer-anterior  portion . 
Anterior  valve  having  7,  central  valves  1,  posterior  valve  8  slits; 
t>  >  th  r>  /•'/  thick  and  b/tmt,  strongly,  closely  pectinated. 

Girdle  leathery,  naked,  rather  thick. 

Length  38,  breadth  28  mill.;  divergence  130°. 

Length  68,  breadth  43  mill. 

Valparaiso,  under  stones. 

C.  r/iit''n.«I*  FREMB.,  Zool.  Journ.  iii,  p.  204,  suppl.,  pi.  17,  f.  8. — 
REEVE,  Conch.  Icon.,  t.  3,  f.  17. —  Tonicia  chilenxis  ROCHEBRUNE, 
Nouv.  Arch,  du  Mus.  1881,  p.  240  (Reported  from  the  Canaries,  on 
the  authority  of  specimens  so  labelled  in  the  Paris  Museum,  but 
undoubtedly  false.) 

This  form  is  very  closely  allied  to  T.  elegans,  differing  mainly  in 
the  (a)  dissimilar  coloration,  (/>)  more  numerous  stria?  on  each  side 
of  the  median  smooth  band,  (c)  generally  obsolete  granulation  of  the 
lateral  areas,  (d)  thicker  insertion-teeth,  and  in  the  thicker  girdle  ; 
a  still  better  distinction  is  in  the  tail-valve,  which  in  rh Mentis  has  a 
more  prominent  umbo,  nearer  the  center  than  in  <  /ff/ans,  and  the  area 
in  front  of  the  umbo  is  striated,  whilst  in  rlei/nn*  it  is  smooth.  All 


198  TONKIA. 

of  these  differences  however,  do  not  avail  to  name  specimen-  in 
which  various  characters  of  eZ^an*  are  combined  with  other  char- 
acters of  cliilni.*!*  ;  so  that  while  when  typically  developed  the  forms 
may  readily  be  separated,  it  is,  I  believe,  impossible  to  classify 
occasional  synthetic  specimens.  I  have  therefore  considered  <-h  if- 
a  phase  or  variety  of  d>  </////*. 

Subspecies  LINEOLATA  Frembly.     PL  41,  figs.  25,  26,  L'7. 

Shell  oblong,  moderately  raised,  the  ridge  rather  rounded.  Sur- 
face smoothish.  Ground  color  light  fawn  or  fleshy,  each  valve 
close/;/  and  finely  lineolate  with  chestnut,  the  lines  concentric  to  the 
umbones ;  fifth  valve  marked  with  brown  at  the  ridge,  and  often 
some  of  the  other  valves  are  marked  with  dark  brown  or  are  entirely 
of  that  color. 

L>il<i-af  areas  closely,  finely  granulated,  and  having  two  or  three 
rows  of  eyes  extending  down  near  the  low,  smooth  diagonal.  Central 
areas  smooth  except  for  a  group  of  engraved  grooves  on  each  side  of 
the  smooth  narron-  (hr*al  bawl.  Second  valve  either  smooth  or  hav- 
ing a  median  carina.  End  valves  granulate  toward  the  periphery, 
closely  dotted  with  eyes  in  irregularly  radiating  rows.  Urn  bo  of 
tail  valve  anterior,  the  space  in  front  of  it  smooth. ' 

Inside  white,  each  valve  marked  with  reddish  under  the  beaks. 
Sinus  delicately  denticulate.  Anterior  valve  having  8-9,  central  1, 
posterior  valve  9-10  slits;  teeth  blunt,  pectinated. 

Girdle  leathery,  nude,  yellowish-brown. 

Length  25,  breadth  15  mill.;  divergence  110°. 

Length  40,  breadth  23  mill. 

Valparaiso,  Ch  ill. 

Chit»)i  linfolatus  FREMBLY,  Zool.  Journ.  iii,  p.  L'i'4.  suppl.,  pi.  17, 
f.  7  (Good). — SOWERBY,  Conch.  Illustr.  (as  syn.  of  elegant),  f.  1  ">-l. 
—  KI.KVK,  Conch.  Icon.,  t.  7,  f.  34. —  Tmtinu  Hn<>>i/afn$  CPU. — 
?  Chitm,  bruguieri  I'ot.  &  Mich.  Galerie,  i,  p.  534  (1838.) 

The  distinguishing  characters  of  typical  lineolatu."  are  the  lack  of 
larger  tubercles  along  the  diagonal  rid-v.  and  the  fine  concentric 
line-painting.  The  characters  of  both  sculpture  and  color-pattern 
however,  are  in  some  specimens  inextricably  united  with  these  of  T. 
elegan-,  of  which  species  I  am  therefore  compelled  to  consider  this  a 
variety. 

Many  specimens  show  several  valve-  of  uniform  black-brown; 
others  are  blotched  on  many  valves  with  the  same.  The  species 


[OTA,  I'1-' 


somewhat  resembl<  '/<i  /inea/o  Wood  (><•<•  p.   H',  pi.  11. 

(8),   lull    dilli-rs   sufficiently    in    sculpture   and    tli-  OH  <>f 

black  eye-pits,  as  well  as  in  tin-  entirely  diilJ-mit   insertion-p 

/'.  *  nihles    /uii'n/tifii    in    color-pattern,    l»nt    it    dilfer- 

entirely  in  having  the  entire   central   areas   Inngit  udinally,  and   the 
latei-il  areas  and  end  valves  radially  c-ostuhite. 

T.  i  AMI..IM  v     (.r;iv     Sowe.-l.y.     PI.  41,  fig.  21  ;  pi.  4L>,  figs.  36, 

37,  38, 

Shell  oblong,  moderately  elevated,  subcarinated  ;  the  side-slopes 
nearly  straight;  surface  sinoothisli.  Color  olive-brown,  sometimes 
whitish,  Inirl  IK/  imli^lnd  concentric  dur/a  r  xtre'tk*  ;  rarely  unicolored 
black-brown. 

/  teral  urea*  hai-dlij  raised,  indistinctly  separated  from  the  central 
areas  by  a  smooth,  low  or  obsolete  diagonal  ridge.  Entire  surface 
of  lateral  and  central  areat  covered  with  a  microscopic  granulation, 
the  granules  sometimes  coalescing  into  short  wrinkles  in  front  of  the 
diagonal  at  the  sides.  7)o/W  ridyr  Imvlmj  a  i'cnj  narrow  .-•niootk 
band  in  the  middle,  on  each  *ide  of  whic.lt  fhrre  are  several  deeply 
engraved  longitudinal  <froov<'.-<.  Second  valve  either  smooth  or 
having  a  group  of  striie  in  the  middle.  End  valves  showing  numer- 
ous rays  of  eyes  ;  the  mucro  of  the  posterior  valve  prominent,  in 
front  of  the  middle. 

Interior  white,  marked  under  the  apex  or  suffused  throughout  the 
jugal  tract  with  reddish.  Sinus  toothed.  Anterior  valve  having  7, 
central  1,  posterior  valve  10  slits;  teeth  rather  thin,  crenulated  out- 
side and  at  the  edge. 

Girdle  leathery,  nude,  dark  brown. 

Length  54,  breadth  'U  mill.  ;  divergence  110°. 

Length  48,  breadth  26  mill.;  divergence  110°. 

.  of  Mut/t  linn. 

C.fagtigiatui  GRAY,  inSowB.,  Conchol.  I  llustr.,  t'.  11,  35.  —  REI 
Conch.  Icon.,  f.  26.—  SMITH,  P.  Z.  S.  1881,  p.  35. 


ohiloensi*  Sown.,  }>.  Z.  S.  ls:v_>,  p.  58;  Conch.  111.  (assyn. 
of  elegant),  f.  18*,  10,  29,  30.—  RKEVK,  Conch.  Icon.,  t.  3,  f.  14. 

The  main  distinguishing  characters  of  this  species  are  its  even  fine 
granulation,  lack  of  tubercles  on  the  low  diagonal  ridge,  few 
engraved  grooves  on  each  side  of  the  smooth  narrow  dorsal  baud, 
and  the  obscure  concentrically  streaked  style  of  coloration. 


200  i "  M  i  •  i  A  . 

I  do  not  know  whether  the  C.clnlornsis  of  Sowerby  belongs  to  this 
species  or  to  C.  elegans.  It  is  represented  on  pi.  42,  fig.  40. 

T.  GRANIFERA  Sowerby.     PL  43,  figs.  44,  45. 

Shell  ovate,  chestnut  varied  with  white  and  black;  dorsum 
elevated ;  front  valve  radially  granose  ;  lateral  areas  and  posterior 
area  of  posterior  valve  subradiately  graniferous;  central  areas 
longitudinally  granose-lineate,  marginal  ligament  smooth. 

Length  25,  breadth  15  mill.     (&w-&.) 

Conception,  Chili;  on  Mytilus  in  9  fms.     (Cuming.) 

C.  graniferus  SOWB.,  P.  Z.  S.  1832,  p.  104  (Conch.  111.,  f.  8  ?).— 
KEEVE,  Conch.  Icon.,  t.  15,  f.  86. —  ToniciayraniferaGpR.,  MS. 

Evidently  closely  allied  to  T.  elcf/an*,  having  much  the  same 
sculpture. 

T.  GRAYI  Sowerby.     PI.  43,  figs.  46,  47. 

Shell  oblong,  pale,  varied  with  brown  and  rufous ;  anterior  vnlrr, 
lateral  areas  and  tail  valve  radially  granose-striate ;  anterior  margins 
of  lateral  areas  elevated,  posterior  margins  [xutures]  crcnulated. 
Central  areas  obliquely  longitudinally  granulose-striate ;  third  to 
ft  i-i-nth  valres  longitudinally  bixulcate  in  the  middle.  Marginal 
ligament  smooth.  Length  30,  breadth  17 \  mill.  (&»/•/>.) 

Island  of  St.  Lawrence,  Bay  of  Callao,  Peru,  on  shells  in  17  fms. 
(Cuming.) 

Chiton  f/raifii  SOWB.,  P.  Z.  S.  1832,  p.  57  ;  Conch.  Illustr.  f.  8.— 
REEVE,  Conch.  Icon.,  t.  17,  f.  105. —  Tonicia  grayi  CPR.,  MS. 

This  form  is  evidently  closely  allied  to  T.  elegan*,  etc.  The 
italics  of  Sowerby's  description  translated  above  are  my  own. 

Carpenter  thus  describes  the  type  specimens  :  Jugular  areas  with 
deep  grooves  on  each  side  of  the  central  smooth  rib,  but  both  grooves 
and  rib  are  evanescent  on  the  second  valve.  Central  areas  with  a 
second  set  of  granules  parallel  to  the  diagonal  and  more  or  less  con- 
tinued into  faint  riblets,  somewhat  diverging  from  the  more  prom- 
inent apices.  Lateral  areas  with  a  very  decided  row  of  rugose 
granulations  along  the  diagonal,  inside  of  which  is  a  smooth  space 
crowded  with  metallic  dots  [eyes] ;  then  two  or  more  rows  of  very 
rough  irregular  granules,  ending  in  sharply  crenate  sutures.  End 
valves  with  about  eleven  obsolete  riblets,  irregularly  Lrranosc,  with 
rows  of  metallic  dots  between  each.  Mucro  in  front  of  the  middle, 
swolk-n,  but  the  slope  behind  it  Anterior  valve  having  8 


central     I,     po.Mrrior    valve    II    slils;    treth    v«-rv    .-harp,    !"•<•!  inat«-d 
Sinus  Hat  moderately  deep  and  hn»ad,  \\ith  up  to  Hi  teeth. 

Lengtli  80,  hreadth  17  mill.;  divei 

T,    MKMA  Sowerl.v.      IM.   II.  ftgi,  28,  I".),  30. 

Shell  oval-oblong.   smooth,    sulicarinated  ;    valve-    ncarlv 
sul.n»trate  ;   lateral  areas  inconspicuous;   maririn  ['_rmlle]  smooth. 

Length  26,  breadth   1  L'.1.  mill.       \o,r/,.) 

The  smooth,  narrow,  .-lightly  aiiLrulated  species  above  de-rrib« 
of  a    blackish-brown    color;  the   lateral   areas   an-    not    distinctly 
marked  except  l>y  rays  ot'liirhtcr  color  in  some  specimen-  on   them, 
and  on  the  terminal  valve>.     (.sVw/>.) 

F'tlL-tnnd  I*.  (Sowb.)  ;    Ora),<f    7/./rW  (U.  S.  Ex.  Exped.) 

Chit  nn  nti-nttt  Sowu.  in  Charlesworth's  Magazine  of  Nat.  Hi-t. 
1840,  p.  294  ;  Conch.  Illustr.,  f.  57,  58.—  REEVE,  Conch.  Icon.,  t.  1  7, 
f.  103.—  GOULD,  U.  S.  Kxpl.  Kxped.,  p.  329,  f.  415.—  7  o//  //•/,/  ntrata 
H.  ct  A.  ADS.,  Gen.  Kec.  Moll,  i,  p.  474.  —  ROCHKHIIUNK,  I'olyplac. 
Cap  Horn,  p.  138.—  T7.  bcetica  CPR.,  3/N.  <,lim. 

I  have  not  seen  this  species.  Carpenter  writes:  Mucro  more  or 
less  elevated,  tumid  behind.  Inside  having  8  slits  in  the  anterior, 
1  in  the  middle  and  12  in  the  posterior  valve;  teeth  acute,  outside 
and  at  the  edge  silicate,  scarcely  pectinated;  sinus  moderate,  Hat, 
with  i:>-20  denticle-. 

Hutton  reports  this  species  from  Macquarie  Island,  X.  /.,  but 
says:  "  Our  species  agrees  very  well  with  Reeve's  figure,  but  not 
with  hi.s  description.  The  anterior  terminal  area  is  distantly 
radiately  ribbed,  and  the  lateral  areas  are  sometimes  defined  by  a 
single  rib.  The  umbone  of  the  posterior  valve  is  more  posterior 
than  in  the  drawing,  and  the  valves  are  of  a  uniform  hrown  color. 
The  mantle  is  of  the  same  color  as  the  valves."  These  characters 
seem  to  me  to  indicate  a  distinct  species,  which  may  he  called 
/'// 


T.  SWAINSONI  Sowerby.     PI.  43,  figs.  41,  42.  43, 

Shell  oval,  moderately  or  decidedly  elevated,  somewhat  earinated. 
the  side-slopes  nearly  straight.  <  I  round-color  li^ht  pinki>h-l>uH'. 
/minted  all  over  with  n  mult  if  ml-  r  rrtl-hroivn  linen,  < 

t»  the  beaks;  often  havinir  some  valves  striped  at  or  on  each  side  of 
the   ridire,  or  more  or  le>s  completely  covered  with  dark  n-d-l»ro\\n. 

Lateral   areas    little    raised,   xo////^,>'</    "•/'///    ufn,,,t    s 


202  TONICIA. 


the  riblets  sometimes  broken  into  rows  of  distinct  granule.*. 
Central  areas  lonr/iti«lin<t//i/  codnlnte  except  for  a  narrow,  smooth 
dorsal  band  on  the  latter  6  valves.  End  valves  radially  ribbed, 
with  rows  of  eyes  in  the  intervals.  Umbo  of  tail  valve  anterior, 
elevated. 

Interior  white,  some  or  all  of  the  valves  having  a  small  reddish 
spot  under  the  apices.  Sinus  narrow,  denticulate.  Anterior  valve 
having  8,  central  1,  posterior  valve  10-12  slits;  teeth  pectinated. 

Girdle  yellow  or  brown,  leathery,  thin. 

Length  34,  breadth  20  mill.;  divergence  100°-110°. 

Callao,  Peru. 

WMontt  SOWB.,  P.  Z.  S.  1832,  p.  27  ;  Conch.  Illustr.,  f.  5.— 
REEVE,  Conch.  Icon.,  t.  7,  f.  38.  —  Lophyru*  swainsonii  TAP.-CAN. 
Viag.  Magenta,  p.  75. 

This  species  is  well  differentiated  from  forms  of  the  elegans  group, 
by  the  longitudinal  ribbing  of  the  entire  central  areas.  The  ribs 
vary  much  in  prominence,  however,  and  in  many  individuals  the 
riblets  of  the  lateral  areas  are  broken  into  granules.  The  color- 
pattern  is  similar  to  that  of  T.  lineolata,  but  finer. 

T.  RUBRIDENS  Pilsbry,  n.  sp.     PL  44,  figs.  65,  66,  67. 

Shell  oblong,  elevated,  the  dorsal  ridge  roundly  angular,  side- 
slopes  straight.  Surface  smooth.  Tawny-brown,  sometimes  uni- 
colored,  but  generally  having  dotted  light  rays  on  lateral  areas  and 
end  valves,  and  a  dark  dorsal  band.  A  light  fawn  color  sometimes 
predominates  over  the  dark. 

Valves  rounded  at  the  front  corners,  moderately  beaked  ;  sutures 
not  crenulated. 

Lateral  areas  not  perceptibly  raised  (except  on  the  second  valve), 
sculptured  with  minute,  i/i'iinu/r*  npnwhj  nml  irn  </"/"/•/'/  .*nitfi  /•«/, 
varying  much  in  number;  and  along  the  forward  part  there  is  MM 
series  of  *mall  black  eye-dots,  becoming  an  irregularly  double  series 
on  the  lower  half  of  the  slope.  End  valves  weakly  Lrranulose  and 
having  radiating  rows  of  eyes.  (  '<  at  ml  an  </.«  '  /////•<  ///  *uinnfh  e.rr,/,! 
fur  growth-line*,  huviny  no  ijrnoi'i*  (i/o/iij  fftt-  tli,r*nl  ri<l<j>  .  Beak  of 
tail-valve  obtuse,  behhul  il<  miililfc. 

Inf<  n'or  of  a  jie'-u/inr  r»l-/>roirn  color,  the  callus  of  each  valve- 
whitish.  Siittirii/'ii/nfi.«  //////,  )'til-l»rnirn.  Sinus  delicately  dentic- 
ulate. the  area  behind  it,  extending  to  the  beak,  transversely 
wrinkled.  Slit<  in  anterior  valve  8,  central  valves  1  .  posterior  valve 


'I  . 


roinci  \. 

teeth  finely  crenulated  oiilsidr  ami  at  ed'je,  rather  thin,  and 
colored  ivd.  A-  in  other  -prrirs  liavini:  a  po-h-rior  mncro,  the  tail- 
valve  teeth  art-  directed  forward. 

<  iirdlr  yellowish,  leathery,  nude  and  smooth. 

Length  L'*,  luvadth   1 :»  mill.;  divergence  108°. 

Callao ;  and  Chili  (U.  S.  1 

This  species  differs  from  all  of  the  T.  vtcgans  group  in  lacking 
sculpture  upon  the  central  areas  and  engraved  grooves  along  tin- 
dorsal  ridge;  and  from  other  species  of  Toniria  in  the  red  sutural- 
platcs.  teeth,  etc.  The  blunt  inucro  is  posterior,  and  the  teeth  in  the 
tail-valve  are  directed  forward.  The  posterior  margin  of  the  tail 
valve  is  broadly  waved  upward  in  the  middle,  as  in  Eudoxochiton. 

T.  HORNIANA  Rochebrune.     PL  43,  figs.  50,  51. 

Shell  ovate-elliptical,  carinated,  rufous,  marbled  with  buff  and 
roseate ;  anterior  valve  radially  costate,  posterior  valve  small ;  inter- 
mediate valves  having  the  central  areas  minutely  concentrically 
striated;  lateral  areas  multi-sulcate  and  ornamented  with  two  lines 
of  dots.  Marginal  ligament  dull  roseate. 

Length  19,  breadth  14  mill.     (Eochebr.') 

Orange  Bay,  Patagonia. 

T.  horniana  ROCHEBR.,  Polyplac.  Cap  Horn,  p.  139,  t.  9.  f.  7. 

T.  M  ARTIELI  Rochebrune.     PL  43,  figs.  48,  49. 

Shell  ovate-elongate,  strongly  carinated,  the  ends  of  the  valves 
curved  backward,  brown-rose,  anterior  valve  radially  strongly 
costate ;  posterior  valve  small ;  intermediate  valves  having  the 
central  areas  transversely  lineated,  lines  denticulate;  lateral  areas 
granulated  and  margined  by  asquamate  hand.  Marginal  ligament 
violaceous-rufescent.  Length  21,  breadth  14  mill. 

Strait*  <>f  Miiyltitn. 

T.martieli  ROCIIKHK.,  Polyplac.  Cap  Horn,  p.  i:J!»,  t.  9,  f.  8 
(1889.) 

T.  LI.HKUNI  Rochebrune.     PL  43,  figs.  52,  53. 

Shell  ovate-elliptical,  carinated,  shining,  violaceous  or  greenish- 
roseate.  End  valves  radially  most  minutely  striated;  intermediate 
valves  having  the  lateral  areas  covered  with  tubercles  ;  the  central 
areas  concentrically  silicate,  the  sulci  wavy;  marginal  ligament 
narrow,  leathery,  whitish- violaceous. 

Length  29,  breadth  12  mill.     (AV//e6r.) 

Punta  Arenas,  0 ran y    /:    .  >';. /•/' .1A/;// //»//». 


•J'»J  -I  CIA. 

Touiria  lebnnii  ROCH.,  Bull.  Soc.  Philomath.  Paris,  1883-'84,  p. 
35 ;  Polyplac.  Cap  Horn,  p.  138,  t.  9,  f.  6. 

T.  FONTAINKI  Rochebrune.     Unfigttred. 

Shell  ovate,  broad,  subcarinated,  gray,  with  brown  spots.  Ante- 
rior valve,  lateral  areas  of  intermediate  valves,  and  posterior  part  of 
posterior  valve  very  delicately  striatulate  and  sparsely  covered  with 
conic  tubercles  ;  central  areas  sculptured  with  beaded  longitudinal 
waved  lines.  Marginal  ligament  rather  wide,  leathery,  rufous. 

Length  11,  breadth  9  mill.     (Rochebr.} 

Chili  (M.  Fontaine)  ;  Paris  Museum. 

Tonicia  fontainei  ROCHEBR.,  Bull.  Soc.  Philom.  de  Paris,  1881- 
1882,  p.  193. 

The  foregoing  species  are  not  defined  with  sufficient  exactness  to 
insure  their  indentification,  Rochebrune  being  a  century  behind  the 
times  in  descriptive  zoology. 

T.  ARGYROSTICTA  Philippi.     Unfigured. 

Girdle  smooth.  Valves  smooth,  subcarinated ;  lateral  areas  hav- 
ing a  single  series  of  distinct  silvery  impressed  dots. 

Length  4J,  breadth  3  lines. 

This  small  species  is  sufficiently  distinguished  by  the  peculiar 
impressed  silvery -shining  points,  which  remind  one  of  the  similar 
marking  on  some  Carabidse.  On  both  end  valves  they  stand  in 
several  concentric  rows.  The  coloring  varies  ;  the  brown-red  color 
predominating;  in  one  example  there  are  whitish  flecks  and  trans- 
verse stripes,  in  another  longitudinal  stripes.  (Phil.') 

Strait*  <>f  Muyellun. 

Chiton  argyrostictus  PHIL.,  Archiv  fur  Naturg.  1845,  p.  59. 

T  /.SCHAUI  Pfeffer.     PI.  40,  fig.  12. 

The  animal  is  much  elongated,  the  breadth  hardly  one-half  the 
length.  The  inner  region  of  the  girdle  is  covered  with  very  minute 
granules,  hardly  visible  under  a  strong  lens,  arranged  in  not  entirely 
regular  oblique  series,  and  separated  by  about  their  own  dimensions. 
Under  a  low-power  lens  the  girdle  appears. quite  naked.  Toward 
the  margin  these  granules  grow  into  transparent,  short  spines.  The 
28  branchiu.'  roach  the  entire  length  of  the  foot. 

The  valves  are  quite  shining,  and  sculptured  with  close  growth- 
stria? ;  otherwise  they  appear  smooth  under  a  \\vak  power  of  the 
lens;  under  strong  magnification  a  fine  granulation  is  \i>il>lr.  The 
median  valves  have  only  a  low  angle  separatini:  central  and  lateral 


01  v. 

arras;   the  growth  wrinkles,  which  mi  the  lateral  U  and 

prominent,  are  Weaker  OD  the  central  areas,  the  posterior  part  of 
which  appear  sculptureless.  The  iimho  seem.-  to  \v  produced  hack- 
ward  [heakedj  in  young  shells,  hut  in  this  specimen  it  is  so  upon  the 
I'd  valve  only.  The  dorsal  ridge  is  bluntly  angular.  The  head 
valve  is  long  compared  with  its  hreadth,  the  length  of  the  front 
slope  equalling  tliat  of  each  of  the  posterior  margins  ;  it  shows  weak 
concentric  sculpturing  of  stria?.  Tlie  tail-valve  is  small  and  narrow, 
not  much  more  than  two-thirds  as  broad  as  the  head  valve,  and  also 
notably  shorter;  its  forward  area  is  not  shining;  the  posterior 
segment  is  shining  and  sculptured  like  the  head  valve. 

The  lateral  areas  and  the  outer  anterior  parts  of  the  central  areas 
are  yellowish-red  with  red  marbling.  The  central  area  shows  on 
its  middle  part,  a  group  of  beautiful  chocolate-brown  and  violet- 
white  stria?,  radially  diverging  from  the  umbo.  On  the  anterior 
median  valves  are  seen  also  a  few  clear  brown  streaks  on  the  outer 
part  of  the  central  areas. 

The  single  specimen  before  me  is  fastened  on  pasteboard,  and 
measures  13'5  by  6  mill.;  the  broadest  valve  is  5  mill.,  so  that  the 
girdle  is  but  *5  mill.,  wide.  The  third  median  valve  of  this  specimen 
is  abnormal  in  being  pure  white. 

South  Georgia. 

Chiton  zschaui  PFFR.  in  Moll.  Siid-Georgien,  Jahrb.  Hamb. 
Wissensch.  Anstalten  iii,  p.  105,  t.  3,  f.  2  (1886.) 

This  is  placed  in  Tonicia  with  much  doubt,  for  the  presence  of 
eyes  is  not  noted  in  Pfeffer's  description,  above. 

T.  TEHUELCHUS  d'Orbigny.     PI.  40,  figs.  13,  14,  15. 

Shell  oblong,  elevated,  strongly  carinated  ;  brown  with  two  white 
longitudinal  zones ;  head-valve  and  lateral  areas  radially  sulcate- 
bifurcate;  central  areas  longitudinally  punctate-silicate. 

Length  27  mill.     (Orb.) 

Jj<n/  i»i  Sun  lilni*,  Patagonia* 

Chiton  tehnelchus  ORB.,  Voy.  dans  I'Amer.  Merid.,  p.  488,  t.  i '»."». 
f.  7-13. 

The  sculpture  reminds  one  of  Chcetopleura  inlrn  Wood.  The 
generic  position  is  not  certain. 

2.    We*t  I it'll' in  species. 
T.  SCHKAMMI  Shuttleworth.     PI.  4:>,  figs.  r>4,  55,  56. 

Shell  oblong,  moderately  elevated,  roundly  angular.  Surface 
polished.  Qround-eolor  l>uj)\  mnitlt<l,  sp^-klcd  <>r  sometime* 


206  i  CIA. 

with  bright  rtddith-brown.  Valves  strongly  beaked,  the  umbo  of  the 
far  to  the  posterior  (fig.  54).  Central  area*  smooth 
throughout;  lab  ml  areas  separated  from  the  central  by  a  prom- 
inent, rounded,  curved  diagonal  rib,  and  #mo<»th  except  for  a  broad 
band  of  black  eye  dots,  variously  arranged,  on  the  forward  half; 
suture*  feebly  or  obsoUfaly  crenulated.  Head-valve  smooth  except 
for  8-10  broad  rays  of  eye-spots. 

Interior  white,  stained  with  crimson  along  the  jugal  tract.  Sinus 
obsoletely  denticulate.  Anterior  valve  having  9-10,  central  valves 
1,  posterior  valve  14  slits;  teeth  deeply  and  regularly  pectinated  on 
outer  face  and  edge.  Posterior  border  of  each  valve  in  flexed  and 
maculated  with  reddish. 

Girdle  leathery,  tawny,  flesh-colored. 

Guadalupe  ;  Florida  Keys  ;  Bermuda, 

Chiton  (Tonicia)  Mchrammi  SHUTTLW.,  Journ.  de  Conchyl.  1856, 
p.  171,  t.  6,  f.  9.  —  T.  schrammi  HEILPRIN,  The  Bermuda  Is.,  p.  176. 
BALL,  Catal.  Moll.  S.  E.  U.  S.,  p.  174. 

This  form  differs  markedly  from  those  of  Western  South  Amer- 
ica in  the  non-sculptured  central  areas,  prominent  diagonal  rib  (like 
that  of  T.  cremilata),  and  broad  bands  of  eye-spots.  The  umbo  of 
the  tail-valve  is  far  backward,  and  in  most  specimens  the  posterior 
margin  of  the  same  valve  is  distinctly  emarginate  in  the  middle,  the 
teeth  being  much  shorter  there  and  irregular.  In  this  it  resembles 
Eudoxochiton.  The  diagonal  rib  is  more  prominent,  and  the  eyes 
far  more  numerous  than  in  T.  rubridens.  The  nearest  ally  of 
schrammi  is  the  very  differently  sculptured  T.  crenulatn.*. 


3.  Specie*  of  Australia,  New  Zealand,  Philijui'me*,  etc.,  etc. 

T.  8UEZEN8I8  Reeve.     PI.  40,  figs.  16,  17. 

Shell  oblong  ovate,  valves  very  closely  concentrically  wrinkled 
at  the  sides,  with  oblique  wrinkles  toward  the  middle;  yellowish, 
delicately  stained  with  pale  scarlet  and  green  ;  ligament  horny. 
(Reeve.) 

f  of  Suez. 

C.  suezensis  K  i  i  \  i  ,  Touch.  Icon.,  t.  20,  f.  l.".-4  (May,  1847  ,— 
!>.-]  i.  Moll.  Mar  Ross.,  .  p.  235.—  COOK  i:,  Ann.  Ma-.  N.  H.  1386,  j». 
276.—  '  S  \vh.sx.  |  ),.>cr.  Aegypte,  t.  3,  f.  4.  —  Tonieia  f  suezensis 
(Vi:..  MS. 

Carpenter  writes:  Mucro  subposterior-median,  rectangularly 
elevated.  Interior:  anterior  valve  having  8,  central  1,  posterior 
valve  13  slits;  posterior  teeth  shorter,  bending  forward,  anterior 


[(  I  \. 

sharp.  i  ,     v«  -ry      deeply      pectinated.        I  ...  tdl         -inns 

minutely     denticulated.       This    species    :nnl     the     following,     with 
trniH'iitn.  are  intermediate  between    Tnnirin  and  .\r,it,ffi»/>/>'ii,-'i  ;  hut 
they  a-Tee  with  this    ireiius    in  the    porcellanoiis   texture,    deep  slits, 
angular  denticulated  -inus  and  pect  inated  teeth.      Tin-  .-li-ht  la: 
lion  of  the  girdle  appears  to  l>e  a  secondary  character. 

T.  NIGBOFUN4  r\i  \  (  'arpenter.      Unfigured. 

sholl  small,  rather  elongated,  elegantly  clouded  olivaceous  and 
l>ro\vn  ;  moderate]  v  arched,  the  dorsal  ridge  obtuse.  Lateral  areas 
moderately  defined,  ornamented  with  radiating  and  longitudinal 
wrinkles  irregularly  decussating,  with  black  dots  scattered  between 
them.  Central  areas  having  subparallel,  subdecussating,  scarcely 
regular  ribs,  obsolete  at  the  jugum.  Mucro  posterior,  elevated. 

Interior  having  8-10  slits  in  the  anterior,  1  in  the  central,  12-14 
in  the  posterior  valve  ;  teeth  in  the  posterior  valve  solid,  sloping, 
short  ;  sinus  broad,  denticulate.  Girdle  copiously  clothed  with  hair- 
like  scales.  Length  12,  breadth  6'2,  alt.  1-7  mill.  (Qpr.) 

Tahiti.  (Pease.) 

Acanthopleura  nigropunctata  CPU.,  P.  Z.  S.  1865,  p.  511.  —  PEASE, 
Amer.  Journ.  Conch,  vii,  p.  194.  —  Tonicia  nigropunctata  CPR.,  J/\ 

This  species  is  most  closely  allied  to  T.  suezensis,  but  the  latter 
has  the  valves  more  beaked  and  curved,  and  the  central  rugae  per- 
pendicular to  the  diagonal  lines,  while  in  this  they  are  nearly 
parallel  to  the  dorsal  ridge. 


T.  FORTILIRATA  Reeve.     PI.  40,  figs.  3,  4  (enlarged.) 

Shell  ovate  ;  valves  somewhat  beaked  in  the  middle  ;  posterior 
valve  umbonated,  blunt  ;  lateral  areas  rather  concave,  granulated 
anteriorly  ;  central  areas  strongly  arcuately  ridged.  Yellowish 
variegated  with  green,  stained  with  red  in  the  middle.  Ligament 
horny.  (Reeve.) 

Rait  if*  f-^'ind,  Torres  Sts.  (Ince)  ;  Port  Darwin,  8-10  fms.  sand 
and  mud  (  '(  !oppioger.) 

Chiton  fortilinihi*  KVK.,  Conch.  Icon.,  t.  18,  f.  112.—  C.  (ZWcm) 
fortiliratus  SMITH,  Zool,  '  Alert  '  p.  84. 

(  'arpenter  writes  of  the  type:  Anterior  valve  having  «>,  central 
valves  1,  posterior  valve  13  slits;  teeth  short,  numerous,  very  sharply 
pectinate:  short  at  the  hinder  end  but  gradually  becoming  a  little 
longer.  Kaves  short,  slightly  rugose,  not  spongy  ;  sinus  with  about 
20  teeth,  rather  broad,  flat.  Interior  whitish.  Outside  ashy 


2<»S  TONICIA. 

>usly  pencilled  and  marked  with  olivaceous;  beaks  small,  con- 
spicuous. Jugal  area  very  small,  smooth  in  front.  Central  areas 
with  :il»out  20  smooth  riblets,  curving  toward  the  middle  on  the 
median  part  of  the  areas,  and  toward  the  outside  of  the  areas  radiat- 
ing outward.  Lateral  areas  scarcely  raised,  having  faint  rows  of 
granules;  at  diagonal  rib  and  at  sutures  having  slight  elongated 
granules  toward  the  sutural  ribs  and  rows  of  metallic  dots  next  the 
diagonal  ribs.  Anterior  valves  with  granules  and  irregular  rows  of 
metallic  dots  alternating;  crenate  at  suture.  Posterior  valve  with 
median,  raised,  swollen  mucro ;  posterior  slope  straight.  Length  28, 
breadth  18  mill. 

The  single  specimen  collected  by  Coppinger  is  thus  described  by 
Smith  :  It  is  of  a  greyish-pink  color,  copiously  blotched  with  black 
along  the  sides  of  some  of  the  valves.  The  headplate  •*  -:•:- 
insertion  edge  is  much  thickened,  coarsely  striated  externally,  and 
is  divided  by  8  short  narrow  slits.  The  exterior  surface  is  coarsely 
subsquamately  granulated  throughout,  and  exhibits  numerous  black 
raised  dots,  disposed  in  rather  irregular  radiating  series.  The 
second  valve  is  long  in  comparison  with  those  which  follow,  feebly 
peaked  behind  ;  the  fourth,  fifth  and  sixth  plates  are  about  equal  in 
size  and  a  trifle  broader  than  the  third  and  seventh.  All  the  inter- 
mediate valves  are  very  coarsely  ridged  and  sulcated  on  the  central 
areas,  and  coarsely  grained  and  minutely  black-dotted  on  the  sides 
(lateral  areas).  The  ridges  are  flat-topped,  clean-cut,  nearly  smooth, 
attenuated  posteriorly,  wavy,  converge  on  each  side  toward  the  front, 
and  the  intervening  grooves  are  feebly  punctate.  All  have  the 
hinder  margin  nearly  straight  and  but  feebly  pointed  at  the  poste- 
rior apex.  *  •*  •*  The  posterior  valve  is  strong  and  thick,  obtusely 
mucronated  in  the  center,  very  coarsely  striated  and  serrated  upon 
the  thickened  insertion-margin,  which  is  subdivided  by  about  10  dis- 
tinct notches.  The  interior  of  the  valve  is  liirht  livid  bluish,  with  a 
reddish  stain  along  the  middle  of  all,  with  the  exception  of  the  last. 
The  mantle,  as  described  by  Reeve,  is  simply  "horny."  Length, 
without  girdle,  18,  diam.,  of  fifth  valve  9  mill.  Reeve's  type  is  a 
larger  >peeimen.  lieinir  -4  mill,  long,  13  wide,  without  girdle. 

I     -   \i:ri.vn:i:i  Aiiiras.      IM.  40,  ficr.  7. 

Shell  ovate,  elevately  convex.  carinat<  d.  :i>hy  white,  ornamented 
at  the  hinder  edges  of  the  valves  with  pale  spots,  the  spaces  between 
which  are  very  dark  olive,  melting  into  ei»nfu>rd  hands  of  a  paler 
hue  which  extend  nearly  across  the  valves;  valves  rostrate,  undul- 


K'MCIA. 

ately  concentrically  -iil>inil>ricately  sculptured  throughout:  the 
lateral  aiva-  not  raised  luit  separated  from  tin-  dorsal  areas  by  an 
elevated  ril>.  Posterior  valve  strongly  gibbous,  the  umbo  almost 
terminal;  mantle  margin  hrown.  Length  9  lines.  (Angas.) 

Port  Jackson,  Au-<trnli<i. 

nf.ri  AN<..,  I*.  X.  S.  1867,  p.  116,  223,  t.  13,  f.  30. 

Carpenter  gives  the  following  descriptive  notes : 

One  specimen  without  anterior  valve.  The  specimen  as  it  stands 
measures  length  17,  breadth  15  mill. ;  but  measuring  the  valves  only 
and  allowing  for  the  missing  anterior  valve  it  would  be  length  16, 
breadth  10  mill.  Shell  oval,  moderately  elevated,  the  dorsal  ridge 
acute;  olive  clouded  with  dark,  tessellated  with  light  so  as  to  appear 
toothed  at  the  sutures.  Mucro  central,  swelling,  elevated,  the  pos- 
terior slope  convex.  Jugal  area  a  rather  narrow,  nearly  smooth 
dorsal  line.  Central  areas  with  about  16  finely,  rugosely  sculptured, 
nearly  concentric,  but  faint,  grooves  on  the  otherwise  smooth  surface. 
Lateral  areas  slightly  raised  by  the  curved  diagonal ;  having  lines 
of  stumpy  granules  and  concentrically  rugosely  grooved  in  continua- 
tion of  the  sculpture  of  the  central  areas,  obsolete  at  sutures.  Pos- 
terior valve  concentrically  grooved  like  the  rest,  all  around.  Girdle 
nearly  smooth,  very  slightly  lanugate.  Posterior  valve  with  11 
slits ;  teeth  rather  sharp,  grooved  outside  ;  eaves  very  small.  Sinus 
broad,  flat,  deep,  having  about  17  very  slight  teeth. 

This  species  is  a  transition  toward  Acanthopleura  in  the  thrown- 
forward  teeth,  but  girdle  and  sinus  are  more  Tonicioid.  (Q>r.) 

T.  LAMELLOSA  Quoy  &  Gaimard.     PI.  40,  figs.  8,  9,  10,  11. 

Shell  small,  oval-elongate,  subelevated,  carinated ;  valves  trans- 
versely scaly-striated,  variegated  with  gray  or  ferruginous  ;  girdle 
thick,  smooth,  reddish  marked  with  radiating  brown  lines.  Anterior 
valve  having  10  crenulated  teeth,  posterior  9,  and  a  much  project- 
ing tuberosity.  Color  of  valves  grayish-yellow,  varied  with  brown, 
red  or  greenish.  Girdle  usually  yellow.  (Q.  &  (•?.) 

Length  15,  breadth  about  8,  alt.  5  lines. 

Tnnfja    Tabu. 

Chiton  lamellosw  Q.  &  G.,  Zool.  Astrol.  iii,  p.  386,  t.  74,  f.  29-32. 

This  species  has  the  mucro  more  posterior  than  any  of  the  preced- 
ing species. 
14 


TONK'IA. 

T.  CONFOSSA  Gould.    PI.  57,  figs.  33-36. 

Shell  oblong,  solid,  elevated,  the  side-slopes  straight,  dorsal  ridge 
<-;uinated.  Ashy  white,  delicately  maculated  with  various  shades  of 
reddi-h  and  purple-brown,  the  darker  color  irregularly  tessellating 
the  posterior  margin  of  each  valve. 

The  median  valves  are  moderately  beaked  ;  the  lateral  areas  a 
little  raised,  and  posteriorly  and  on  the  diagonal  are  very  peculia rly 
sculptured  with  transverse  narrow  le<l<je#y  like  the  edges  of  xhinab-* 
imbricating  from  the  outer  margin  of  the  valve  upward ;  median  por- 
tion of  the  lateral  areas  smooth,  dotted  in  a  widening  band  with  eyes. 
Central  areas  peculiarly  marked  with  sparsely  scattered  subtriangular 
in  some  places  arranged  in  irregular  transverse  rows.  Anterior 
valve  having  radiating  series  of  ^-shaped  imbricating  large  scales, 
alternating  with  narrow  bands  sparsely  dotted  with  eyes.  Posterior 
valve  hiring  the  prominent  mncro  near  the  posterior  end,  the  slope 
behind  it  vertical,  in  front  of  it  horizontal ;  a  narrow  band  of  eye 
dots  is  behind  each  diagonal,  and  they  are  very  sparsely  scattered 
over  the  rest  of  the  posterior  area. 

Interior  white.  Sutural  plates  separated  by  a  moderate  sinus, 
which  is  delicately  denticulate  except  in  the  second  valve.  Anterior 
valve  having  8,  median  1,  posterior  15  slits;  the  teeth  sharply  and 
deeply  pectinated  outside;  posterior  teeth  somewhat  directed  for- 
ward, deeply  pectinated,  the  slits  rather  shallow.  Eaves  narrow, 
slightly  projecting  downward  near  the  teeth,  and  very  narrowly 
grooved  just  outside  of  them. 

Girdle  blackish-brown,  rather  fleshy,  nude. 

Length  about  18,  breadth  11  mill.;  divergence  120°, 

Fiji  Is. 

Chiton  confossus  GOULD,  Proc.  Bost.  Soc.  Nat.  Hist,  ii,  p.  143 
(July,  1846)  ;  Expedition  Shells,  p.  5 ;  Wilkes'  Expl.  Exped.  Moll., 
p.  oL'7,  atlas  f.  434,  a,  b,  Otia  Conchologica,  p.  5. —  Chiton  (Lucia) 
confostus  GOULD,  Otia,  p.  242. — Lucia  confossa  GOULD,  Proc.  Bost. 
Soc.  viii,  p.  283. —  L»<-i/ina  confossa  DAI.I.. 

The  prominent,  posterior  mucro,  and  the  peculiar  sculpture 
render  this  species  easily  identified.  It  belongs  to  that  numerous 
East  Indian  group  (see  p.  206)  characterized  by  a  rather  swollen 
posterior  or  post-median  mucro,  forward-tending  posterior  teeth,  and 
by  the  generally  punctured  grooves  of  the  suriace-culptmv  ;  but  in 
this  species  the  character  of  the  sculpture  is  unique  in  the  total 
obsolescence  of  concentric  or  forwardly  converging  riblets  on  the 


[CIA,  :2  1  I 


mitral  aiva<,  and  tin-  development    of  angular  sejitten-d  pil 

The  tail-valve  is  emarginate  behind  a-  in   Kmlnj-or/iiinn  and  many 

Toniei:i<.      Kiur.  •'!•"•  represents  the  Interior  of  the  SeOOnd  valve,  which 
is  longer  than  the  following  valves,  as  usual  in   Tnn'n'ln. 

It  i-  imt  rasv  to  166  ln»\v  (Jonhl  could  write  so  confidently  of  the 
plurality  of  side  slits,  unless  he  examined  the  figures  in  the  Ivxploj- 
in.ir  Kxpedition  Atlas  instead  of  the  specimen  itself;  but  this  i 
doubt  the  case.  The  artist  oi'  the  expedition  in  d  rawing  these  figures, 
mistook  the  deep  pectination  for  veritable  slits,  and  represented  them 
as  such.  In  the  figured  specimen,  now  before  me,  the  girdle  in  dry- 
ing has  parted  from  the  eaves,  partially  exposing  the  deeply  pectin- 
ated insertion-plates,  as  represented  in  figures  434  b  of  the  Atlas  ; 
but  as  I  have  above  explained,  the  deeper  grooves  of  the  pectination 
have  been  very  erroneously  drawn  in  those  figures  as  slits.  The  fact 
is  that  although  the  grooves  are  strong  and  deep  on  the  outside  of 
the  plates,  they  scarcely  crenulate  the  summits  of  the  teeth,  and  are 
as  different  as  possible  from  true  slits. 

The  genus  or  subgenus  Lucia  (Lucilina)  has  therefore  no  stand- 
ing whatever,  but  becomes  a  synonym  of  Tonicia.  This  species  can- 
not be  included  in  Acantkopleura  on  account  of  the  different  arrange- 
ment of  the  eyes,  the  smooth  girdle  (which  in  this  species  seems  to 
be  more  fleshy  than  leathery),  and  the  denticulate  sinus. 

T.  PICTA  Reeve.    PL  40,  figs.  5,  6. 

Shell  ovate  ;  valves,  the  posterior  terminal  truncated,  ornamented 
with  short,  sharply  undulated  wrinkles,  the  interstices  between  which 
are  punctured  ;  anterior  edge,  of  the  lateral  areas  keeled  ;  pinkish- 
wliite,  showily  painted  with  green  and  scarlet  spots.  Ligament 
horny,  transparent.  (Rve.) 

Raine's  Island,  Torres  Sts.  (Capt.  Ince.) 

C.  pictus  REEVE,  Conch.  Icon.,  t.  15,  f.  79  (March,  1847.) 
Allied  to  C.  truucatus,  distinguished  by  its  sculpture  and  flattened 
growth.     (Rve.) 

T.  TRUNCATA  Sowerby.     PL  40,  figs.  1,  '2. 

Shell  oblong,  rather  elevated,  the  dorsal  ridge  rounded  ;  ashy- 
flesh  colored,  variegated  with  darker  or  olivaceous,  dotted  with 
black,  and  sometimes  rose-tinted  along  the  dorsal  i  i 

Valves  much  rounded  and  separated  at  the  ends  ;  entire  surface 
grauulose  ;  central  areas  engraved  with  superficial  waved  grooves  ; 


212  TONICIA-I  ANNKTTIA. 

lateral  areas  hardly  elevated,  irregularly  rugulose.      Mucro  behind 
the  middle,  much  elevated. 

Insidr  having  in  slits  in  the  anterior,  1  in  the  median,  14  in  the 
posterior  valve;  teeth  of  the  tail  valve  directed  forward  ;  those  of 
the  central  and  front  valves  sharper,  deeply  serrated  outside  and  at 
the  edge.  Sinus  moderate,  deep,  flat,  with  about  20  delicate  denti- 
cles. Length  38,  breadth  20  mill. 

Siquijor,  Philipp ines. 

Chiton  tnincatus  SOWB.,  P.  Z.  S.  1841,  p.  61.— REEVE,  Conch. 
Icon.,  1. 16,  f.  93. — Acanthopleiira  ?  truncata  GRAY,  P.  Z.  S.  1847,  p. 
68. —  Tonic'ci  truncata  ADS.,  Genera  i,  p.  474,  and  of  SHUTTLW.  and 
CPR. 

Resembles  Tonicia  (Fannettia)  disjuncta  in  the  partial  separation 
of  the  valves  at  the  sutures.  The  tail-valve  is  formed  much  like 
that  of  Acanthopleura. 

A  variety  with  nearly  smooth  valves  has  been  noted  from  Samar. 
Carpenter  described  in  MS.  a  Cumingian  specimen  as  T.  jugosulcata,. 
said  to  be  from  Tasmania,  but  he  later  regarded  it  as  a  form  of 
trinimta.  The  locality  Tasmania  is  very  doubtful. 

Section  Fannettia  Dall,  1878. 

Tonicia  §  *  *  ,  GRAY,  P.  Z.  S.  1847,   p.  G7.—Fannyia  GRAY 
Guide  Moll.  B.  M.,  p.  185  (1856).— Fannia  CPR.,  not  Fannia  Rob- 
ineau  Desvoidy,  1830. — Fannettia  DALL,  Proc.  U.   S.  Nat.  Mus. 
1882,  p.  284,  287,  289. 

This  section  is  like  Tonicia  in  all  respects  except  that  the  mucro 
is  flattened,  the  teeth  of  insertion  are,  somewhat  longer,  and  the 
broad  girdle  encroaches  upon  the  valves  at  the  sutures,  nearly 
separating  them. 

T.  DISJUNCTA  Frembly.     PI.  39,  figs.  35-41. 

Shell  oblong-ovate,  reddish-brown,  with  green  and  straw-colored 
markings;  valves  smooth,  glossy,  the  anterior  margins  of  the  dorsal 
valves  are  arcuate,  the  beak  only  of  the  next  forward  valve  cover- 
ing them,  </i\ -ini:  the  valves  a  disjointed  appearance.  Lateral  areas 
low;  mucro  of  tail  valve  median,  subplanate. 

Inside  white;  anterior  valve  having  9,  central  1,  posterior  valve 
9  short  slits ;  teeth  elongated  and  strongly  grooved  outside ; 
delicately  serrated  at  the  acute  margins;  teeth  of  tail  valve  short 
and  solid  behind,  el<>ni_r:itnl  in  front.  p]aves  narrow;  sinus  dentic- 
ulate. 


N  i  ii'  .1-1.1.1  i:  \. 


Girdle  smooth,  broad,  ^xteDding  lictwrni  tin-  valv<-s,  and  \vln-n 

living  marldrd  with  vivid  n-d,  ^ivm  and  blur. 
Length  62,  breadth  .",7  mill. 

Valparaiso,  f'lu'fi. 

Chiton  <{(.</  n  nrt  u.^  Kiir.Mr.i.Y,  /<><>].  .Journ.  iii,  p.  203,  suppl.  pi.  17, 
f.  5  (hrtwrrii  Oct.,  182<>  and  May,  1827).—  I:  <  onch.  Icon.  t. 

4,  f.  21.—  GOULD,  U.  S.  Kxpl.  'Kxped.,  Moll,  and  Sh.,  p.  329.— 
Fannyia  •'  dispuncta  "  [err.  typog.]  GRAY,  Guide,  p.  185.  —  Fannia 
iliyunrta  Cl'R.,  MS. 

"  The  transitions  between  this  species  and  the  normal  Tonicice  are 
so  gradual,  that  it  scarcely  seems  entitled  to  generic  rank.  The 
valves  are  not  much  more  covered  than  in  T.  truncata;  but  instead 
of  the  lateral  sinuses  being  angular,  they  are  gradually  rounded,  and 
extended  to  the  apices  of  the  valves.  The  principal  peculiarity  is 
in  the  flattening  of  the  mucro  ;  the  creature,  having  devoted  itself  to 
lateral  expansion,  had  no  need  to  push  its  tail  up  into  a  hump. 
The  slits  are  as  short  as  if  the  valves  were  fully  exposed,  only  extend- 
ing up  one-third  of  the  teeth  in  the  anterior  valve  and  one-half  in 
the  others.  Inside,  however,  the  gums  rise  to  the  level  of  the  slits, 
so  that,  when  seen  from  within,  the  shell  appears  perfectly  normal. 
According  to  Gould,  E.  E.  Moll,  p.  329,  the  girdle  is  "distinctly 
cleft  "  behind.  This  is  duly  represented  in  the  Atlas,  f.  417.  I 
have  not,  however,  been  able  to  trace  it  in  either  of  the  specimens 
examined.  That  in  Dr.  Gould's  own  cabinet,  although  in  good  con- 
dition, shows  no  trace  of  it.  Neither  Frembly  nor  Gray  allude  to  it. 


Genus  XV.    ACANTHOPLEURA  Guilding. 

Acanthopleura  GUILD.,  Zool.  Journ.  v,  p.  28  (in  part),  -f  Core- 
phium  GRAY,  Maugeria  GRAY,  Francisia  CPR. 

Valves  exposed,  beaked,  generally  lusterless  or  eroded  ;  provided 
with  eyes  on  the  forward  part  of  the  lateral  areas  and  the  end 
valves  ;  mucro  posterior  ;  interior  colored,  the  tegmentum  broadly 
inflexed  at  the  posterior  margin  of  each  valve.  Insertion  -plates  all 
conspicuously  pectinated  outside,  and  directed  forward.  Girdle 
thick,  covered  with  small  or  large  calcareous  spines. 

History  of  the  name  Acanthopleura.  —  Under  Acanthopleura, 
Guilding  defined  seven  sections,  naming  a  representative  of  each. 
His  scheme  is  here  reproduced,  the  modern  equivalents  of  the  species 
named  being  added  in  brackets: 


214  ACANTHOPLEURA. 

*  Zona   spinosa.       Chiton    yuwsua    Sow.,    Gen.    f.   1. 

\=Acantkopleura  spinosa  Brug.] 
*  *  Zona    spinulosa.       Ch.    tarmvokaefa    Gray,    Spicil. 

[==Plaxiphora.] 
*  *  *  Zona   granulosa.      Ch.   asellus    Lowe,   Zool.   Journ. 

[=Lep\doplewru*i  p.  13.] 
*  *  *  *  Zona  rugoso-granulosa.     Ch.  asselloides  Lowe.     [= 

Trachydermon  albus  L.,  p.  70.] 
*****  Zona  crinita.     Ch.  crinitus  Wood,  Index.      \=Acan- 

thochites.~] 
******  Zona  villosa.       Ch.  peruvianus  Frembly.     \=Ch«fn- 

jileura,  p.  28.] 

*******  Zona  farinosa.      Ch.  cinereus  Lowe.      \==Traehyder- 
mon,  p.  68.] 

As  neither  of  these  sections  were  selected  by  Guilding  as  the  typical 
group,  we  are  obliged  to  select  a  type  for  ourselves ;  and  of  course 
the  choice  must  be  limited  to  the  species  actually  enumerated  by  name 
in  Guild  ing's  *cheme  of  sections.  We  must  first  exclude  such  species 
as  are  already  provided  with  generic  names ;  and  glancing  down  the 
list  we  therefore,  eliminate  section  *  *  *,  which  falls  into  Risso's 
earlier  genus  Lepidopleurus,  and  section  *****,  which  belongs  to 
Acanthochites  Risso.  Of  the  five  sections  remaining,  *  *  was 
separated  by  Gray  in  1847  under  the  name  Plaxiphora.  Section 
******  was  denominated  Chcetopleura  by  Shuttleworth  in  1853  ; 
and  for  the  species  included  in  sections  *  *  *  *  and  *  *  *  *  *  *  *, 
Carpenter  established  the  genus  Trachydermon,  in  1863.  These 
successive  dismemberments  have  left  only  ihefirtft  tectitm  of  Guild- 
ing's  arrangement,  to  represent  the  original  genus ;  and  Chiton 
spinoms,  therefore,  becomes  the  type  of  Acanthopleura  Guilding. 

Unfortunately  for  science,  few  authors  have  arrived  at  this 
result;  but  the  fact  that  it  rests  upon  principles  "t  nomenclature 
from  which  there  is  no  appeal,  will,  it  is  believed,  be  evident  to  all. 

Since  Guilding's  publication  of  the  name,  it  has  been  considered 
by  the  following  systematists  : 

1840.  SWAINSON  defines  the  genus  (which  he  calls  "  Canth«}>]< 
<Miild."),   and   names    "(7.   spinom*,   Sow.   Gen.,    f.    1"    as    the 
representative  or  type.     No  other  species  is  mentioned. 

1847.  GRAY  defines  the  genus,  including  in  it  sections  as  follow.* : 

*  A.periiri'in'i  I, in.,   bicolor  Ad.,   hennnli  (Jray,   <"//-"/m  Sowb. 
[==Chatopkurci  -f- 


*  *  This  divide  into  three  siil>MTti«m~  : 

f  A.  nnbi/iit  (I ray.      [—EudoXOCMtOH.'] 

ft  A.pioia  Sow.,  *i>in  ii/ci-'i  S>\v.,  MMfiti  Gray,    j^xosa  Brug., 

/;/•/  S  I'jti'ifirn  (  I  ray.       [        ,!/'/"'/'/•/'/.] 

ftt  A.  f  git/"*  (imel.      [=Dwi0p  four] ;  A.  f  trum-titn.      [=2W- 
toio.] 

Neitlicr  of  these  sections  is  selected  by  Gray  as  typical ;  but  in  his 
"  List  of  the  Genera  of  Recent  Mollusca,  their  synonyma  and  types  " 
P.  Z.  8.  1847,  he  gives  on  p.  168,  no.  413,  "  Acanthopkura  (iuild. 
1835;  Gray,  1847.  Canthapleura  Swains.,  1840.  Ch.  8pin< 
It  appears  then  that  not  only  Swainson,  but  Gray  himself  selects  C. 
yi nn*u *  as  the  type  species. 

1853.  SHUTTI, i:\voiiTir,  in  a  most  scholarly  essay,  divided  Gray's 
Acautho/ilenra  of  1847  into  three  sections:  Chcetopleura  [equivalent 
to  Gray's  sect.  *  and  part  of  f  t  t>  and  including  C.  rugosu*  (Gray) 
Sowb.,  per  n  vi<nuis  Lm.,  gigas  Chem.]  ;  Eudoxochiton  [for  C.  nobilis 
Gray] ;  and  Acanthopleura,  restricted,  [equal  to  Gray's  Acantho- 
j>[>  ura  sect,  f  t  plus  Corephium,  with  some  other  miscellaneous 
species]. 

In  1856,  GRAY  again  made  a  cruel  onslaught  upon  the  genus; 
and  here  he  restricts  Acanthopleura  to  the  sect.  *  of  his  1847 
arrangement,  ignoring  the  fact  that  Shuttleworth  had  meantime 
given  a  new  name,  Chceto})leura,  to  that  section,  and  apparently 
forgetting  that  he  had  himself  said  in  a  former  paper  that  C.  spinosus 
was  the  type  of  Acanthopleura  !  In  the  same  paper,  he  proposes  a 
new  genus,  Minnjrriit,  for  the  following  species,  which  he  arranges  in 
two  sections:  f>  M-  nobilis  {_= Eudoxochiton  Shuttl.  1853].  ft* 
^[.  /n'rc'i  Sow.,  ,*/>! a iyera  Sow.,  oiven.ii,  a/nnosa  Sow.,  brevispinota 
Sow.,  magnified  Sow.,  C.  111.,  f.  52.  He  also  retains  his  genus  Core- 
phium for  C  echinatum  Sow.,  111.,  f.  47. 

1858.  Messrs  Adams,  in  their  Genera,  reunite  Acanthopleura  and 
Coreplu'inn,  with  a  choice  assortment  of  other  forms,  under  the 
genus  "  Chiton  /,in turns."  As  the  status  of  this  generic  name  has 
been  fully  discussed  by  me  on  p.  lf)0,  comment  here  would  be  super- 
fluous. 

1873-1882.  Carpenter,  in  his  MS.  arrangement  of  Chiton*  (an 
abstract  of  which  was  published  by  Dall,  Proc.  U.  S.  Nat.  Mus.  1881, 
p.  284,  287),  proposes  to  retain  the  name  Acantkoplevra  for  the 
group  of  Ch.  piceus;   Corephium  for    C.  echinatus ;  and   T7/'/ 
Cpr.,  ?ioi'.,  for   Ch.  spinosus.     This  arrangement  is  not  acceptable 


216  ACANTHOPLEURA. 

because  (1)  Ch.  piceus  is  not  mentioned  in  Guilding's  essay,  and 
therefore  cannot  be  the  type  of  his  genus.  We  are  not  concerned 
with  the  shadows  of  species  dimly  visible  upon  Guilding's  pages,  but 
with  the  species  actually  enumerated  by  him,  with  name  and  refer- 
ence. (2).  Franciaia  being  founded  upon  the  type  of  Guilding's 
Acanthopleura,  falls  as  a  synonym. 

The  eyes,  in  this  genus,  are  generally  obliterated  by  erosion 
except  at  the  edges  of  the  valves,  but  they  are  present  in  young 
Individuals,  as  in  Tonicia.  They  are  smaller  than  in  Tonicia,  and 
more  numerous.  In  Mesotomura  they  are  excessively  numerous, 
minute  and  oval.  In  Acanthof)leura  spiniger  they  are  larger,  cir- 
cular, and  scattered  around  the  bases  of  the  tubercles  on  the  lateral 
areas.  In  Maugeria  granulata  they  are  more  numerous  and  more 
scattered. 

The  interior  layer  of  the  valves  is  very  solid  and  dense,  as  in 
JSudoxochiton  and  Tonicia,  even  the  jugal  tract  inside  and  the  slit- 
rays  lacking  punctures.  The  tegmentum  is  deeply  grooved  over 
the  teeth  and  sutural-plates. 

Although  but  few  well- differentiated  species  of  A  canthopleura  are 
known,  the  range  of  individual  and  local  variation  is  great,  and  con- 
sequently an  extensive  literature  has  arisen,  and  the  synonymy  of 
the  species  is  exceptionally  involved.  It  is  not  improbable  that 
some  other  valid  species  exist,  but  if  so,  they  have  not  yet  been 
recognizably  defined. 

The  group  Lucia  Gld.  (Lucilina  Dall)  has  been  considered  a  sub- 
genus  of  Acanthopleura,  but  it  proves  to  be  a  synonym  of  Tonicia. 

The  genus  Acanthopleura  differs  from  Tonicia  mainly  in  the  duller 
and  sculptured  valves,  having  the  tegmentum  more  broadly  inflexed 
over  the  posterior  margins  ;  in  the  more  numerous,  smaller  eyes,  the 
fleshy  girdle  clothed  with  large  or  small  calcareous  spines,  etc.  It 
is  not  especially  allied  to  any  other  genus,  but  some  species  of 
Liolophura,  a  genus  near  Onithochiton,  are  externally  very  similar 
to  species  of  the  subgenus  M<intjc,-i<i.  They  may  be  distinguished  at 
once  by  the  smooth  toothless  ridge  in  place  of  the  insertion-plate  in 
the  tail  valve. 

All  of  the  species  can  be  readily  identified  by  the  following  key, 
whether  the  girdle-covering  be  preserved  or  not.  It  is  necessary  to 
remove  the  posterior  valve  of  a  specimen,  which  may  be  done  by 
soakin-  it  fur  .some  hours  in  warm  water.  The  arrangement  here 
given  is  believed  to  be  perfectly  natural. 


ACANTHOPLEURA.  -'  1  i 

n</  '•    nitlm),!,  urn. 

A.  tnMrtion-plate  of  tail-valve  long,  civiinlatrd  niit.-id«!,  and 
with  a  niiMliaii  slit  In-hind,  other  slits  suhobsolete  or  wanting  ; 
girdle  beset  with  spike-like  spines;  sinus  denticulate  ;  inte- 
rior purple-brown  in  the  cavity  and  transversely  engraved  ; 
the  sutural-plates  white,  (Mesotomnra),  A.  echinatwn. 

AA.  Insertion-plate  of  tail-valve  long,  crenulated  outside,  and  cut 
by  numerous  slits;  median  valves  much  wider  across  the 
sutural-plates  than  across  the  tegmentum  or  outer  coat  of  the 
valve ;  interior  not  engraved  (Acanthopleura  s.  s.} 

a.  Interior  purple  in  the  cavity,  sutural-plates  white ; 
median  valves  occasionally  Radsioid  ;  sinus  of  second 
valve  feebly  denticulate  ;  girdle  broad,  with  long  black 
spines;  exterior  black,  A.  spinosa. 

aa.  Interior  livid-flesh  or  livid  purple-colored ;  median 
valves  1-slit ;  sinus  smooth ;  girdle  wide,  with  numer- 
ous spinules;  exterior  dull,  generally  eroded, 

A.  spinigera. 

AAA.  Insertion-plate  of  tail-valve  short,  blunt;  median  valves  as 
wide  or  wider  measured  across  the  tegmentum  than  across 
the  sutural-plates  ;  sinus  smooth. 

a.  Insertion-plate  of  tail-valve  cut  into  teeth  by  7-11  well- 
developed,  subequal  slits  (Maugeria.) 

b.  Interior  sea-green  (intense  or  faded),  with  a 
black  tract  behind  the  sinus  ;  spines  of  girdle 
very  small,  valves  generally  eroded, 

A.  granulata. 

aa.  Insertion-plate  of  tail  valve  crenulated,  having  an 
oblique  slit  on  each  side,  the  ridge  between  them  either 
continuous  or  unevenly  serrated  (AmphitowivraJ 

b.  Median  portion  of  tail  insertion-plate  irregularly 
serrated,  but  without  true  slits  like  the  lateral 
tail  slits;  cavity  of  valves  purple-black,  sutural- 
plates  white  ;  valves  usually  not  eroded  outside, 
uniform  black,  granulated  at  the  sides ;  girdle- 
spines  rigid,  black,  tipped  with  butK 

A.  brevitpinotci. 


218  ACANTHOPLEURA. 


H>.  Interior  of  valves  blue-white,  with  a  black  tract 
behind  the  white-edged  sinus;  exterior  black 
with  a  light  stripe  on  each  side  of  the  dorsum, 
sides  granulated  ;  girdle  black,  A.  borb» 


Subgeuus  MESOTOMURA  Pilsbry,  1893. 

Me*otomura  PILS.,  in  the  Nautilus  vi,  p.  105  (Jan.,  1893). —  Core- 
]>hinm  GRAY,  P.  Z.  S.  1847,  p.  65,  68.— Not  Corephium  BROWN,  111. 
Conch.  G.  B.  edit.  I,  1827. 

Acanthopleura :  Valves  transversely  engraved  inside,  and  having 
the  sinus  denticulate ;  tail  valve  having  a  long,  continuous  insertion- 
plate,  slit  only  in  the  middle.  Girdle  beset  with  spike-like  spines. 

A  monotypic  subgenus  related  to  typical  Acanthopleura.  It  is 
remarkable  for  the  stout  spines  of  the  girdle,  the  long,  continuous 
insertion-plate  of  the  tail  valve,  and  the  finely  engraved  interior. 
In  the  last  character  it  can  only  be  compared  with  Enoplochiton 
/</'/'  r,  which  also  resembles  the  present  form  in  having  oval  eyes  in 
the  shell.  In  Afesotomura  these  eyes  are  excessively  numerous, 
exceeding  those  of  other  Acanthoids  in  number. 

A.  ECHINATUM  Barnes.    PI.  47,  figs.  6-17. 

Shell  oval  or  oblong,  solid,  rather  depressed  but  carinated  on  the 
dorsal  ridge,  the  lateral  slopes  slightly  convex.  Dark  brown  ;  where 
eroded  soiled  white. 

Valves  strongly  beaked,  having  a  narrow,  smooth  and  elevated 
dorsal  Ixnnl,  with  a  shallow  groove  on  each  side  of  it,  the  sides  of 
the  central  areas  doxelij  and  deeply  engraved  with  fine  flexuous 
grooves.  Lateral  areas  but  little  raised,  shining,  having  several  radial 
';/'  iin.-ifiilin  ntnmling  upon  a  smooth  ground,  which  is  closely 
.<tii,ldcd  n'lth  minute  eyes,  or  the  pits  left  by  their  destruction. 
Anterior  valve  having  radiating,  spaced  rows  of  pustules;  posterior 
valve  having  the  mucro  elevated  ami  near  the  posterior  margin. 

Interior  white,  unicolored  or  stained  with  reddish  in  the  depth  of 
each  valve ;  under  a  lens  it  is  seen  to  be  finely,  closely  engraved 
with  transverse  lines  and  elongated  punctures  on  the  forward  slope 
of  the  central  callus,  and  on  the  jugular  area  (fig.  12).  Slits  in 
anterior  valve  ft,  central  valves  1,  posterior  valve  1 ;  teeth  long, 
strongly  pectinated.  Sinus  finely  denticulate  in  all  valv<  -. 


v<   LHTBOPLB1  RA, 

(iinllr  liroad,   llr-hv,   l»«>.-t    with    strong  spike-like    ipL 

Lrill-  rxtrml  the  whole  length  (.ftlir  f'"<>t. 

ih  mo,  luvadth  .v>  mill.:  divergence  1 1.")°-1200. 
Length  68,  i.n-a.lth  40  mill. 

J'.ivt.i,  /V/-//  ,  Dr.  \V.  B.Jones);  <;<//<//"'.'/<>*  (P.  Ac.  Coll.) :  Val- 
parai.«>,  Chili  (  Fivmbly.) 

Chiton  whiiKitu*  BARNES,  Amer.  Journ.  Science  and  Arts,  (Silli- 
many)  vii,  p.  71,  t.  "»,  f.  4«,  4b.  (1823).— SOWERBY,  Conch,  rilu.-tr., 
f.  47  (young). —  GMton  tvberculiferui  SOWKKKY,  ('at.  Tankerv.,  p. 
29,  no.  688  (1825).—  Chiton  .</>/'// //r/-//x  FREMBLY,  Zool.  Journ.  iii, 
p.  196,  Suppl.,  pi.  16,  f.  1  (1827).—  Chiton  aculeatu*  REEVE,  Conch. 
Icon.,  t.  9,  f.  49.  Not  C.  aculeatn*  of  DESK,  et  al.,  nor  of  Linn. — 
Chiton  (Corephiwn)  spinifents  Frembl.,  STEARNS,  Proc.  U.  S.  Nat. 
Mus.  xiv,  1891,  p.  334. 

This  large,  spiney  species  is  not  likely  to  be  confused  with  any 
other,  being  very  distinct  in  external  features  as  well  as  in  the 
peculiar  insertion-plate  of  the  tail-valve,  the  engraving  of  the  inte- 
rior (reminding  one  of  Enoplocliiton  niyer  and  Chiton  granosus),  and 
the  denticulate  sinus.  The  girdle  spines  are  frequently  encrusted 
with  a  white  calcareous  deposit,  converting  them  into  globular 
pellets.  The  young  shell  also  lacks  slits  in  the  posterior  insertion- 
plate  (figs.  15-17,  x  2) ;  and  the  adults  sometimes  show  an  addi- 
tional shallow  notch  or  two  near  the  median  caudal  slit. 

Subgenus  ACANTHOPLEURA,  5.  sir. 

Acanthopleura  GUILDING,  I.  c.  (part),  and  PILSBRY,  The  Nauti- 
lus vi,  p.  105,  Jan.  2,  1893. — Frantisia  CARPENTER  in  DALL, 
Proc.  U.  S.  Nat.  Mus.  1881,  p.  284,  289,  290  (1882.) 

Acanthopleura:  Tail  valve  having  a  long,  many-slit  insertion- 
plate,  crenulated  outside  ;  median  valves  much  wider  across  the 
sutural-plates  (or  articulamentum)  thau  across  the  exposed  portion 
(tegmentum.) 

The  facts  which  cause  me  to  consider  this  the  typical  group  of 
Acanthopleura  have  been  discussed  above.  The  affinities  of  the  sub- 
genus  are  with  Mnuyerin  and  with  Mesotomnra.  With  the  latter  it 
agrees  in  the  coarsely  spiney  girdle,  interior  coloring,  denticulate 
sinus  and  long  insertion-plates;  but  it  differs  from  that  group  in 
having  a  many-slit  tail-plate,  in  the  frequent  (or  usual)  plurality  of 
side-slits,  the  nearly  smooth  exterior,  etc.  In  the  form  and  dentic- 


220  ACANTHOPLEURA. 

ulation  of  the  valves,  and  in  interior  coloring,  A.  spinosa  is  very 
closely  allied  to  A.  -•/>/»/;/<  r  Sowb.,  from  which  the  occasional  radsi- 
oid  slitting,  and  the  feeble  denticulation  of  the  sinus  in  the  second 
valve,  separate  it  specifically.  Dr.  Carpenter's  subgenus  Frandsia 
included  A.  spinosa  only. 

A.  SPINOSA  Bruguiere.     PI.  45,  figs.  80-87. 

Shell  oblong,  depressed,  smoothish  and  black  ;  girdle  wide,  covered 
with  long,  brittle  black  spines. 

The  valves  are  smooth  except  for  growth-lines  on  central  areas 
and  some  inconspicuous  radial  wrinkling  or  obscure  granulation  on 
the  vt'ry  feebly  defined,  small,  lateral  areas.  End  valves  somewhat 
rugose-granose  radially,  the  mucro  posterior. 

bmdepwrpl+redJnthe  middle,  white  on  the  sutural-plates  and 
the  region  of  the  lateral  slit-rays.  Sinus  of  second  valve  cut  into 
delicate  square  denticles  by  short  linear  slits,  but  in  the  other  valves 
the  denticulation  is  obsolete.  Slits  in  anterior  valve  15,  central 
valves  1  or  2,  posterior  valve  10  ;  teeth  of  end-valves  long,  grooved 
outside  and  crenulated  at  the  edges,  the  posterior  teeth  vertical ; 
teeth  of  intermediate  valves  triangular,  the  posterior  tooth,  when 
present,  very  small.  Sutural  plates  long,  separated  by  a  deep  sinus 
broader  than  the  plates. 

Girdle  wide,  rusty,  beset  with  long  brittle  black  spines  (fig.  86.) 

Length  50,  breadth  28  mill. 

Albany  Island,  £ape  York,  North  Australia  (Challenger.) 

Chiton  *pinn*u8  BRUGUIERE,  Journal  d'Histoire  Naturelle,  i,  p. 
25,  t.  2,  f.  1,  2  (1792).— LAMARCK,  An.  s.  Vert,  vi,  p.  321  (1819). 
— SOWI-:I:I;Y.  <  ieuera  of  Shells,  Cephala,  Chiton,  f.  1  ;  and  Conch. 
Illustr.  p.  1,  f.  151.— REEVE,  Conch.  Syst.  ii,  p.  12,  t.  134,  f.  151  ; 
and  Conch.  Icon.,  t.  9,  f.  51. — Framisia  spinosa  CARPENTER  MS. — 
Mn  <«j<rin  .<pino*u*  GRAY,  Guide  Moll,  B.  M.,  p.  184. — /'/•<// 
spino*a  HADDON,  Challenger  Rep.,  p.  30. 

The  radsioid  slitting  of  some  of  the  valves  and  the  lack  of  distinct 
areas  and  valve  sculpture,  well  distinguish  this  species.  The  >lits 
are  really  very  short,  but  are  continued  on  the  outside  as  grooves, 
up  to  the  eaves.  The  eyes  appear  as  minute  amber  colored  heads, 
sparsely  scattered  down  the  forward  half  of  the  lateral  areas,  but 
scarce ly  arranged  in  rows.  Poorly  preserved  or  very  old  specimens 
show  their  pits  only. 


\<    \M  n»ri.i.ri:  \.  •_>•_' 1 

Nutta/linn  .<C'ibr<i  live.  l»rar>  ;i  -li-lit  resemblance  to  thin  species, 
but  it  is  diMeivnt.ly  sculptured,  has  smooth  teetli  and  los  -piny 
girdle.  The  tail  plate  of  A.  spinosa  is  like  that  of  Kntli'ii-um  /»,//- 
icata,  on  account  of  the  long,  vertical  teeth. 

A.  SPINIGER  Sowerby.     PL  48. 

Shell  oblong-oval,  moderately  elevated  or  depressed,  lusterless, 
microscopically  granulated  an<l  having  a  more  or  less  developed 
sculpture  of  granules  which  either*  stand  distinct  or  coalesce  to  form 
concentric  wrinkles.  Color  dead-leaf  brown  or  soiled  whitish  where 
eroded;  generally  black  at  dorsal  ridge  and  sides  of  each  valve  or 
some  of  the  valves ;  on  each  side  of  the  black  dorsal  stripe  there  is 
generally  a  streak  of  green.  Girdle  broad,  black  or  alternated  with 
whitish.  The  valves  are  rounded  at  the  ends,  somewhat  beaked ; 
lateral  areas  but  little  raised,  granulated  or  wrinkled,  the  forward 
part  crowded  with  microscopic  bead-like  amber  eyes.  Central  areas 
having  wrinkles  of  growth  and  sometimes  low,  scattered  granules, 
more  numerous  and  stronger  at  the  sides.  Posterior  valve  having 
the  mucro  somewhat  behind  the  center. 

Interior  of  a  purple-brown  color,  darker  in  front  of  the  callus  of  the 
valve  and  on  the  sutural  plates,  lighter  behind  the  callus  of  the 
valve.  Sutural-plates  broad,  extending  laterally  much  beyond  the 
rounded  ends  of  the  tegmentum.  Sinus  rounded,  sometimes  black- 
edged.  Anterior  valve  having  9-11,  central  valves  1,  posterior 
valve  about  7  (6-10)  slits  ;  teeth  pectinated,  those  of  the  tail-valve 
much  longer  than  the  eaves. 

Girdle  broad,  closely  covered  with  calcareous  black  or  buff  spines 

Length  70,  breadth  43  mill. 

Fiji  Is. ;  Viti  Is.;  New  Caledonia  (A.  Garrett  in  Phil.  Acad.  Coll.)  ; 
Cagayait,  Isl.  of  Mindanao,  and  Siquijor,  Philippine  Is.  (Coming)  ; 
New  Guinea,  New  Ireland,  and  Tonga-Tabu,  (Quoy  and  Gaimard) ; 
Port  Essington  (Jukes)  ;  Port  Molle  and  Clairmont  and  Bird  Island 
(Coppinger);  Lat.  10°  36'  S.,  Long.  141°,  55'  K,  Albany  Island, 
Cape  York,  North  Australia,  in  6  fms.  (Challenger.) 

?  Chiton  aculeatus  LINNE,  Syst,  Nat.  x,  p.  667  (founded  upon 
Rumphius  Amboinische  Rariteitkamer,  pi.  10,  fig.  4.) 

Chiton  nicobaricus  aculeatu*,  CHKMN.  Conch.  Cab.  x,  p.  .">7">,  f. 
1692. —  Chiton  aculeatus  SPENGLER,  Naturhist.  Selskabet,  iv,  p.  78. 
—  Chiton  aculeatus  QUOY  &  GAIMARD,  Voy.  de  1' Astrolabe,  Zool. 
iii,  p.  373 ;  atlas,  t.  74,  f.  1-5  (1834). 


v  PHOPLEURA, 

3OWB.,  M  n.  Hist.  1*40,  p.  287,  Suppl.  ])1.  xvi, 

f.  2;   I'.  /.'>.  1841,  p.  61;  Conch.  Illustr.,  f.  68.—  REEVE,  Condi. 

.1.  14,  1'.  7-").  —  Mnii^f'-ri'i  ,*j,ini'j'ra  GRAY,  Guide  Moll.  B.  M., 
]).  184  (1857).  —  Ac.itnthojJi  ">-<i  .*/f!it!<i'-rii  Cri:.,  MS.  and  DAI.L,  ! 
U.  S.    Nat.   Mns.    1*S2,  ]>.    80.  —  Chiton   (Acanthopleura)    spiniger 
SMITH,  Zool.  Coll.  H.  M.  S.  '  Alert/  p.  81  (1884)  ;  P.  Z.  S.  189J  ,  p. 

-Awmthtif,/,  urn  *i>ini<j<-r  HADDON,  Challenger  Polyplac.,  p. 
I':).  —  Ac'tnfh'ijil''iira  balnnsce  ROCHEBR.  Bull.  Soc.  Philomath.  Paris, 
1881-2,  p.  1!»7. 

oil-nil!  (  JIIAY,  Guide  Moll.  B.  M.,  p.  184  (no  descrip- 
tion or  figure).  —  ??  Chiton  gemmatus  BLAINV.,  Diet.  Sc.  Xat.  xxxvi, 
p.  :.44. 


It  is  now  impossible  to  prove  that  this  is,  or  is  not,  the 

>/">•  of  Lin  IK'  ;    but   any   one  who   will   consult  the  original 

description,  "  C.  testa  octovalvi  striata,  corjtore  su  bactdeato"  then  turn 

to  Riimphius'  figure  cited   as  an  illustration,  will  be  prepared  to 

acquiesce  in    Hanley's   suggestion    (Ipsa   Linn.  Conch.)   that   the 

'•s  be  dropped  us  unidentifiable.     Gmelin  had  no  better  informa- 

tion upon  this  species  than  we;  and  therefore  his  additional  citations 

jures  are   valueless.     The  mere  fact  that  the  figure  cited   by 

Limn'  represents  an  oriental  species  is  offset  by  the  absolute  impos- 

sibility of  knowing  that  it  was  an  Acanthoineura. 

Besides  the  localities  given  above,  this  species  has  been  reported 
from  Sue/,  by  Is>el  (Mai.  Mar  Rosso  p.  235,  and  see  also  Cooke, 
Ann.  Ma-.  N.  II.  1885,  p.  276),  from  Aden  by  Haddon  (Challenger 
Polyplar.,  j>.  24).  It  has  been  figured  from  the  Red  Sea  by  Savigny 
(see  pi.  •">,  ii.ur>.  4,  1-2  of  his  folio).  Probably  Savii_rny's  \\^.  7,  1-3 
of  the  same  plate  represent  a  young  shell  of  the  same,  although  I 
havr  sri-n  none  closely  corresponding  in  sculpture.  The  eyc>  arc 
distinctly  drawn  by  the  artist,  a  rather  remarkable  circumstance 
when  we  remember  that  no  subsequent  illustrations  of  Chitons  show 
them  !  Additional  localities  are  Si  n-  /r«I<ni<l  reported  by  (£.  A  <  \. 
and  Jfnl.-mlii'li,  .Juj,,ni  by  Sclnvnck  (Amurl.  Moll.  p.  27.")':  but 
two  localities  must  lie  regarded  as  doubtful  until  confirmed  by 
i  fri'-h  specimen.-  or  a  critical  re-examination  of  the  specimens 
and  data  in  each  < 

The  study  of  the  Indo-Paeitic  Acanthopleiiras  may  be  somewhat 
>implilicd  l»y  the  elimination  of  i'l)  A.  f>or/>o,  ,!,;/,  characteri/ed  by  a 
•ail-valv-  and  (2;  the  "  Aninth- 


ACAM  HMI-I.I  i  i:\. 
;    Au-tralia    and    the   so-called    Acant  lioplmras    of  .Japan, 

which  arc  characterized  i>y  a  flat  ere-centie  callu-  in  pla<-»-  of  the 

teeth  in  ilic  tail-valve  (pi.  .~>3,  fiir.  -V 

Tin;  variation  ot'thi-  Speciei  is  irr«-at,  and  a  number  of  Hiibspeeilie 
or  varietal  forms  will  probably  be  distinguished  eventually.  My 
material  is  not  extensive  enough  to  permit  me  to  diagnose  these,  or 
to  indicate  their  areas  of  distribution  ;  and  I  therefore  offer  below 
the  original  descriptions  of  the  several  described  forms. 

Typical  >IMM»;I:I:  is  characterized  by  the  possession  of  longer 
spines  than  any  of  the  other  forms.  It  is  thus  described  by 
Sower  by  : 

C.  spiniger  Sowb.  (pi.  48,  fig.  22).  Shell  depressed,  ovate-elong- 
ated, all  over  granulated ;  valves  reclining,  ends  rounded ;  girdle 
wide,  furnished  with  numerous  subarcuate  spines.  .Length  2'1, 

width  1'5  inch.  Habitat ?  Mus.  Stainforth.  Another  spini- 

ferous  species,  rather  narrow  in  proportion  to  its  length ;  depressed 
and  finely  granulated ;  the  valves  are  rounded  at  the  lateral  extrem- 
ities, with  their  apices  leaning  backward,  and  their  lateral  areas 
scarcely  distinguished  ;  numerous  slightly  curved  spines,  nearly  one- 
half  an  inch  long,  cover  the  margin  ;  general  color  like  a  faded  leaf, 
with  dark  patches  of  reddish-brown  covering  the  lateral  and  part  of 
the  central  areas  of  some  of  the  valves,  and  a  dark  dorsal  band 
bordered  by  bright  green  and  white  (Sowb.  in  Mag.  Nat.  Hist.) 

The  fig.  22  is  a  copy  of  the  original  one  published  in  Mag.  Nat. 
Hist.,  and  fig.  23  of  that  in  the  Conchological  Illustrations,  which 
probably  represents  the  same  specimen.  Note  the  length  of  the 
girdle-spines. 

Reeve's  figure  (pi.  48,  fig.  27)  represents  a  larger  specimen, 
collected  by  Cuming  in  the  Philippines.  In  this  the  spines  are 
much  shorter.  Figs.  24-26,  pi.  48,  represent  valves  from  a  specimen 
very  similar  in  all  respects  to  Reeve's  figure  (see  pi.  48,  fig.  27). 
The  granulation  is  rather  obscure,  or  transformed  into  low  wrinkles. 
The  spines  on  the  very  wide  girdle  are  both  long  and  short  (1-1  \ 
mill.) 

Figs.  31,  32,  pi.  48,  are  drawn  from  a  specimen  from  the  Viti  I>. 
collected  by  Andrew  Garrett.  In  this  specimen  the  dorsal  ridge  has 
a  blackish-green  band  with  a  wider  fleshy-white  triangle  on  each 
side  of  it,  and  a  streak  of  green,  the  rest  of  the  surface  of  the  valves 
being  black  except  the  large  ashy-eroded  patch  on  each  side  of  the 
black  (eroded)  beaks.  The  central  areas  have  some  scattered  gran- 


224  ACANTHOPLEURA. 

ules  on  the  light  bands,  and  toward  the  diagonal  lines  ;  the  lateral 
areas  have  rather  coarse,  irregular  granules.  The  girdle  is  covered 
with  alternate  black  and  whitish  patches  of  spines,  theee  being  all 
curved  like  a  Dentalium,  rather  blunt,  the  longer  of  them  measuring 
about  2i  mill,  in  length. 

Another  specimen,  from  New  Caledonia,  is  similar,  but  has  no 
white  patches  on  the  girdle,  the  spines  being  3-3£  mill,  long,  and 
black,  often  tipped  with  light  color. 

The  C.  macgillivrayi  Ad.  (P.  Z.  S.  1855,  p.  120)  seems  to  be  very 
similar,  to  this  variety,  if  not  identical  ;  the  original  description 
follows : 

C.  macgillivrayi  A.  Ad.  Shell  oblong-oval,  a  little  elevated  ; 
black,  the  central  areas  painted  with  two  pale  longitudinal  stripes; 
valves  obtuse,  under  a  lens  seen  to  be  most  minutely  granulated, 
ornamented  with  concentric  undulating  rugose-grained  line ;  ter- 
minal valve  umbonated  in  front,  umbo  rather  smooth,  slightly  pro- 
duced; girdle  set  with  black,  curved,  slightly  obtuse  calcareous 
spines.  Feejee  Islands,  on  the  reefs  (  J.  Macgillivray).  This  is  a 
well-marked  and  handsome  species,  rather  more  than  two  inches  in 
length ;  the  surface  of  the  valves  is  finely  granulated  and  orna- 
mented besides  with  subgranulated,  wavy,  concentric  elevated  lines ; 
the  central  areas  have  a  pale  greenish  band  on  each  side  of  the 
umbo.  (Ad.) 

Carpenter  gives  the  following  notes  upon  the  types :  Four  spec- 
imens, with  A.  Adams'  autograph  label.  Bristles  rather  long  for 
the  group,  crowded  and  curved,  black,  but  often  tipped  with  light 
as  in  brevispinosa.  Sculpture  with  granules  like  borbonica  in  the 
young,  but  soon  changing  to  concentric  wrinkles.  Mucro  prominent, 
somewhat  antemedian,  the  posterior  slope  convex.  Jugal  area 
granose ;  in  one  specimen  only  are  there  white  streaks  making  V's  on 
the  valves.  Sculpture  of  central  areas  gradually  changing  from 
grains  into  wrinkles  toward  the  diagonals.  Lateral  areas  scarcely 
distinguished ;  concentric  wrinkles  predominating.  On  the  terminal 
valves  the  sculpture  is  much  finer,  the  rugulte  breaking  up  into 
grains.  Inside  color  dark.  The  divergence  is  very  variable,  one 
specimen  being  quite  elevated,  the  others  flatter;  measuring  103°, 
126°,  114°,  129°. 

The  >ir<i/t<itns  of  Reeve  seems  to  be  an  unusually  granose  example 
of  spiniger,  such  as  that  figured  on  pi.  48,  fig.  28.  The  description 
here  follows: 


ACANTIIMI-I.I  DBA, 

C.  grnnatn*    Kecve    (pi.  4<H,    figs.   29,    30).      Shell  ohlc.n. 
valves  strongly,    roughly   Drained,  especially   at.  the   sid«-s  ;  umbos 
smooth  ;  dirty  ash  or  stone  color,  grains  blackish,  nmbonal  eminence 
blotched    with    black;   ligament    horny,  jet    black.      Habitat  --  ? 
(Re< 

The  figured  type,  according  to  Carpenter,  has  lost  its  anterior 
valve  and  girdle  spines.  The  tail-valve  should  be  examined  in  order 
to  tell  whether  it  is  a  specimen  of  spiniger  or  of  borbonica,  but  I  am 
disposed  to  believe  it  the  former. 

Fig.  28,  of  pi.  48  is  drawn  from  a  large  specimen  belonging  prob- 
ably to  the  fjrdnatus  form.  The  dorsum  has  a  green  band  flanked 
by  creamy-flesh  colored  wider  bands,  more  or  less  suffused  with 
green.  The  surface  is  very  strongly  granulated. 

Reeve's  C.  CUNNINGHAMI,  to  which  piceus  Rv.  non  Gmel.  and 
obesm  Shutthv.  may  be  added,  probably  represents  a  variety  char- 
acterized by  the  large  size,  fine  girdle-spines,  etc. 

(7.  ciuminghami  Reeve  (pi.  49,  figs.  33,  34).  Shell  oblong-ovate, 
valves  rather  thick,  concentrically  ridged  throughout,  radiated  from 
the  umbones  with  raised  striae  ;  posterior  terminal  valve  retusely 
umbonated  ;  lateral  areas  scarcely  distinguished  ;  greenish-black, 
valves  longitudinally  painted  in  the  middle  with  a  brown  band  ; 
ligament  horny.  (Reeved) 

Australia. 


.,  Conch.  Icon.,  t.  27,  f.181,  Oct.  1847.—  "  C. 
magnificus  Gray?"  SOWB.  Conch.  Illustr.,  p.  2,  fig.  52  (not 
described.) 

The  identity  of  the  undescribed  C.  magnificus  (Gray)  Sowb.  non 
Desh.,  with  Reeve's  C.  cunninghami,  is  evident,  the  figures  being 
extremely  similar. 

Carpenter  gives  the  following  notes  on  the  type  :  "  One  specimen, 
marked  by  Baird  (and  rightly,  I  think)  to  be  the  same  as  piceus 
Rve.  The  valves  are  remarkably  well  grown,  in  quiet  waters,  and 
the  sculpture  is  rather  differently  developed  in  consequence.  The 
girdle  has  dried  in  around  the  valves,  and  the  hairs  are  worn  off 
except  in  the  sutures,  where  they  are  short,  crowded  and  black. 
Reeve's  figure  is  very  good  except  that  the  jugular  parts  appear  too 
decided;  they  are  simply  worn  smooth.  The  mucro  is  elevated, 
central,  posterior  slope  convex;  jugular  area  eroded  ;  central  areas 
wrinkle-granose,  rugulre  radiating  forward,  more  or  less  inter- 
15 


ACAXTHOPLEURA. 


rupted  into  (rrainile?  by  wrinkles  of  increment  ;  lateral  areas  scarcely 
defined.  Divergence  127°. 

The  following  is  believed  to  be  practically  identical  : 

C.  ptceus  Reeve.  (PI.  49,  figs.  38,  39).  Shell  ovate,  rather  thick, 
valves  concentrically  flatly  ridged,  interstices  between  the  ridges 
elevately  striated  and  sometimes  grained,  umbos  a  little  beaked  ; 
pitch-black,  greenish  on  each  side  the  umbonal  summit  ;  ligament 
horny,  profusely  beset  with  whitish  short  calcareous  bristle-like  pro- 
cesses. New  Holland,  on  the  rocks  (Cunningham).  This  I  believe 
to  be  the  true  C.  piceus  ;  it  is  a  thick  ponderous  shell,  of  which  the 
ligament,  when  in  a  good  state  of  preservation,  is  covered  with 
calcareous  bristle-like  processes,  as  in  C.  spiniger  but  much  finer. 
(Reeve.} 

Chiton  i>it-eas  REEVE,  Conch.  Icon.,  t.  13,  f.  70,  March,  1847.  — 
\8,  P.  Z.  S.  1867,  p.  223.—  TAPPARONE-CANEFRI,  Zool.  Viag. 
Magenta,  Malacologia,  p.  77  (1874).  —  C.  obesus  SHUTT.,  Bern. 
Mittheil.  1853,  pp.  67,"  79. 

Angas  says  that  this  species  is  freely  distributed  on  most  parts  of 
the  coast  of  New  South  Wales.  The  specimen  commented  upon  by 
Canefri  was  collected  at  Sydney  ;  but  both  may  be  founded  upon 
wrong  identifications.  Carpenter  writes  of  the  types  as  follows: 
"Four  specimens  from  Australia.  The  figure  of  Reeve  is  much 
larger  than  the  type,  and  would  stand  well  for  a  perfect 
The  largest  shell  measures:  length  77  J,  breadth  49 
mill.,  divergence  108°.  This  is  a  more  raised  shell  than  cuttning- 
hniiii,  probably  from  its  having  grown  in  rougher  water.  Spines 
very  short,  black,  sometimes  white.  Sculpture  almost  entirely  worn 
away  in  all  the  specimens  ;  when  seen  it  consists  chiefly  of  concentric 
wrinkle.-:  more  or  less  broken  into  granules.  The  lateral  areas  are 
scarcely  distinguishable;  mucro  very  perfect,  post-median  like 
'inyhumi,  but  rather  more  elevated,  as  is  the  rest  of  the  shell." 


Subgenus  MAUGERIA  Gray,  1857. 

.!/'/<"/'  rm  (i  KAY,  <  iuide  Syst.  Dist.  Moll.  IJrit.  Mas.,  p.  183  (in 
part).  —  Ac'iHthojileiira  CAKTI  \ri.i:,  Table  Reg.  Chit.  1873,  and 
Dal  I.  8,  Nat.  Miis.  1881,  p.  284,  289,  290  (in  part);  Not 

/  Guilding,  q.  v. 

Exterior  lusterless;  tail  valve  having  numerous  (7-12)  slit-  in 
the  short  crenulated  insi-rtiun-plate,  median  valves  1-slit,  the  exposed 
coating  or  tegnientum  widrr  than  the  articulanu-ntuni  or  inner  layer; 


227 


sinus   not    toothed,   the  sntural    plates    connected  across    it; 
thick,  densely  beset  witli  calcareous  spinelets.     Type  <  '/t.  'jranulatus 
(Jinel. 

ThU  •ubgenua  or  section  differs  from  Ac<inthnj>l>,i,-<i  and  Mcsoto- 
mnra  in  the  shorter,  blunt  tail  insertion-plate,  and  the  proportionate 
breadth  of  the  outer  and  inner  layers  of  the  median  valves.  It 
differs  from  Amph  Honiara  in  having  numerous  equally  developed 
slits  in  the  insertion-plate  of  the  tail  valve. 

VMTLATA  Gmel.     PL  50. 

Shell  oblong,  moderately  elevated  or  roundly  arched.  Surface 
almost  always  eroded,  dull,  ashy  or  cinereous,  generally  with  a 
patch  of  dead-leaf  brown  on  the  ridge  of  each  valve  ;  when  not 
eroded,  it  is  tawny-brown  or  black-brown,  with  a  pair  of  diverging 
whitish,  buff  or  pinkish  stripes. 

The  valves  are  beaked,  solid  and  thick,  with  somewhat  raised  but 
ill-defined  lateral  areas.  When  not  eroded,  the  lateral  areas  and 
pleura  are  closely  granulated  all  over,  and  the  end  valves  likewise; 
but  this  sculpture  is  generally  preserved  only  at  the  lateral  extrem- 
ities and  the  protected  anterior  margin  of  each  valve.  The  mucro 
is  swollen  and  posterior. 

Interior  sea-green,  often  varying  toward  lead-blue,  or  on  the 
sutural-plates  fading  to  nearly  white  ;  each  median  valve  having  a 
black  or  purple-  black  tract  between  the  sinus  and  the  summit  of  the 
callus,  this  tract  being  square  or  2-branched  at  the  ends.  Anterior 
valve  having  normally  8-10,  central  1  (rarely  2),  posterior  valve  9, 
(occasionally  7-14)  slits;  teeth  long  and  very  deeply  pectinated 
outside  ;  teeth  of  tail-valve  short  and  obtuse,  directed  forward,  very 
deejily  pectinated  outside  and  on  the  edge.  Sinus  slightly  concave,  or 
convex  and  notched  at  the  sides,  not  denticulate. 

Girdle  thick  and  fleshy,  densely  covered  with  short,  unequal  spine- 
lets  (pi.  50,  figs.  40,  41,  x  13)  which  are  short,  calcareous,  and  either 
black  or  white  ;  the  black  spines  (fig.  41)  being  frequently  longer 
than  the  white,  and  straight  or  nearly  so;  the  white  spines  (fig.  40) 
are  short,  very  unequal  and  shaped  like  the  shell  of  Oididus. 

Bermuda;  Bahamas;   Ch<irl»tt>    Jlnrbor,    Vaccas   Key,    etc., 
Flnriil'i  :  <////'/v  I  !''.>•/  Indie^  southward  to  Trinidad  and  the  Spanith 
M<i  in. 

Chi  f  on  in<i</ell(t.r,iciis  GMKLIX,  Syst.  Nat.  xiii,  no.  12,  p.  3204. 
(—  Chemn.  viii,  p.  279,  pi.  95,  f.  797,  798,  Chit»n  mittj'-/laniciis).-~ 


228  ACANl  IlnPI.KURA. 

WOOD,  General  Conchol.,  p.  18,  t.  3,  f.  6  (1815).—  Chiton  granulatu* 
GMEL.,  /.  c.  no.  16,  p.  3205  (=Die  j»«-h.-«-/<ir<irze  granulirte  Chiton 
CHEMNITZ,  Conchyl.  Cab.  viii,  p.  284,  t.  96,  f.  806).— WOOD,  Gen. 
Conch.,  p.  9. — d'ORB.,  Moll.  Cuba  (Ramon  de  la  Sagra,  Hist),  ii,  p. 
200  (1853). —  Chiton  i>iceus  GMEL.,  I  c.  no.  17,  p.  3205  (Chemn.  viii, 
p.  285,  t.  96,  f.  807-810).— WOOD,  Gen.  Conch.,  p.  8,  t.  1,  f.  3.— 
SOWERBY,  Conch.  Illustr.  f.  147.— SHUTTLW.,  Bern.  Mittheil.  1853, 
p.  78,  and  of  most  later  writers  on  the  Antillean  fauna. —  Chiton 
occidental™  REEVE,  Conch.  Icon.,  t.  14,  f.  77a.  (1847). —  Chiton  sala- 
'!rr  SPENGLER,  Skrivter  af  Naturhist.  Selskabet,  iv,  p.  80  (= 
Chemn.  viii,  f.  806. —  Chiton  tuberculatus  L.,  SCHROETER,  Einleit. 
iii,  p.  494,  t.  9,  f.  19  ("Der  cylindrische  Chiton  ")  ;  not  C.tubwula- 
t\i8  Linne. —  Chiton  nnguiculatus  BLAINVILLE,  Diet.  Sc.  Nat.  xxxvi, 
p.  544. —  (7.  conrexus  BLAINV.  /.  c. —  Chiton  (Acanthopleurd)  blaum-ri 
SHUTTL.  Journ.  de  Conchyl.  1856,  p.  170. — ?  C.  (A.~)  mucronulatus 
SHUTTL.,  Bern.  Mittheil.  1853,  p.  79. 

This  species  is  the  common  Chiton  of  the  West  Indies,  being 
abundantly  distributed  throughout  the  group,  the  specimens  before 
me  being  from  the  following  localities :  Bermuda  (Heilprin)  ;  Key 
Vaccas,  Florida  (Calkins,  Hemphill)  ;  Bahamas  (H.  C.  Chapman, 
J.  J.  Brown,  F.  Stearns)  ;  Jamaica  (Johnson  and  Fox)  ;  San  Dom- 
ingo (Gabb);  St.  Thomas  (Swift);  Dominica  (Sharp)  Monos, 
(Sharp) ;  Atlantic  coast  of  Costa  Rica  (Gabb).  The  specimens 
are  almost  always  eroded,  the  original  color  and  sculpture  being 
quite  lost.  Although  the  species  is  very  variable,  no  local  forms 
deserving  varietal  rank  are  known  to  me. 

Figures  39-41  represent  a  St.  Thomas  specimen,  eroded  in  the 
usual  manner.  Fig.  48  is  also  drawn  from  a  St.  Thomas  specimen 
in  which  the  sculpture  is  perfectly  preserved,  and  the  color  uncom- 
monly dark. 

Figures  44-47  represent  valves  of  examples  from  St.  Domingo. 
The  non-eroded  forward  part  shows  a  central  brown  band,  with  a 
flesh-colored  band  on  each  side  of  it.  This  coloring  is  also  found  in 
most  specimens  from  Florida  Keys  (fig.  43),  Jamaica,  St.  Thomas. 
Specimens  from  the  Bahamas  have  the  two  light  stripes  blue-white, 
and  are  strongly  corrugated. 

Tho  tail-valve  varies  greatly  in  respect  to  the  prominence  of  the 
mucro.  In  some  specimens  (fig.  46)  it  projects  beyond  the  pos- 
terior edge  of  the  valve ;  in  others  it  hardly  attains  the  edge;  but 
these  variations  do  not  seem  to  be  correllated  with  other  characters. 


Li   \M -IIMI-I  i  ri:\.  229 

The  identity  of  C.  ma<j>ll<itii<'ii*  ( \ in.  and  Chcmn.  with  tlie  West 
Indian  species,  although  extivmelv  probable,  cannot  be  regarded  as 
absolutely  established.  At  all  events  the  name  is  hardly  acceptable, 
for  no  Antntfio/ilcnm  of  this  type  has  been  collected  at  or  near  the 
Strait  of  Magellan.  Rochebrune's  citation  (Moll.  Cap  Horn)  is 
worthless,  on  account  of  his  ignorance  of  generic  and  specific  charac- 
ters in  this  group,  and  his  false  synonymy  in  the  case  of  this  species. 
Gmelin's  C.  (jrnnulitns,  the  next  name  in  order  of  priority,  was 
founded  upon  specimens  from  St.  Thomas  excellently  described  and 
figured  by  Chemnitz.  The  identity  of  the  next  form  described 
by  Gmelin,  jritttf*,  is  also  moderately  sure.  Reeve's  C.  occidentalis 
{see  pi.  50,  fig.  42)  is  an  ordinary  form  of  granulatus. 

Shuttleworth  has  described  two  West  Indian  Acanthopleuras  of 
which  I  have  not  seen  authentic  examples.  His  descriptions  here 
follow : 

C.  (Acantfiopleura)  inner oiwlatus.  Shell  oblong-ovate,  elevated, 
narrowed  in  front,  black-brown,  unicolored  ;  valves  all  over  very 
minutely  concentrically  punctate-striate,  carinated  dorsally,  pro- 
duced backward  in  a  short  apex  ;  lateral  areas  slightly  elevated. 
Girdle  spotted  with  white,  having  scattered  very  minute,  sand-like 
grains.  Length  9,  breadth  6  mill.  Porto  Rico,  Blauner !  Described 
from  a  single  specimen  ;  distinguished  from  the  young  of  granulata 
by  the  form  and  especially  the  very  minutely  sanded  girdle.  Shell 
inside  dull  whitish,  slightly  greenish. 

This  may  prove  to  belong  to  some  other  group.  C.  (Acantho- 
pleura)  blauneri  Shuttl.  was  founded  on  a  single  black-brown  spec- 
imen from  Porto  Rico,  having  unicolored  black  girdle  densely 
-clothed  with  very  minute  spines,  more  minute  than  in  piceus,  from 
which  blauneri  also  differs  in  being  more  depressed  and  more 
minutely  sculptured.  Length  52,  breadth  32  mill.  I  do  not  see 
that  this  falls  outside  of  the  well  understood  range  of  variation  of 
A.  granulata. 

The  following  unfigured  form  may  prove  to  be  a  distinct  species  if 
the  locality  be  confirmed. 

Chiton  (Acanthopleura)  piceolus  Shuttl.  Shell  ovate,  wider 
behind ;  obscure  olivaceous,  maculated  with  black  at  the  middle  of 
the  back  and  at  the  sides;  valves  all  densely  and  minutely  pus- 
tulose-granulate ;  areas  entirely  obsolete.  Girdle  minutely  and  very 
densely  sandy-spinulose,  alternately  maculeated  brown  and  white. 
Length  10,  breadth  6  mill.  (Shuttl.  Bern.  Mittheil.  1853,  p.  82.) 

Tenerife,  Canaries,  (Blauner)  ;  rather  common. 


230  ACANTHOPLEURA. 

Intense  black-green  inside.  Color,  pattern  and  sculpture  are  as 
in  young  C.  piceus  Gmel.,  but  it  differs  in  the  much  smaller,  more 
delicate  girdle  spicules.  (Shuttl.) 

Subgenus  AMPHITOMURA  Pilsbry,  1893. 

Amphitomura  PILS.,  The  Nautilus,  Jan.,  1893,  p.  105.  Type  Ch. 
borbonicu*  Dh. 

Girdle  and  all  valves  but  the  eighth  formed  as  in  Maugeria.  Tail 
valve  having  the  insertion-plate  very  short,  with  blunt,  crenulated 
edge,  and  a  single  shallow  oblique  slit  on  each  side,  and  sometimes 
some  uneven  serrations  in  the  middle. 

The  Mopaloid  slits  of  the  tail-valve  are  very  peculiar,  but  the 
structure  is  fore-shadowed  in  some  forms  of  Maugeria. 

A.  BORBONICA  Deshayes.    PI.  45,  figs.  76,  77,  78,  79. 

Shell  oblong,  rather  elevated,  solid,  roundly  arched,  dull  bln-k 
with  a  white  stripe  on  each  side  of  the  median  black  band;  rusty 
blackish  and  gray  when  eroded  ;  girdle  black. 

The  lateral  areas  are  but  slightly  raised,  and  are  densely,  fitn-ly 
hired  with  close  radiating  rows  of  granules;  the  sides  of  the 
central  areas  are  also  granulated  adjacent  to  the  lateral  areas,  but 
toward  the  middle  this  sculpture  disappears,  leaving  only  a  faint 
microscopic  granulation.  End  valves  radially,  densely,  granulated, 
the  mucro  posterior,  rather  elevated. 

Interior  blue-white,  each  median  valve  having  a  broad  black  square- 
ended  crescent  in  front  of  the  callus,  the  inflexed  posterior  margin 
ashy-olive,  lateral  triangles  lead-white.  Sinus  deep,  rounded. 
Anterior  valve  having  10,  central  valves  1,  posterior  valve  2  slits 
(figs.  76,  77)  ;  teeth  pectinated,  those  in  the  front  of  the  head-valve 
short.  Eaves  wide,  black,  channelled  along  the  teeth.  Muscle 
impressions  on  sutural  plates  and  end  valves  deep. 

Girdle  fleshy,  black,  covered  with  black  spinules  about  li  millim. 
long. 

Length  50,  breadth  30  mill. ;  divergence  about  125°. 

Mauritius ;  Reim  Mm. 

Chiton  borbonicus  DH.,  Moll.  Reunion,  p.  37,  t.  v,  f.  12,  13.— C. 
(Acanthojilfnra)  horbonicus  Dh.,  MARTENS  in  Mobius'  Reise  nacli 
Mauritius,  p.  300. — ?  ?  ('hit.,,,  ntbvbmu  WOOD,  Index  Test.  Suppl., 
t.  1,  f.  4. 


ACANTiii  >ri  I  ri:  \ 


Keadilv  rec..  Lrni/ed  l>y  the  Mack,   irranulated   ridtt,  an.  I  HBOOthet 

;riped  rid.ire,   in  connection  with  the  peculiar  insertion-plate  of 

tin-  tail  valves.       Smith    has    placed    the  species   with   douht    in    the 

synonymy  of  A»  »i»iiii[icr,  where   it  certainly   does  not  belong  ;  and 

Martens,  also  erroneously,  suggests  its  identity   with    ('It.  i>ctli<>l<itn.< 

Sow. 

The  insertion-plate  of  the  tail-valve,  while  in  some  specimens 
somewhat  uneven,  is  not  often  so  serrated  as  in  A.  br'-rinftinosa.  It 
further  differs  from  that  species  in  the  striped  back  and  the  interior 
coloration.  The  crescent-shaped  black  patch  behind  the  sinus  inside 
is  square  or  forked  at  the  ends,  as  in  A.  granulata,  and  the  edge  of 
the  sinus  is  white. 

A.  BRI:\  isriNosA  Sowerby.     PI.  47,  figs.  18,  19,  20,  21. 

Shell  oblong  oval,  depressed,  each  valve  beaked  and  concentrically 
rugose-granuliited.  Color  black,  the  girdle  narrow,  clothed  with 


The  valves  concentrically  wrinkle-grained  at  the  sides  of  the 
central  areas,  and  the  ill-defined  lateral  areas  are  cut  into  granules 
by  concentric  and  radiating  grooves.  End  valves  finely  grooved  radi- 
ally t  finely  wrinkled  concentrically  ;  mucro  posterior,  prominent  and 
rather  acute. 

Interior  blackish-brown  or  /nirple-browti  except  the  sutural-  and 
insertion-plates  which  are  white.  Sinus  broad,  deep,  rounded. 
Anterior  valve  having  7-8,  central  1,  posterior  2  slits  and  a  number 
of  irregular  serrations  ;  anterior  teeth  moderately  long,  finely  pect- 
inated outside  ;  posterior  teeth  very  short,  blunt,  obsoletely  pectinated. 

Girdle  rather  narrow,  clothed  with  rigid  black  spinelets  tipped 
with  buff. 

Length  42,  breadth  26  mill.  ;  divergence  about  130°. 

Johanna,  Comoro  Is.  (Cuming,  Cpr.)  ;  Zanzibar  (Cpr.)  ;  Cape  of 
Good  Hope  <m<!  Mnd<tga*cnr  (Paris  Mus.)  ;  Strait  ufSnint  Vincent, 
Cape  Verde  I*.  (Cessac.) 


Chitnn  I,,-,  -i-i-tplnoxua  SOWB.,  Mag.  of  Nat.  Hist.  1840,  p.  287.  t. 
xvi,  f.  1;  Conchol.  Illustr.,  f.  136.  —  KI:I:\I:,  Conch.  Icon.,  f.  52.  — 
Acniitln>pl'-imi  brcvi-xpinoaa  ROCHEBR.,  Nouv.  Arch,  du  Mus.  J881, 
p.  240. 

Part  of  the  localities  given  above  are  probably  incorrect,  A  good 
many  shells  procured  at  "  Cape  of  Good  Hope"  and  "Zanzibar" 


232 

never  grew  at  those  places.      The  evidence  in  favor  of  the  Comoro 
Is.  is  more  satisfactory. 

This  species  is  closely  allied  to  A.  borbonica  in  sculpture,  but  it 
differs  in  having  flatter,  thinner  valves,  longer,  white-tipped  spines, 
in  lacking  the  white  dorsal  stripes  as  well  as  in  the  color  of  the  inte- 
rior. Finally,  the  characters  of  the  tail  insertion  plate  differ. 

Subfamily  LIOLOPHURIN^E. 

Median  and  anterior  valves  provided  with  eyes,  and  having  well- 
developed  insertion-plates  with  slits,  the  teeth  pectinated  outside,  not 
thickened  at  the  edges  of  the  slits.  Posterior  valve  with  the  mucro 
posterior  and  terminal ;  its  insertion-plate  obsolete,  reduced  to  a  low 
ridge  or  flat  ledge  of  callus,  which  is  unslit  (except  in  Schizochiion ) 
and  continuous  posteriorly  or  interrupted  in  the  middle  by  a  caudal 
sinus.  Gills  as  long  as  the  foot. 

This  group  is  closely  allied  to  Chitonidce  and  has  doubtless  been 
derived  from  the  Tonicioid  branch  of  that  stock.  It  is  separated 
from  them  on  account  of  the  degeneration  of  the  posterior  valve  and 
esj>ecially  its  insertion-plate, — a  character  of  vastly  less  importance 
than  Carpenter  supposed.  The  median  notching  of  the  tail  valve 
behind  is  also  extremely  variable,  as  is  exemplified  by  such  closely 
allied  forms  as  Lorica  volvox  and  L.  angasi.  All  of  the  genera  of 
>nidcet  Chiton,  Eudoxochiton,  Tonicia  and  Acanthopleitra,  show 
species  in  which  the  tail  valve  has  an  incipient  caudal  sinus,  or  in 
which  the  insertion-plate  is  becoming  obsolete,  or  both  conditions.  It 
is  only  necessary  to  mention  Chiton  jugosus  (p.  178),  Eudoxochiton 
(pp.  193,  194),  Tonicia  confossa  (p.  210);  Acanthopleura  sjrinigera, 
all  showing  more  or  less  posterior  emargination  ;  Acanthopleura 
grnnii/nfu  and  the  section  Amphitomura  have  the  posterior  insertion- 
plate  very  short,  some  forms  of  the  latter  having  it  nearly  deprived 
of  slits.  Compare  with  these  Schizochitou  and  Lorica,  the  latter 
having  the  insertion-plate  short  but  distinctly  creuulated.  It  is 
probable  that  deposits  not  older  than  Miocene  will  furnish  the 
generic  links  now  missing  between  the  series  of  forms  here  included 
tnd  those  grouped  in  L i»lo/> h ///•///</. 

It  is  a  notable  fa<-t  that  the  generic  groups  of  Toniriitur  and 

'  MMMII  to  mutually  correspond  to  one  another,  as  though 
the  several  generic  stocks  of  the  former  subfamily  had  been  simul- 
taneously modified  in  the  same  manner,  thus: 


IJolophnrin;.-. 
H    disposed    in    radiat.ing    hands;! 

valves   polished  and    bright  colored 

n  ...        .  ,,    >    Ontthochiton. 

outside,  ponvllanous  \vitlnn;  girdle 

[leathery,  nude. 

f  Eyes  scattered  among  the  tubercles! 

of  the  surface,  which  is  rough  and 

Maugtna     <  .  .  '     .  '   .   ..    }•  Liolophura. 

lusterless ;     interior     dark ;     girdle 

[clothed  with  calcareous  spines. 

(Eyes  very  minute,  oval,  scattered;! 
surface  of  valves  brown  and  polished  I     —       7    ,  . 
,.         >   Enoplochiton. 
outside  when  not  eroded,  peculiarly 
sculptured  inside. 

The  genera  Lorica  and  Schizochiton  have  no  representatives  in  the 
Toniciitice,  for  while  they  are  closely  allied  to  the  latter,  they  have 
been  differentiated  along  a  line  away  from  that  taken  by  Onitho- 
chiton  and  its  immediate  allies. 

Synopsis  of  Genera. 

A.  Median  valves  having  eyes  developed  only  on  the  diagonal  ribs. 
Sinn*  notably  narrow  and  small.     Insertion-plate  of  tail  valve  a  low, 
rounded,  rugose  ridge  more  or  less  notched  or  waved  upward  in  the 
middle  behind,  or  sharp,  long  and  pectinated. 

B.  Eyes  large,  situated  on  the  diagonal  ribs  and  on  the  ribs  of  the 
head  valve,  the  latter  corresponding  to  slits   in  the  insertion-plate. 
Girdle  having  minute  calcareous  spines. 

Genus  XVI.     SCHIZOCHITON  Gray. 

Much  elongated.  Posterior  valve  having  a  deep  caudal  sinus 
with  one  or  two  notches  on  each  side  of  it  in  the  insertion-plate. 
Head  valve  with  few  (about  6)  slits.  Girdle  sparsely,  finely  spinulose, 
slit  behind. 

BB.  Eyes  reduced  to  minute,  fuuctionless  punctures  on  the  summit 
of  the  diagonal  ribs,  and  entirely  absent  on  the  head  valve,  the  riblets 
of  the  latter  not  corresponding  to  internal  slits.  Qifdfa  dfnseli/  s<'ah/. 

Genus  XVII.    LORICA  H.  &  A.  Adams. 

Oval  or  ovate,  elevated.  Posterior  valve  having  a  deep  caudal  sinus 
or  a  shallow  wave,  the  insertion-ridge  otherwise  uninterrupted. 


234  SCHI/OCHIToN. 

Head  valve  with  numerous  (8-10)  slits.  Girdle  den-ely  clothed 
with  minute,  convex,  crowded  scales. 

Section  LORICA  s.  str.  Caudal  fissure  deep ;  sinus  v-shaped ; 
girdle  widest  at  the  sides,  slit  behind.  ^ 

Section  LORICELLA  Pils.  Caudal  fissure  reduced  to  a  shallow 
wave;  sinus  bilobed  ;  girdle  widest  in  front,  not  slit  behind. 

AA.  Eyes  developed  upon  the  lateral  areas.     Sinus  wide  and  large, 
'ion-plate  of  the  tail  valve  reduced  to  a  smooth  ledge  or  rid<jey 
ha  ring  no  posterior  sinus  or  wave. 

Genus  XVIII.     ENOPLOCHITON  Gray. 

Valves  polished  or  deeply  eroded,  dark  brown  outside  and  within, 
having  excessively  minute  eyes  scattered  over  lateral  areas  and 
head  valve  (when  not  eroded) ;  interior  very  densely  and  minutely 
and  peculiarly  grooved  and  punctured.  Girdle  fleshy,  bearing 
separated  rude  scales. 

Genus  XIX.    ONITHOCHITON  Gray. 

Valves  polished,  colored  outside,  porcellanous  and  smooth  within, 
having  the  eyes  disposed  in  radial  bands  on  each  lateral  area  and 
the  head  valve.  Girdle  leathery,  microscopically  velvety. 

Genus  XX.    LIOLOPHURA  Pilsbry. 

Valves  lusterless,  granulated,  having  the  minute  eyes  scattered 
over  the  lateral  areas,  sides  of  the  central  areas  and  head  valve. 
Girdle  densely  covered  with  stout  calcareous  spines. 


Genus  XVI.    SCHIZOCHITON  Gray,  1847. 

Schizochiton  GRAY,  P.  Z.  S.  1847,  pp.  65,  68,  169. 

Valves  exposed,  elongated,  beaked,  bearing  a  single  row  of  eyes 
upon  each  diagonal  rib  of  intermediate  valves  and  each  radiating 
rib  of  the  head  valve,  the  ribs  of  the  latter  corresponding  in  position 
to  slits  in  the  pectinated  insertion-plate.  Sinus  narrow.  Posterior 
valve  having  a  deep  posterior  fissure,  and  several  slits  on  each  side 
of  it.  (Jirdle  slit  behind,  bearing  small  calcareous  spinelets.  Type 
Ch.  incitu*  Sowb. 

This  genus  might  as  readily  be  referred  to  Ttmiri!/ur  as  to  Liolo- 
phurince,  for  the  posterior  insert  ion -plate  is  well  developed.  The 


»    Ill/in    III  K.N. 

posterior  sinus,  however,  is  unlike  tin-  former  group,  in  which  the 

tail  valve  approaches  the  head  valve  in  form  ;  and  tin-  arrant ni'-nt 
of  the  eyes  is  (he  same  as  in  Lorir.i,  vvliidi  has  a  degenerate  tail 
in<ertion-plate.  At  the  same  time,  it  must  be  granted  tli at  tin-  differ- 
ences between  Si'hi:in'hif»n  and  Lnrim  a  re  greater  than  between  most 
genera  of  the  same  family;  for  in  Schizochiton  the  slits  of  the  head- 
valve  are  inimerieall y  related  to  the  external  ribs;  the  latter  bear 
and  the  tail  valve  has  a  well  developed  slit  and  pectinated 
insertion-plate. 

S.  iNviM's  Sowerby.     PL  51,  figs.  1-8. 

Shell  much  elongated,  narrow,  the  valves  elevated,  somewhat  car- 
inated  ;  surface  lusterless,  grayish,  obscurely  mottled  with  olive  and 
purplish. 

Median  valves  elongated,  beaked,  the  lateral  areas  small,  slightly 
raised.  Entire  surface  sculptured  with  flattened  longitudinal  ribletsr 
as  wide  as  their  interstices,  converging  toward  the  dorsal  ridge  and 
somen'hat  irregular  or  wavy  on  the  lateral  areas;  each  riblet  where  it 
passes  over  the  diagonal,  enlarged  for  the  insertion  of  an  eye.  Ante- 
rior valve  (figs.  2,  4)  having  6  (sometimes  7  or  8)  radiating  curved 
ribs,  each  bearing  a  series  of  eyes,  the  intervals  sculptured  with  close 
v-shaped  riblets.  Posterior  valve  (figs.  6,  7,  8)  having  the  mucro 
posterior,  the  latero-posterior  areas  tricostate,  otherwise  sculptured 
like  'the  median  valves  ;  posteriorly  it  has  a  wide,  deep  fissure,  extend- 
ing up  to  the  mucro  (fig.  8.) 

Interior  whitish,  stained  with  purple-brown  in  the  middle  of  each 
valve.  Sutural  plates  well  developed.  Sinus  V-shaped.  Anterior 
valve  having  6,  central  valves  1  or  2  slits;  posterior  valve,  on  each 
side  of  the  posterior  fissure,  3  slits  ;  teeth  thin,  distinctly  creii- 
ulated  outside. 

Girdle  broad,  alternately  buff  and  dark  colored,  the  light  stripes 
wider,  and  as  usual,  sutural ;  rather  thinly  but  in  places  densely 
clothed  with  minute,  cylindrical,  shelly  spinules,  part  brown,  part 
white.  Length  50,  breadth  18  mill. 

Zebu,  (Cuming),  and  Samboangan,  (Challenger),  Philip/tines; 
Raines  Island,  Torres  Straits  (Ince)  ;  Clairmout  <IH<!  Bird  Is., 
N.  E.  Australia  (Coppinger) ;  Sulu  Sea  (Capt.  Chimmo.) 

Chiton  incisus  SOWB.,  P.  Z.  S.  1841,  p.  61. — REEVE,  Conch.  Icon, 
f.  43.—Sehizochiton  liu-i^u*  GKAY,  P.  Z.  S.  1847,  p.  169.— SHUTTL., 
Bern.  Mittheil.  1853,  p.  68.— H.  &  A.  AD.,  Gen.  Rec.  Moll,  i,  p.  477, 


236  LORICA. 

t  54,  f.  6,  6a.— SMITH,  Zool.  Coll.  H.  M.  S. '  Alert '  p.  82.— HADDON, 
Challenger  Polyplac.  p.  31. — MOSELEY,  Journ.  Roy.  Microscop.  Soc. 
x  x  v,  p.  37,  pi.  iv,  figs.  1-5 ;  vi,  f.  5  (eyes). —  Chiton  elongatus  REEVE, 
Conch.  Icon.,  f.  40. — Schizoch-Uonpolyophtalmus  ROCHEBRUNE,  Bull. 
Soc.  Philomath,  de  Paris,  1881-'82,  p.  191. 

This  species  is  so  unlike  other  forms  that  comparisons  are 
unnecessary.  The  eyes  are  larger  than  in  any  other  form  known 
to  me.  A  single  eye  is  shown  in  fig.  3,  magnified  200  diameters. 

The  girdle  is  not  well  shown  in  fig.  1,  the  spines  being  too  evenly 
distributed  over  it.  They  are  always  closer  at  the  sutures. 

Genus  XVII.     LORICA  H.  &  A.  Adams,  1852. 

Lorica  H.  &  A.  Ad.,  Annals  and  Magazine  of  Natural  History, 
(2)  ix,  p.  355  (April,  1852).  Only  species  L.  cimolia,  Chiton  cimo- 
lius  RVE. — Aulacochiton  SHUTTL.,  Bern.  Mittheil.  p.  68  (June,  1853), 
type  Chiton  volvox  REEVE. 

Valves  exposed,  not  beaked,  the  lateral  areas  and  end  valves  with 
many  fine  riblets  or  pustules.  Eyes  confined  to  B  single  series 
along  the  summit  of  each  diagonal  rib.  Insertion-plates  blunt, 
obsoletely  pectinated,  the  slits  in  head-valve  not  corresponding  to 
external  ribs ;  sinus  very  small.  Posterior  valve  having  the  mucro 
posterior  and  terminal,  insertion-plate  unslit,  obsolete,  being  reduced 
to  a  convex  ridge  of  callus ;  posteriorly  cleft  to  the  mucro  by  a  deep 
rounded  sinus,  or  waved.  Girdle  slit  or  waved  behind,  densely 
scaly. 

This  is  one  of  the  few  genera  of  "  irregular  "  Chitons  having  a 
scaly  girdle.  The  eyes  seem  to  be  nearly  obsolete,  and  possibly  are 
not  functional,  although  they  still  are  pigmented.  In  most  spec- 
imens a  good  hand-lens  shows  the  series  of  ocular  punctures  along 
the  diagonal  ridge,  immediately  in  front  of  the  anterior  row  of 
pustules. 

The  non-correspondence  between  slits  and  external  ribs,  the  scaly 
girdle,  the  transverse,  unbeaked  valves  and  the  toothless  posterior 
insertion-plate,  are  all  characters  widely  sundering  this  genus  from 
Schizochiton. 

Section  Lorica  8.  str. 

Sinus  in  tail  valve  deep;  jugal  sinus  v-shaped;  girdle  widest  at 
the  sides,  cleft  behind. 


LOBIOA. 

I.  70LV03  Reeve,    IM.  52,  figs,  14-21. 

Shell  oblong,  strongly  elevated,  the  dorsal  ridge  anirular,  side- 
slopes  nearly  straight.  Surface  Insterless,  finely  sculptured,  variable 
in  color;  sometimes  hull' with  chestnut  streaks  and  darker  angular 
blotches  on  the  central  areas,  fewer  on  the  lateral  areas ;  sometimes 
the  lateral  areas  are  olive-green,  the  dorsal  region  light,  the  sides  of 
the  central  areas  brown  or  olive.  The  dorsal  ridge  is  sometimes 
staim •(!  with  orange  on  each  valve,  and  the  same  color  often  clouds 
the  sides  also. 

The  median  valves  are  not  beaked,  even  when  young,  but  they  are 
falsely  beaked  or  narrowly  projecting  at  the  sinus  in  front.  Lateral 
areas  raised,  sculptured  with  8-12  low  radiating  cords  bearing 
rounded  pustules,  which  are  more  or  less  entirely  lost  in  adult  spec- 
imens. Central  areas  sculptured  with  numerous  narrow  raised 
threads  parallel  to  the  dorsal  ridge,  their  interstices  wider  than  the 
threads,  and  closely  latticed  across.  Anterior  valve  strongly 
elevated,  curving  forward  at  the  summit,  the  anterior  slope  being  con- 
cave; sculptured  with  many  radiating  riblets  which  are  pustulose 
when  not  eroded.  Posterior  valve  small,  much  depressed,  with  pos- 
terior, terminal,  elevated  mucro ;  posterior-lateral  margins  bounded 
by  an  elevated  rib ;  posterior  area  extremely  small,  vertical, 
perpendicularly  ribbed,  having  a  deep  rounded  excavation  behind. 

Interior  white  ;  tegmentum  reflexed  and  sculptured  along  the  pos- 
terior margin  of  each  valve;  sutural-plates  broad,  separated  by  an 
extremely  small  v-shaped  sinus  in  the  middle.  Anterior  valve  hav- 
ing 8,  central  1  slit ;  slits  minute ;  teeth  short,  blunt,  finely  but 
obsoletely  pectinated  outside,  and  crenulated  on  the  edge.  Posterior 
valve  having  a  low,  rounded  callus  ridge  in  place  of  the  insertion- 
plate,  its  edge  unslit,  finely  and  rather  obsoletely  striated,  interrupted 
by  a  deep  rounded  sinus  in  the  middle  behind.  Eaves  narrow, 
solid. 

Girdle  wide,  bluish  with  inconspicuous  dusky  cross  bars,  slit 
behind,  its  surface  very  densely  covered  with  minute,  closely 
imbricating  smooth  convex  scales  (fig.  16.) 

Length  70,  breadth  38  mill. ;  divergence  about  90°,  the  young 
more  depressed. 

Port  Jackson,  Sydney,  Watson's  Bay  and  Middb  II<irl>or,  N.  S. 
Wales;  Port  Lincoln,  S.  Australia,  under  stones  at  extreme  low 
tide. 


238 

r/,/Vo/,  m/vn.r  JiKEvi-:.  Conch.  Icon.,  t.  6,  f.  31  (Feb.,  1847).— /,<>,- 
it-'t  i-ulrn.c  (Rve.)  IlAnimN,  'Challenger'  Polyplac.,  p.  31. —  Chiton 
cimol!".<  Hi: i:\  i :.  Conch.  Icon.,  t.  21,  f.  141  (May,  1847). — L 
rhnoli'i  \\.  &  A.  AD.,  Ann.  Mag.  N.  H.  (2)  ix,  p.  355. — ANGAS,  P. 
/.  S.  1SG7,  p.  224;  1871,  p.  97. — Aiilacochiton  volvox  SIIUTTL.,  Bern. 
Mittheil.  1853,  p.  68.—?  Chiton  nulls  HUTTON  (see  below.) 

The  differences  between  L.  volvox  and  L.  cimolia  are  easily  effaced 
when  a  good  series  is  examined.  The  yoilng  show  great  variation  in 
the  pustulation  of  the  lateral  areas,  the  pustules  sometimes  being 
scattered,  radiating,  cords  obsolete.  The  dorsal  ridge  generally 
has  a  central  fine  carina  with  a  long  narrow  smooth  triangle  on 
each  side,  but  this  varies  also.  The  second  valve  has  a  rather  large 
median  patch  of  scattered  or  diverging  series  of  pustules.  The  color- 
ing varies  a  good  deal  in  the  series  before  me. 

'  I  am  disposed  to  consider  Hutton's  Chiton  rudis  a  synonym  of 
this  species,  but  my  opinion  is  founded  upon  a  study  of  the  original 
description  only,  which  is  as  follows : 

Chiton  rudis  Hutton.  Oblong;  margin  with  minute  scales; 
valves  elevated,  flattened  on  the  sides,  not  keeled  ;  apex  of  anterior 
valve  recurved,  with  its  posterior  margin  slightly  convex  at  the  sides 
and  deeply  concave  in  the  center ;  posterior  margins  of  intermediate 
valves  straight ;  posterior  valve  rather  small ;  apex  posterior,  pointed 
and  emarginate.  Anterior  valve  and  lateral  areas  with  radiating 
moniliform  ribs ;  posterior  and  median  areas  widely  but  rather  irreg- 
ularly, deeply  longitudinally  furrowed,  with  narrow  ridges  between 
Margin  gray,  with  broad,  irregular,  reddish-brown  transverse 
patches;  valves  grayish-brown  ;  interior  grayish-white.  Length  1*75, 
breadth  '75  inch.  Founded  on  a  specimen  in  the  Colonial  Museum, 
locality  not  stated.  (Hutto.i,  in  Trans.  N.  /,-  Inst.  iv,  1872,  p.  179, 
and  Man.  N.  Z.  Moll.  1880,  p.  113.) 

Section  Loricelli  Pilsbry. 

Sinus  in  tail  valve  a  mere  wave  ;  jugal  sinus  lobed  ;  girdle  widest 
in  front,  not  cleft  behind. 

L.  \\<. AM  Adam-  and  Angas.     PI.  ~>1,  figs.  9-13. 

Shell  ovate,  coarctate  and  angulate  behind,  pale  brown,  variegated 
with  green.  Anterior  valve  concentrically  striated  and  having 
radiating  pustulose  ribs  ;  posterior  valve  narrow,  transversely  silicate 
and  densely  longitudinally  lirate;  median  valves  subcarinated,  the 


central  arras  driiM-ly  lirat»-  and  t  ran.-vi-r-rl y  siilraH-d;  tli.-  lateral 
area-  elevated,  radially  lirate,  tin-  line  jmst  ulose. 

(iirdle  moderate,  nlivaeemi-,  L-sct  with  minute  scales. 

Leii-th   H>.  luva.lth  I'll  mill.     <  If.  .!</.  <t  Any.) 

Rcij>i<l  J»<ii/,  \  An.-fi'iilin  (Angaa);  Camp  ('<><-,•,  /'„,-/  ./<"•/. vo>,,  N. 
S.  I  !",//,•.>•  llra/ier).  In  deep  water. 

Lorica angati  II.  AD.  <fe  ANG.,  I*.  7.  S.  1864,  p.  193. — ANOAS, 
1865,  p.  is;  ;  1S71,  p.  97.—Aul«r,,rJn't<,,,  angasi  CI-K.,  .)/>. 

I  have  not  seen  this  species,  which  is  here  figured  for  the  first 
time,  from  drawings  made  by  Emerton  for  Carpenter,  who  writes  as 
follows : 

"  Anterior  valve  large ;  posterior  valve  small,  the  mucro  terminal, 
much  elevated,  prominent ;  diagonal  ridges  elevated  ;  dorsal  ridge 
acute.  Interior  :  posterior  valve  a  little  sinuated  behind,  the  sinus 
wide;  having  two  callous,  subobsolete,  slightly  roughened  ribs  in  place 
of  the  insertion-plates.  Anterior  valve  with  10,  central  valves  1 
slit ;  teeth  acute,  serrated  outside  and  at  the  edge  ;  eaves  prominent, 
deeply  grooved ;  sinus  narrow,  deep ;  the  sutural  plates  separated, 
but  having  a  lamina  between  them  which  is  sometimes  bilobate  or 
denticulate.  Girdle  reduced  one-half  in  width  behind,  and  sinuated, 
very  closely  beset  with  solid  minute  scales,  seen  under  a  lens  to  be 
obsoletely  bilobate. 

Length  32£,  breadth  22J  mill, ;  divergence  110°. 

"  One  of  Mr.  Cuming's  specimens  is  much  broader  and  somewhat 
tripartite.  This  species  differs  from  the  typical  Lorica  in  the  anterior 
projection  of  the  girdle  ;  in  the  minute  raised  scales,  which  under  the 
microscope  look  like  grains  of  wheat  set  on  end  ;  in  the  sinus  having 
a  separate  lamina,  somewhat  lobed  ;  in  the  absence  of  anterior  *  false 
apex '  on  the  valves ;  and  finally  in  the  mucro  being  terminal  and 
but  slightly  waved,  with  a  correspondingly  slight  wave  in  the  girdle 
behind." 

The  "  hairs  "  shown  on  the  girdle  in  fig.  9  are  foreign  to  it. 

Genus  XIX.     LIOLOPHURA  Pilsbry,  1893. 

Liolophura  PILS.,  The  Nautilus  vi,  j>.  105  (January,  1893). — 
Acanthopleura  sp.,  of  authors. 

Valves  exposed,  dull  and  somewhat  roughened,  irenerally  erodrd 
outside,  with  minute  eyes  irregularly  scattered  over  the  lateral  i 
the  head-valve  and   the  sides  of  the  central  areas.      Interior  dark 


240  LIOLOPHURA. 

colored,  having  anterior  and  side  insertion-plates  slit  into  teeth  and 
sharply  pectinated  outside  ;  posterior  valve  with  posterior  terminal 
mucro,  lacking  the  insertion-plate,  which  is  represented  by  a  flat 
callous  ledge.  Sinus  wide,  deep,  smooth. 

Girdle  covered  with  stout  calcareous  spines  or  obtuse  club-shaped 
processes.  Type  Chiton  japonicua  Lischke. 

The  species  of  this  genus  have  been  referred  to  Acanthopleura, 
Mmiyrin  and  Chiton  by  authors  who  have  mentioned  them;  but 
from  these  groups  the  characters  of  the  tail-valve  at  once  sunder 
them.  Liolophura  resembles  Onithochiton  and  Enoplochiton  in  hav- 
ing a  callous  ridge  in  place  of  the  posterior  insertion-plate,  in  the 
pectinated  teeth  of  the  other  valves,  and  in  the  possession  of  eyes ; 
but  it  differs  from  Onithochiton  (a)  in  the  somewhat  rawed  instead  of 
marginal  mucro,  (b)  in  the  dullness  of  the  valves  externally,  (c)  in 
the  distribution  of  the  eyes  upon  the  sides  of  the  central  areas,  whilst 
in  Onithochiton  they  occupy  a  band  on  the  forward  part  of  the  lateral 
areas  only ;  and  finally  (d)  in  the  covering  of  the  girdle  which  in 
Liolophura  consists  of  densely  crowded  calcareous  spines,  comparable 
to  the  spines  of  Maugeria.  Liolophura  differs  from  Enoplochiton  in 
lacking  the  interior  sculpture  and  denticulate  sinus  characteristic  of 
that  genus,  and  in  the  totally  diverse  development  of  the  girdle 
covering. 


L.  GAIMARDI  Blainville.     PL  53,  figs.  30-35. 

Shell  oblong,  depressed,  roundly  arched.  Surface  lusterless,  buff- 
gray,  marked  at  sides  and  on  ridge  of  valves  with  black.  Girdle 
tessellated  light  and  dark,  having  a  light  bar  opposite  each  suture, 
or  having  dark  or  light  larger  patches. 

The  valves  are  somewhat  beaked,  but  always  considerably  eroded  ; 
lateral  areas  but  little  raised,  concentrically  wrinkled  toward  their 
bases,  studded  with  minute  scattered  eyes  appearing  as  black  dots. 
Central  areas  wrinkled  by  lines  of  growth  and  having  scattered  eyes 
at  the  sides.  Head  valve  concentrically  wrinkled,  studded  with 
eyes.  Tail  valve  small,  depressed,  similar  in  contour  to  the  median 
valves,  the  mucro  being  posterior  and  terminal,  but  eroded. 

Interior  dark  red-brown,  whitish  on  the  edges  of  the  sutural-plates 
and  the  valve-callus;  posterior  internal  margin  covered  by  the 
reflexed  blackish-brown  tegmentum.  Sutnral-plates  brownish  below 
with  a  white  outer  edge ;  seen  from  above  they  are  whitish  shading 
into  reddish-brown  toward  the  median  sinus;  rounded,  broadly 
separated  by  a  very  wide,  deep,  rounded  sinus.  Anterior  valve  hav- 


i  KM  oi'HtjRA.  241 

ing  9,  central  valves  1  slit  :  the  teeth  deeply,  el.xely  pertinatrd  out- 
side. Posterior  valve  having  the  eaves  projecting  beyond  the  l.road, 
flat  crescent  of  callus  which  occupies  the  place  of  an  insertion-plate. 

( Jirdle  densely  clothed  with  intermingled  minute,  larger  and  large 
calcareous  spines,  (fig.  31.) 

New  tiouth  Wales  (Wilkes)  ;  Port  Jackson  (Blainville,  Coppinger 
and  Challenger  Kxped.  >  Australia. 

Chiton  incanns  GOULD,  Proc.  Bost.  Soc.  Nat.  Hist.  1846,  ii,  p.  145  ; 
U.  S.  Expl.  Exped.,  p.  315,  t.  28,  f.  432, 432a ;  Otia,  p.  6.— Maugeria 
invtnus  GLD.,  Otia,  p.  248. — Acanthopleura  incana  E.  A.  SMITH, 
Zool.  Coll.  H.  M.  S. '  Alert,'  p.  81, 1884.—?  Chiton  piceu*  ANGAS,  P. 
Z.  S.  1867,  p.  223.—Acanthopleura  (/)  incana  (Old.)  HADDON, 
Challenger  Polyplac.,  p.  25  (in  part.) — Chiton  gaimardi  BLAINV., 
Diet.  Sc.  Nat.  xxxvi,  p.  546,  (1825.) 

This  species  may  readily  be  separated  from  all  forms  of  Acantho- 
pleura by  the  peculiar  flat  callus  of  the  tail  valve  inside,  altogether 
lacking  the  pectination  and  slits  which  are  present  in  Acanthopleura. 
It  differs  also  in  having  eyes  scattered  over  the  sides  of  the  lateral 
areas,  and  in  having  some  of  the  girdle-spines  striated.  It  differs 
from  the  Japanese  species  in  the  differently  colored  interior  and 
sutural-plates,  in  the  details  of  girdle-structure,  etc. 

The  spines  on  the  white  tracts  of  the  girdle  are  unicolored  whitish  ; 
on  the  dark  tracts  they  are  of  a  uniform  black-brown  color.  Occa- 
sional spines  are  striated  like  the  scales  of  Ischnochiton. 

L.  GEORGIANA  Quoy  and  Gaimard.     PI.  53,  figs.  36-40. 

Body  oval,  thick ;  girdle  narrow,  granulose,  whitish  with  8  white 
stripes;  valves  arcuate,  flattened,  thickly  striated  ;  brown,  black  in 
the  middle. 

The  body  is  short,  oval,  much  swollen  ;  girdle  very  thick,  little 
dilated  at  the  sides,  covered  with  very  small  rounded  tubercles,  white 
with  8  black  bands  across  each  side.  Foot  narrow,  yellowish. 
Branchiae  reaching  to  the  buccal  fringe,  which  is  large.  Valves 
very  wide,  covering  nearly  the  whole  body,  semicircular,  but  little 
elevated,  narrowed,  somewhat  heart-shaped,  very  thick ;  having 
concentric  striae,  the  anterior  and  lateral  most  marked;  of  a  deep 
brown  color  at  the  sides,  lighter  in  the  middle  with  a  black  dorsal 
line ;  fourth  and  fifth  valves  equal  and  wider  than  the  others. 
Inside  the  valves  are  of  a  violaceous  brown  ;  median  valves  with  an 
arcuate  thickening.  The  sutural  plates  are  short,  rounded,  separated 
by  a  flat,  straight  median  sinus.  Insertion  plates  slit  and  crenulated. 
16 


242  LIOLOPHURA. 

Anterior  valve  having  12  to  15  short,  unequal,  deeply  striated  teeth. 
Posterior  valve  triangular,  flattened,  with  a  callus  in  place  of  the 
insertion-plate.  All  of  the  apophyses  (which  are  of  a  horny  color) 
have  a  brown  spot  at  the  angle. 

Length  19  lines,  breadth  1  inch.     (Q.  &  <?.) 

King  George  Sound,  S.-W.  Australia  (Port  du  Roi-Georges.) 

Chiton  georgianus  Q.  &  G.,  Voy.  de  1'Astrol.,  Zoologie,  iii,  p.  379, 
t.  75,  f.  25-30. 

This  species  is  apparently  still  unknown  in  English  and  Amer- 
ican collections.  It  seems  to  resemble  closely  the  L.  incana  of  New 
South  Wales,  but  differs,  if  we  may  trust  Quoy's  account,  in  the 
much  shorter  girdle  appendages,  which  resemble  "  rounded  tuber- 
cles "  rather  than  unequal  spines.  The  figure  of  a  detached  valve 
given  by  Quoy  shows  a  forward  wave  of  the  tegmentum  at  the 
median  sinus,  more  prominent  than  in  any  incamis  before  me,  which 
scarcely  show  such  a  wave  except  on  the  second  valve.  The  median 
valves  of  Enoplochiton  niger,  however,  present  an  exactly  similar 
sinuosity  of  the  margin  (compare  figs.  24,  25,  of  pi.  52).  The  sinus, 
moreover,  appears  in  Quoy's  figures  to  be  bridged  by  a  lamina  con- 
necting the  sutural  plates,  a  condition  which  does  not  obtain  in  L. 
incana.  It  is  possible  that  the  small  variety  mentioned  by  Quoy  is 
more  closely  allied  to  the  incana,  or  identical  with  it. 

L.  CURTISIANA  Smith.     PI.  24,  fig.  6. 

I  am  disposed  to  believe  that  CHITON  CURTISIANUS  Smith,  which 
is  described  on  p.  97  and  illustrated  on  pi.  24,  fig.  6  (figure  enlarged 
and  inverted),  is  a  member  of  this  genus;  but  as  Smith  called  it  an 
Ischnochiton,  I  included  it  in  that  genus  provisionally. 

L.  JAPONICA  Lischke.    PL  53,  figs.  41,  42,  43,  44. 

Shell  oblong,  moderately  elevated,  arched,  not  carinated.  Surface 
lusterless,  generally  much  eroded  and  encrusted  ;  blackish,  generally 
showing  a  wide  light  stripe  on  each  side  of  the  black  dorsal  stripe  ; 
the  wide  girdle  olivaceous,  not  distinctly  barred. 

The  median  valves  are  beaked;  lateral  areas  hardly  raised,  sculpt- 
ured with  concentric  growth-wrinkles  and  a  minute  granulation, 
often  lost  by  erosion.  Central  areas  similarly  sculptured.  Thefonvnnl 
half  or  two-thirds  of  the  lateral  areas  and  the  outer  portion  of  the 
central  areas  is  black-dotted  by  the  numerous  irregularly  scattered 
eyes.  Anterior  valve  sculptured  like  the  lateral  areas  and  closely 
studded  with  scattered  black  dots  (eyes).  Posterior  valve  depressed, 


243 

the  miiero  posterior  and  terminal,  UMIIL:  produced  l.evond  and  above 
the  p<Meri..r  oaves. 

Interior  black.  The  sutural  plates  an-  Mack  both  outside  and 
within,  and  an-  widely  separated  by  a  broad,  deep,  rounded  *inu~. 
Head-valve  with  8,  9  or  10,  median  valves  1  slit;  teeth  short  in 
front,  longer  at  the  sides,  deeply  pectinated  outside.  Posterior 
valve  having  a  broad  flat  crescentic  callus  in  place  of  the  insertion- 
plate. 

Girdle  very  broad,  densely  clothed  with  short,  obtuse  black-brown 
spines,  tipped  with  whitish  (fig.  43.) 

Length  50,  breadth  20  mill,  (measurements  not  including  girdle.) 

Japan,  at  Enoshima  (F.  Stearns)  ;  Oosima  ('  Challenger ')  ;  Nag- 
asaki (Lischke.) 

Chiton  japonicus  LISCHKE,  Malak.  Blatter,  xxi,  p.  22  (June, 
1873)  ;  Japonische  Meeres-Conchylien  iii,  p.  71,  t.  5,  f.  8-11. — 
Maugeria  japonica  DKR.,  Index  Moll.  Mar.  Jap.,  p.  158. — Acantho- 
pleura  (/)  incana  HADDON  (in  part),  Challenger  Polyplac.,  p.  25. 
Not  Ch.  inconus  Gould. —  Ormthochiton  caliginosus  CPR.,  MS.  (spec- 
imen described  from  China.) 

?  Chiton  De  Filippii  TAPPARONE  CANEFRI,  Zool.  del  Viaggio 
intorno  al  Globo  del  la  R.  Fregata  '  Magenta,'  Malacol.,  p.  77, 
1874. 

Distinguished  from  L.  incana  by  the  uniform  black  color  of  the 
inner  layer  or  articulamentum. 

The  typical  japonica  (pi.  53,  figs.  41-44)  has  a  broad  girdle, 
•densely  clothed  with  spinelets  which  are  nearly  or  quite  cylindrical, 
and  are  about  equal  in  size  over  the  entire  area  of  the  girdle.  There 
are  usually  some  dusky  bars,  especially  toward  the  ends ;  and 
the  individual  spinelets  are  dark  brown,  tipped  with  light  brown 
or  cream-white. 

Var.  tessellata  Pils.  (pi.  53,  figs.  45,  46)  includes  specimens  agree- 
ing with  the  type  in  valve  structure  and  coloring,  but  having  the 
girdle  much  narrower,  and  conspicuously  varied  with  alternate 
patches  of  white  and  scorched-brown  or  blackish.  The  individual 
spinelets  are  larger  than  in  typical,/"/"""'"'  Iinc^  vary  much  in  size, 
being  small  toward  the  outer  edge  of  the  girdle,  large  and  flattened 
toward  the  inner  edge.  Upon  the  light  tracts  the  spine?  are  uni- 
colored  white  ;  upon  the  dark  tracts  they  are  reddish-brown  or 
blackish,  unicolored  or  tipped  with  lighter. 


L'4-l  ONITHOOHJTON. 

Specimens  collected  by  Stearns  are  before  me,  from  Enoshima, 
where  the  typical  form  also  is  found. 

The  type  of  Carpenter's  unpublished  Ornithochiton  (/)  caliginosus 
is  shown  in  figures  41-45  of  pi.  54.  It  was  described  from  specimens 
in  the  Cuming  collection  from  "  China  Seas,"  and  C.  B.  Adams 
collection  from  Hongkong.  I  have  no  doubt  of  its  identity  with 
the  L.  japonica.  The  latter  had  not  been  published  at  the  time 
Carpenter  wrote  his  diagnosis. 

Tapparone  Canefri's  note  on  Ch.  defilippii  is  not  sufficiently  clear 
for  me  to  quote  it  without  the  mark  of  interrogation  ;  for  he  com- 
pares with  a  species  from  Sydney  which  he  calls  Chiton  piceus  Gmel. 
But  although  he  refers  to  Reeve,  fig.  70,  I  am  disposed  to  believe 
from  his  text,  that  what  he  really  had  from  Sydney  was  lAolophura 
incana  Old.  In  this  case,  there  can  be  little  doubt  that  his  defilippii 
is  a  synonym  of  L.  japonica. 

L.  LOOCHOOANA  Broderip  &  Sowerby. 

Valves  subscabrous,  the  marginal  areas  radially  granose.     Girdle 

leathery,  granose  above,  the  grains  elevated.     Length  18J,  breadth 

7|  mill.     A  very  pretty  little  Chiton,  whose  margin  is  covered  with 

small  grains,  resembling  very  short,  blunt  spines.     (Brod.  &  Sowb.) 

Shore  of  Loo  Choo  Is.  (Belcher,  Mus.  Zool.  Soc.  Lond.) 

Chiton  loo-chooanus  BROD.  &  SOWB.,  Zool.  Journ.  iv,  p.  368  (Oct. 
1828— Jan.,  1829.) 

This  species  is  absolutely  unrecognizable  by  the  above  descrip- 
tion, but  it  was  perhaps  a  member  of  the  genus  Liolophura  which 
the  authors  had  before  them.  It  is  not  mentioned  or  illustrated  in 
the  "  Zoology  of  Captain  Beechey's  Voyage."  See  Gray's  reference 
to  these  descriptions  in  the  "  Introductory  Remarks,"  Zool.  Beechey's 
Voy.,  p.  103. 

Genus  XIX.     ONITHOCHITON  Gray,  1847. 

Onithochiton  GRAY,  P.  Z.  S.  1847,  p.  65, 6S.—  Onythochitont  GRAY, 
/.  c.,  p.  169  (type  Ch.  undulatus) ;  Guide  Syst.  Dist.  Moll.  B.  M.,  p. 
184.—  Ornithochiton  CPR.,  in  Dall,  Proc.  U.  S.  Nat.  Mus.  1881, 
p.  284. 

Valves  exposed,  polished,  beaked,  with  indistinct  lateral  areas ; 
eyes  present  and  disposed  in  a  ray  on  the  forward  part  of  each 
lateral  area  and  in  numerous  rays  on  the  anterior  valve.  Interior 
porcellanous ;  sinus  denticulate,  angular ;  insertion-plates  pectinated 


i.NI  I  II'"    Illl 

outside,  tliat  of  tin-  first  valve  with  N  slits,  median  valves  1  slit;  pos- 
terior valve  depressed,  triangular,  with  posterior  terminal  and  mar- 
ginal inurro,  the  insertion-plate  reduced  to  a  low,  smooth  and  narrow 
callus.  Girdle  leathery,  rendered  velvety  by  very  minute  chaffy 
hairs.  Type  0.  umfn/afnn  Quoy. 

This  genus  resembles  Enoplochiton  and  Liolopkura  in  the  char- 
acters of  the  tail  valve.  It  differs  from  the  former  in  the  unsculpt- 
nred,  porcellanous  interior,  much  more  delicate  structure  of  the  tail- 
valve  callus  and  different  type  of  girdle.  Onithochiton  differs  from 
LiolopJwra  in  the  texture  both  inside  and  out,  the  very  different 
arrangement  of  the  eyes,  more  delicate  tail-valve  callus,  and  in 
the  characters  of  the  girdle. 

The  species  are  distributed  from  the  Cape  of  Good  Hope  to  New 
Zealand. 

Carpenter  emended  the  name  to  "  Ornithochiton  "  believing  it  to 
be  derived  from  ornis,  ornithos,  in  allusion  to  the  resemblance  of 
single  valves  to  the  conventional  representation  of  a  bird  on  the 
wing ;  but  if  any  Greek  root  was  in  Gray's  mind  it  was  probably 
Onychochiton  rather  than  Ornithochiton. 

Key  to  species  of  Onithochiton. 

a.  Lateral  areas  and  anterior  valve  smooth  or  radially  sculptured ; 
central  areas  smooth. 
b.  Lateral  areas  smooth  or  with  4  or  5  low  subgranose  riblets, 

undulatns. 
bb.  Lateral  areas  closely  sculptured  with  close,  subgranose  striae, 

semisculptus. 

-aa.  Lateral  areas  having  concentric  sculpture ;   central   areas  or 
pleura  with  for  wardly-con  verging  sulci.  ' 

b.  Length  of  posterior  valve  from  sinus  to  mucro  distinctly  less 
than  half  the  valve's  breadth,    lyellii,  quercinus,  rugulosus, 

[amicorum. 

bb.  Length  of  posterior  valve  from  sinus  to  mucro  half  the  valve's 
breadth. 

c.  Valves  having  a  smooth  dorsal  triangle,  maillardi. 

cc.  Valves  having  zigzag  sculpture  over  the  ridge,         literatus. 


O.  UNDULATUS  Quoy  &  Gaimard.     PI.  55,  figs.  14,  15,  Hi. 

Shell  oblong,  moderately  elevated,  the  dorsal  angle  rounded,  side- 
slopes  nearly  straight.     Surface  polished  ;  color  either  (1)  olive-buff 


246  ONITHOCHITON. 

or  olive-gray,  becoming  yellow  toward  the  apices  of  the  valves,  each 
valve  elegantly  painted  throughout  with  concentric  olive  or  brown 
lines,  and  having  a  darker  dorsal  band  ;  or  (2)  olive-green  at  the 
sides,  with  a  broad  light  triangle  on  the  ridge  of  each  valve,  in  the 
middle  of  which  there  is  a  stripe  of  rich  chestnut  or  of  green  ;  the 
whole  concentrically  lineolate  with  irregular  green  and  cream-white 
lines. 

The  valves  are  beaked  ;  lateral  areas  but  little  raised,  and  either 
smooth  or  sculptured  with  4  or  5  low,  more  or  less  obsolete,  beaded 
radiating  riblets ;  and  showing  under  a  lens,  a  band  of  eye-dots  near 
the  front  margin.  Central  areas  smooth  and  polished.  Anterior 
valve  having  obsolete  radiating  riblets,  and  rays  of  eyes,  the  eye- 
rays  variable  in  number,  width,  and  degree  of  coalescence,  the 
individual  eyes  being  very  mutable  in  number  and  position.  Pos- 
terior valve  very  shortly  subtriangular,  the  distance  from  sinus  to 
mucro  being  but  little  more  than  one-third  the  width  of  the  valve's 
tegmentum. 

Interior  white,  marked  with  reddish-brown  under  the  beak  in  each 
valve.  Sinus  delicately  toothed,  deep  and  angular;  sutural-plates 
higher  toward  the  sinus  than  toward  the  outer  edges  of  the  valves- 
Anterior  valve  having  8  slits,  median  valves  1  slit ;  teeth  obtuse, 
closely  and  sharply  pectinated  outside  and  on  the  summits.  Poste- 
rior valve  having  a  narrow,  slightly  convex  ridge  in  place  of  the 
insertion  plate. 

Girdle  reddish  or  brown. 

Length  25,  breadth  16  mill. ;  divergence  110°. 

Length  27,  breadth  14  mill.;  divergence  110°. 

New  Zealand,  at  Bay  of  Islands  (Q.  &  G.) ;  Auckland  to  Dunedin 
(Hutton)  ;  Chatham  Is.  (Hutton.) 

Chiton  undulatus  Q.  &  G.,  Zool.  Astrolabe,  p.  393,  t.  75,  f.  19-24. 
— REEVE,  Conch.  Icon.,  t.  16,  f.  87,  90. —  OnitliocMton  undulatus 
ADS.,  Genera,  i,  p.  476,  t.  54,  f.  3. —  Tonicia  mtdulutn  HUTTON, 
Man.  N.  Z.  Moll.,  p.  114  (1880.; 

The  comparative  breadth  of  this  species  is  subject  to  considerable 
mutation,  as  well  as  the  coloring  and  the  development  of  weakly 
beaded  riblets  on  the  lateral  areas.  In  some  specimens  these  riblets 
are  not  perceptible.  Occasionally  the  sides  of  some  valves  are  uni- 
form greenish,  lacking  brown  lines  and  angular  white  lines. 

This  species  has  been  reported  from  Tasmania,  but  on  insufficient 
authority. 


oun  ii<"  m TON.  - 17 

Tin-  sculpture  in  this  form  differs  markedly  from  the  Au-t ralian 
and  S.  AtViean  species. 

O.  SEMI8CULPTU8  I'ilshrv,  n.  sp.       PI.  f,f),  figs.  10,  11. 

Sliell  oblong,  elevated,  subangular,  dark  olive-green,  having  snowy 
angular  lines  and  dots  on  the  lateral  areas,  and  closer,  more  regular 
transverse  lines  on  central  areas.  Surface  shining  and  xmooth  onthe 
central  ureas,  closely  and  finely  striated  radially  on  the  head  valv 
/<tt<  ral  areas,  the  *trin-  crowded  and  subyranose,  about  12  in  number 
on  each  lateral  area.  Interior  white.  Girdle  narrow,  brown. 

Length  27 J,  breadth  16  mill.;  divergence  about  95°. 

Habitat  un J: ic > a  a. 

This  species  resembles  the  stout,  elevated,  dark  olive  forms  of  0. 
nmlnlatus,  such  as  occur  at  Auckland,  N.  Z.,  in  contour  and  colora- 
tion. It  differs  markedly  from  undulatus  and  all  other  known 
species  in  t<he  sculpture  of  the  lateral  areas. 

Figure  10  shows  two  half  valves,  the  upper  illustrating  the  color- 
pattern,  the  lower  the  sculpture. 

O.  LYELLII  Sowerby.    PL  55,  figs.  1-7. 

Shell  oblong,  moderately  elevated,  the  dorsal  ridge  rounded  or 
slightly  subangular.  Color  extremely  variable  ;  typically  green  at 
the  sides,  with  a  tessellated  black  or  chestnut  dorsal  stripe  in  the 
middle  of  a  pink-dotted  area  ;  but  other  specimens  are  blotched  with 
green  at  the  sides  with  concentric  creamy  lines  and  a  creamy  area  on 
the  ridge  of  each  valve,  along  which  runs  a  band  of  dark  chestnut 
spots  often  on  a  bluish  ground.  Occasional  specimens  have  a  large 
black  blotch  on  the  sides  of  some  valves. 

The  median  valves  are  beaked.  Lateral  areas  a  trifle  raised, 
sculptured  with  rather  uneven  concentric  shallow  grooves  with  rather 
wide,  flat  interspaces  ;  near  the  front  edge  of  each  lateral  area  there 
is  a  narrow  band  of  minute  eye-dots.  Central  areas  scut]>tnr«l  at 
the  sides  with  fine,  close  grooves  (continued  from  those  of  the  lateral 
areas)  converging  toward  the  ridge,  where  there  is  a  narrow  smooth 
dorsal  band.  Anterior  valve  having  about  10  narrow  rays  of  eyes, 
the  spaces  between  sculptured  with  concentric  grooves  interrupted 
by  the  eye-bands  into  scallops  having  their  convexity  upward, 
terior  valve  broadly  triangular,  depressed. 

Interior  white  with  a  crimson  spot  in  the  cavity  of  each  valve. 
Sinus  deep,  angular,  delicately  subdenticulate.  Anterior  valve  hav- 
ing 8,  median  1  slit ;  the  teeth  rather  long,  sharply  pectinated  out- 


248  ONITHOCHITON. 

side.  Posterior  valve  having  a  smooth  callus  in  place  of  the  inser- 
tion-plate, separated  from  the  eaves  by  a  groove  at  each  side. 

Girdle  leathery,  closely  clothed  with  microscopic  down,  clouded 
brown  and  whitish. 

Length  42,  breadth  20  mill. 

Pitcairn  Island,  in  small  hollows,  at  low  water  mark  (Cuming) ; 
Raine's  Island,  Torres  Ste.,  under  stones  at  low  water  (Ince)  ;  Wat- 
son's Buy,  N.  S.  Wales,  Australia,  at  very  low  tides  (Angas.) 

Chiton  lyellii  SOWB.,  P.  Z.  S.  1832,  p.  26 :  Conch.  Illustr.  f.  7.— 
REEVE,  Conch.  Icon.,  f.  12. —  Chiton  incii  REEVE,  Conch.  Icon- 
no.  94,  t.  16,  f.  96 ;  detail  fig.  94. — Chiton  puncticulatus  REEVE, 
Conch.  Icon.,  t.  13,  f.  696  and  description  in  part — Onithochiton 
incei  ANG.,  P.  Z.  S.  1867,  p.  223. 

This  species  differs  from  O.  maillardi  in  the  narrower  smooth 
dorsal  areas,  the  less  deep,  less  regular  grooving  of  the  lateral  areas, 
and  the  shorter  and  broader  posterior  valve.  It  relations  to  the 
following  species  are  not  clear  to  me,  as  I  have  seen  no  authentic 
specimen  of  the  latter. 

Figs.  8,  9  of  pi.  55  represent  the  C.  incii  of  Reeve. 

The  Chiton  puncticulatus  of  Reeve  seems  to  have  been  founded  on 
a  specimen  of  this  species  and  one  of  Pallochiton  lanuginosus ;  but 
Reeve's  reference  to  the  punctation  seems  to  apply  best  to  this  form. 
In  any  case,  the  name  is  so  ill-defined  that  it  cannot  in  fairness  be 
used. 

O.  QUERCINUS  Gould.     PI.  55,  figs.  12, 13. 

Shell  small,  depressed,  slightly  carinateand  beaked,  ovate,  yellow- 
ish wood  or  oak  color,  clouded  with  olive  or  dusky  slate  color  at  the 
sides.  Lateral  areas  scarcely  raised,  but  distinctly  marked  by 
coarse  longitudinal  sulci,  which  are  divided  by  a  radiating  furrow 
and  sometimes  more,  and  the  two  portions  form  somewhat  of  an 
angle  with  each  other;  central  areas  with  faint,  rugose,  longitudinal 
lines  toward  the  margin,  and  scattered  punctures  about  the  apex  ; 
anterior  valve  checked  with  raised  spaces  formed  by  concentric  and 
more  distant  radiating  furrows,  which  become  more  numerous  near 
the  margin  ;  posterior  valve  with  theumbo  nearly  terminal,  so  that 
the  transverse  ridge  runs  nearly  parallel  to  the  margin.  Marginal 
ligament  broad,  yellowish,  frosted.  (Old.) 

Length  22,  breadth  15  mill. 

New  South  Wales,  Australia. 


i .  N 1 1 1 1  • M  •  1 1 1 1  249 

Chiton  quern' n n<  «.M...    Pro<  Nut.    Hi-t.   ii,   p.    ML' 

(1846);  U.  S.  Expl.    Erped   M.,11.,  p.  .'{12,  f.  437,    1870;  <>ti:i 
Conch.,  p.  3. —  C.  (f)nitlnn'hitnn)  >jii'  GH  i'.  ()tiji,  p.  -42. 

Closely  allied  to  0.  /y<  ///  and  O.  /•»/;/ "fosus. 
O.  RuouLoeuB  Angas.     1M.  :>:>,  fig.  19. 

Shell  elougately  ovate,  a  little  narrowed  in  front,  raised  and  car- 
inated,  pale  yellowish-brown,  the  central  areas  of  the  valves  faintly 
spotted  with  olive,  the  outer  edges  bordered  with  green,  upon  which 
and  extending  inward  are  concentric  waved  bands  of  olive  brown 
darker  at  the  margin;  lateral  areas  not  raised,  divided  from  the 
dorsal  areas  by  radiating  nodulous  ribs,  transversely  rugosely,  costate  ; 
dorsal  areas  finely  longitudinally  ridged ;  mantle  brown,  variegated 
with  ash-color  and  clothed  with  very  minute  chaff-like  scales- 
(Aug.)  Length  16  mill. 

Port  Jackson,  Australia. 

Onithnclnton  rugnlosns  ANG.,  P.  Z.  S.  1867,  p.  115,  223,  t.  13, 
f.  29. 

Carpenter  gives  the  following  notes  upon  the  type  specimen  : 
Shell  broad,  the  valves  much  beaked,  dorsal  ridge  acute.  Mucro 
terminal.  Jugal  area  scarcely  distinct,  smoothish ;  central  areas 
having  about  16  nearly  longitudinal,  jagged  wrinkles,  nearly  meet- 
ing over  the  jugum.  Lateral  areas  very  sharply  rugose,  much 
more  so  than  in  the  other  species,  the  rugse  about  12,  not  developed 
in  young  shells,  very  irregular,  swelling  into  granules  especially  «>n 
the  diagonal  lines  and  sutures.  Anterior  valve  having  8  lines  of 
black  dots,  with  two  additional,  indistinct  ones.  Inside  whitish  with 
a  brown  spot  in  the  cavity  ;  posterior  valve  having  the  mucro 
absolutely  terminal,  the  insertion-plate  planed  off.  Anterior  valve 
having  8  slits;  teeth  very  finely  rugose;  sinus  deep,  flat,  tolerably 
broad,  with  about  20  fine  teeth.  Girdle  covered  with  minute  hairs. 

Length  16$,  breadth  12  mill.;  divergence  125°. 

O.  AMICORUM  Baird.     PL  54,  fig.  46. 

Shell  rather  elongated,  elevated,  with  acute  dorsal  ridge.  There 
is  a  line  of  reddish-brown  color  along  the  dorsal  ridge,  and  one  or 
two  others  along  the  sides. 

Lateral  areas  much  elevated,  with  very  nodulous  wrinkles,  two  or 
three  irregularly  concentric ;  these  are  partly  on  the  diagonal  and 
sutural  ribs,  with  others  intercalated.  Central  areas  with  about  '2'2 
slightly  irregular  riblets,  nearly  longitudinal,  but  bending  toward  the 


250  ONITHOCHITON. 

middle,  the  interstices  very  narrow.  Anterior  valve  having  about 
20  radii,  much  smaller  than  those  of  the  lateral  areas,  but  toward 
the  sutures  becoming  coarser  than  those  of  the  lateral  areas.  Poste- 
rior valve  depressed,  the  mucro  subterminal. 

Interior:  anterior  valve  having  about  9  slight  slits,  not  corre. 
spending  to  the  outside  dots.  Central  valves  with  1  slit ;  teeth 
striated  outside  and  at  the  broad,  but  sharp  edge.  Eaves  planed  off, 
scarcely  grooved.  Sinus  broad,  deep,  with  about  14  denticles. 

Girdle  stout,  with  shelly  spines,  exactly  like  magellanicus,  prin- 
cipally whitish,  irregularly  tessellated  with  dark.  (Cpr.,  from 
type.)  Length  18,  breadth  10  £,  divergence  90.° 

Nine  or  Savaye  Island,  Friendly  Group  (Brenchlev.) 

Chiton  ( Onithochiton)  amicorum  BAIRD,  in  Brenchley's  Jotting* 
during  the  Cruise  of  H.  M.  S.  'Curacoa'  among  the  South  Sea 
Islands,  in  1865.  London,  1873,  p.  445,  t.  40,  f.  7. 

The  generic  position  of  this  species  is  uncertain,  but  could  be 
readily  ascertained  by  an  examination  of  the  type,  which  is,  we 
believe,  in  the  British  Museum.  It  is  probably  either  an  Onithochiton^ 
a  Liolophura  or  a  Plaxiphora.  Baird's  original  description  is  as 
follows:  "Shell  ovate,  nearly  equal  at  each  extremity;  mantle 
margin  covered  with  numerous  chaffy-looking  scales,  first  valve 
larger  than  any  of  the  others,  marked  with  numerous  granular  lines  ; 
central  valves  strongly  striated,  lateral  areas  with  2  or  3  granular 
lines ;  last  valve  small  and  striated.  A  line  of  a  red  color  runs 
along  the  top  of  all  the  valves,  whilst  "one  or  two  others  run  along 
the  lateral  areas.  Length  8  lines,  breadth  5J  lines." 

O.  MAILLARDI  Deshaves.     PI.  55,  fig.  20. 

Shell  oblong,  elevated,  the  dorsal  ridge  roundly  angled,  side- 
slopes  nearly  straight.  Surface  shining  ;  color  pale  buff,  with  a  nar- 
row orange-tinted  or  brown  triangle  at  the  ridge  of  each  valve, 
several  dark -green  spots  along  each  diagonal  slope,  the  lateral  areas 
and  head  valve  with  concentric  green-olive  sometimes  dark  brown 
lines. 

Median  valve  beaked,  the  lateral  areas  somewhat  raised,  having 
near  the  front  margin  a  narrow  radiating  band  of  eye-dots,  the  width 
of  the  band  greater  on  the  hinder  valves;  sculptured  with  longitu- 
dinal grooves  corresponding  with  the  dark  color-lines,  sometimes 
irregular  or  branching;  and  continuing  upon  the  diagonal  slope. 
Upon  the  central  areas  these  grooves  become  much  more  delicate,. 


<>M  I  II...   in  I 


closer,  M>D  Vtfging  tOWftrd  tin-  dorsal  riil^r.  and  oftni  /igzagged  ;  the 
median  triangle  of  the  central  arras  >inooth.  A  ntrrior  valve  having 
8  narrow  rays  of  ryes,  i.rra-ionally  with  ,-onie  eye-  >eatt«  red  between 
along  the  lower  margin  ;  the  intervals  between  the  eye-rays  sculpt- 
ured with  sulei  forming  short  arcs  of  concentric  grooves.  Posterior 
valve  depressed,  triangular;  //••«  /on/tit  from  sinus  to  ///'•  //".iterior 
terminal  inncro  briny  one-  half  the  greatest  breadth  of  its  tegmentum. 

Interior  white,  with  a  large  spot  of  rich  brown  in  each  valve. 
Sinus  delicately  toothed,  wide  and  deep.  Anterior  valve  having  8 
slits,  median  valves  1  slit  ;  teeth  finely  and  sharply  pectinated  out- 
side. Posterior  valve  having  a  smooth  ledge  of  callus  in  plate  of 
the  insertion-plate,  flat  behind,  rounded  at  the  sides.  Eaves  narrow, 
grooved,  solid. 

Girdle  fleshy-brown,  leathery. 

Length  24,  breadth  15  mill.;  divergence  110°-115°. 

Mauritus  and  Bourbon  (Reunion.) 

Chiton  maillardi  DESH.,  Moll,  de  File  Reunion,  p.  38,  t.  5,  f.  14. 
—  Chiton  (Toniciaf)  maillardi  MARTENS,  in  Mobius'  Reise  nach 
Mauritius,  p.  300.  —  Ornithochiton  maillardi  CPR.,  MS.  —  Ornitho- 
chiton  sp.,  MOSELEY  Quarterl.  Journ.  R.  Mic.  Soc.  xxv,  p.  54,  t.  5, 
f.  4-7. 

O.  LITERATUS  Krauss.     PI.  55,  figs.  21,  22,  23. 

Shell  ovate,  convex  ;  brown,  spotted  with  whitish  and  having  a 
whitish  longitudinal  band  ;  closely  silicate.  Interior  white,  brown- 
ish-violet in  the  middle.  Anterior  valve  lunate,  convex  with 
undulating  grooves  ;  posterior  valve  triangular,  depressed,  sculptured 
with  angular  grooves;  intermediate  valves  sinuated  in  front, 
rounded  at  the  sides,  undulately  and  angularly  grooved.  Girdle 
rufous-brown,  leathery,  velvety. 

Length  12,  breadth  8  lines.     (Krauss.) 

Natal. 

Chiton  literatus  KRAUSS,  Die  Siidafrik.  Moll.  p.  36,  t.  3,  f.  6. 

I  have  not  seen  this  secies,  which  is  evidently  quite  distinct, 
although  allied  to  0.  maillardi.  The  central  areas  have  angular  or 
zigzag  grooves;  the  lateral  areas  are  not  raised,  and  are  sculptured 
with  wavy  grooves.  The  back  is  not  carinated.  Insertion  plates  as 
usual  in  the  genus. 


252  ENOPLOCHITON. 

Genus  XX.    ENOPLOCHITON  Gray,  1847. 

Enoplochiton  GRAY,  P.  Z.  S.  1847,  pp.  65,  69,  169. 

Valves  exposed,  of  a  uniform  dark  brown  or  chocolate  color  out- 
side and  within ;  the  lateral  areas  and  head  valve  irregularly 
studded  with  extremely  minute  eyes.  Interior  minutely  laminated 
and  punctate  in  a  peculiar  pattern  ;  sinus  deep,  denticulate.  Inser- 
tion-plates of  anterior  and  median  valves  slit  into  teeth  and  sharply 
pectinated  outside.  Tail-valve  having  the  mucro  posterior  and 
terminal,  and  inside  with  a  flat  ledge  of  callus  in  place  of  the  lack- 
ing insertion-plate.  Girdle  fleshy,  bearing  extremely  broad  and 
short,  blunt,  separated  striated  scales. 

The  single  species  comprised  in  Enoplochiton  resembles  the  larger 
Onit/iochitons  in  being  polished  and  sculptured  with  wavy  impressed 
lines  (when  not  eroded)  and  also  in  the  denticulate  sinus,  as  well  as 
in  the  structure  of  all  the  insertion-plates.  It  differs  from  Onitho- 
chiton  in  the  peculiar  texture  and  color  of  the  valves,  the  sculpture 
of  the  interior  and  the  structure  of  the  girdle. 

The  eyes  in  this  genus  are  extremely  minute  and  oval  instead  of 
round.  The  megalopores  and  micropores  are  arranged  in  vertical 
lines  (pi.  52,  figs.  27,  28).  The  valves  resemble  those  of  Mesotoinura 
in  most  respects,  excepting  the  tail  valve,  which  is  that  of  Onitho- 
chiion. 

E.  NIGER  Barnes.     PL  52,  figs.  22-29. 

Shell  oblong,  convex,  the  valves  thick  and  dark  brown  outside 
and  within.  Surface  shining  when  perfect,  but  generally  eroded 
and  dull. 

The  valves  are  strongly  beaked,  and  generally  much  eroded*;  but 
when  not  too  much  worn  the  sculpture  is  as  follows  :  lateral  areas 
marked  with  undulating  longitudinal  impressed  lines ;  central  areas 
having  a  series  of  short  impressions  in  front  of  each  diagonal  rib, 
and  an  impressed  V  on  the  ridge  of  each  valve  ;  anterior  valve  hav- 
ing concentric  wavy  grooves ;  posterior  valve  much  depressed,  with 
posterior  terminal  mucro  ;  sculptured  like  the  median  valves. 

Interior  seen  under  a  lens  to  be  sharply,  densely  laminate  in  front 
of  the  valve  callus,  punctate  on  the  sutural  plates  and  behind  the 
valve-callus  (fig.  25).  Sutural  and  insertion  plates  of  median 
vulves  thick,  tending  forward;  sinus  broad,  rounded  or  angular, 
denticulate;  anterior  valve  having  9  slits,  median  valves  1  slit; 
teeth  long,  deeply,  shaq^ly  and  closely  pectinated  outside.  Posterior 


ISCIIN'M    HI  I"M  I'   1  . 

valve  having  tin-  inticro  projecting  beyond  the  narrow  eaves;  inser- 
tion plate  obsolete,  reduced  to  a  callous  ridge,  flattened  behind, 
rounded  at  tin-  side.s  and  pectinated  outside  where  it  joins  the 
sutural  plates. 

Girdle  fleshy,  bearing  numerous  wide,  short,  blunt,  striated,  sepa- 
rated scales  (fig.  29,  a  young  specimen)  ;  the  interstices  between  the 
scales  covered  with  a  velvety  pile. 

Length  75-80,  breadth  35-40  mill. 

Peru  (Capt.  Ridgeley)  ;  Coquimbo  Bay  (Frembly)  ;  Valparaiso 
(U.  S.  Expl.  Exped.) 

Chiton  niger  BARNES,  Amer.  Journ.  of  Science  and  Arts,  vii,  p. 
71,  t.  3,  f.  3  (1824).— Enoplochiton  niger  GRAY,  P.  Z.  S.  1847,  p.  69. 
—  Chiton  coquimbensis  FREMB.,  Zool.  Journ.  iii,  p.  197,  t.  16,  f.  2 
(1827).— SOWERBY,  Voy.  'Blossom'  Zool.,  p.  149,  t.  40,  f.  6.— 
REEVE,  Conch.  Icon.,  f.  22. 

The  entire  substance  of  the  valves  is  colored  in  this  remarkable 
species.  Specimens  as  well  preserved  as  the  individual  figured  are 
not  common  ;  but  so  peculiar  is  the  entire  shell  that  it  may  readily 
be  recognized,  however  eroded. 

This  species  like  Acanthopleura  spinifera,  lives  upon  the  rocks 
between  tides  in  situations  exposed  to  the  full  force  of  the  surf.  In 
fig.  27  a  portion  of  the  surface  of  a  valve  is  drawn  magnified,  show- 
two  eyes,  megalsesthetes  and  micrsesthetes  ;  fig.  28  represents  a  por- 
tion more  highly  magnified,  showing  two  megalsesthetes  and  the 
accompanying  micrsesthetes. 

Family  ISCHNOCHITONID^. 

A  number  of  genera  belonging  to  the  Ischnochitonidce  were 
omitted  by  me  in  my  treatment  of  it  in  parts  1  and  2  of  this  volume, 
in  deference  to  the  views  of  Carpenter,  who  grouped  them  with 
Acanthopleura  and  its  allies.  A  more  profound  study  of  this  and 
related  families,  enables  me  now  to  see  traits  of  relationship  unknown 
at  the  time  the  synopsis  on  pages  23,  24,  25  was  prepared,  and  there- 
fore to  group  the  genera  more  naturally  than  was  then  possible. 

Subfamilies  of  Ischnochitonidce. 

CALLISTOPLACINJE,  in  which  the  slits  of  the  anterior  and  inter- 
mediate valves  correspond  in  position  to  radiating  ribs  on  the  exte- 
rior. (See  p.  259.) 


254 


I8CHNOCHITOMN  1  -DINOPLAX. 


i,  in  which  there  is  apparently  no  such  relation 
between  slits  and  external  ribs. 

This  last  subfamily  includes  the  majority  of  species,  and  a  consider- 
able number  of  genera ;  and  while  there  are  still  some  obscure  points, 
the  light  cast  by  what  we  already  know  of  their  morphology  is  suffi- 
cient to  show  us  the  approximate  paths  of  generic  descent,  the  genera 
falling  into  three  main  groups,  as  shown  in  the  diagram. 


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Ischnochitoninse 


Callistoplacinse 


It  will  be  noticed  that  Leptoplax  and  Spongiochiton  are  not 
included.  These  genera  belong  to  the  Acanthochitidaz.  Moreover,  it 
must  be  remembered  that  Trachyradsia  is  a  synonym  of  Stereochiton 
(see  p.  52)  and  part  of  Trachydermon  belongs  to  the  Tonicelloid 
branch.  These  groups  were  erroneously  placed  in  the  text. 

The  following  genera  belong  to  the  Chudopleuroid  branch  of 
Ischnochitoninae  and  should  have  been  inserted  after  the  genus 
Chcetopleura  (p.  27.) 

Genus  XXL     DINOPLAX  Carpenter,  1882. 

Dinoplax  CPR.  MS.,  in  DALL,  Proc  U.  S.  Nat.  Mus.  1881,  p.  284, 
287  (Jan.  20,  1882).— Acanthopleura  (in  part)  GRAY.—  Chwtopleura 
(part)  Sur  i  n. I:\VMR  MI.— r/,,7o»  s.  s.  (in  part)  ADAMS,  Gen.  Rec. 
Moll,  i,  p.  474,  475,  not  of  Linn. 

Valves  heavy,  exposed,  the  lateral  areas  high  ;  teeth  of  insertion 
sharp,  smooth,  those  of  the  posterior  valve  directed  forward;  slits  of 


anterior  \alvr  not  rorn^|.ondin_r  t<»   i-xtrrnsil    rilis.        Posterior 
luiriii'i  the  vnici".  }n>*teri'n-.      Suitttal plafat  fn-nml/i/  imitxl  across  the 
sinus.     <  iinllr  thick,  lent  licry,  with  minute  Imm'hes  of  delicate  sjnne- 
lets  scattered  upon  it. 

The  position  assigned  by  Shuttleworth  to  the  type  of  this  genus 
was  not.  tar  from  correct.  The  Ischnoid  insertion-plates, solid  eaves 
and  the  leathery  spiculose  girdle  are  characters  strongly  binding  C. 
<ji<i<i.<  to  ( '/nrfttjtlfura.  Upon  parting  the  valves,  however,  we  notice 
that  the  macro  in  C.  gigas  is  situated  toward  the  rear,  and  the  [in- 
terior teeth  are  thereby  thrown  forward,  as  in  Pallochiton ;  the 
sutural  plates  are  united  by  a  brown  "keystone"  filling  the  sinus 
somewhat  as  in  Endoxochiton  (p.  192)  ;  and  the  spicules  of  the  girdle 
are  gathered  into  little  bunches  different  from  any  other  Chiton. 
The  valves,  too,  are  remarkably  solid.  This  combination  of  char- 
acters seems  sufficient  for  the  establishment  of  the  genus  Dinoplax, 
the  position  of  which  I  take  to  be  near  Pallochiton. 

D.  GIGAS  Gmelin.     PI.  57,  figs.  21-32. 

Shell  oval,  large,  ponderous  and  strong,  elevated,  obtusely  angled. 
Surface  lusterless,  eroded,  ash-white  in  color  with  some  brown 
smears,  when  adult;  the  young  being  prettily  streaked  or  mottled 
with  chestnut  and  bluish  on  a  light  ground. 

Median  valves  not  beaked  ;  lateral  areas  very  much  elevated, 
radially  striated  in  young  shells  and  upon  the  outer  edges  of  adults  ; 
central  areas  closely  and  finely  foveolate  in  the  young,  and  on  the 
protected  front  edge  of  adult  valves.  Anterior  valve  elevated,  its 
surface  similar  to  the  lateral  areas.  Posterior  valve  depressed  but 
roof-shaped,  the  mucro  posterior,  the  slope  behind  it  nearly  vertical. 

Interior  whitish,  flesh-colored  on  the  sutural  plates  and  marked 
with  brown  at  their  bases;  having  two  broad  chestnut  rays  behind. 
Sutural  plates  wide,  connected  across  the  sinu*  by  a  broad  key-stone 
shaped  lamina.  Anterior  valve  having  8-10,  central  valves  1,  pos- 
terior valve  8-10  slits ;  teeth  acute,  smooth,  those  of  the  posterior 
valve  rather  stumpy,  wedge-shaped,  directed  forward.  Eaves  solid. 

Girdle  fleshy,  strong,  blackish,  beset  with  numerous  tiny  bunches 
of  minute  spinelets  (fig.  31.) 

Length  70,  breadth  45  mill. 

Length  100,  breadth  56  mill. 

South  Africa,  at  Table  Bay,  Natal,  Port  Elizabeth  and  Algoa  Bay. 

Chiton  tnaj-imu*  a  Promontorio  Bomc  Spei  CHKMNITZ,  Von  einem 
Geschlechte  vielschalichter  Conchylien  mit  sichtbaren  Geleuken, 


256  PALLOCHITnN. 

fig.  10  (1784). —  Chiton  maximus  *eu  pipof  CHSHHITZ,  Com-hyl.  Cab. 
viii,  p.  292,  t.  96,  f.  819  (good),  1 785.—  Chiton  gigas  GMEL.,  Syst. 
Nat.  xiii,  p.  3206  (1788).— SPENGLER,  Skrivter  af  Naturhistorie- 
Selskabet,  iv,  p.  101  (1795).— WOOD,  Gen.  Conchol.,  p.  12  (1814). 
— BRUG.,  Encyclop.  Meth.,  t.  161,  f .  3  (copied  from  Chemnitz). — 
LAMARCK,  An.  s.  Vert,  vii,  p.  490. — BLAINVILLE,  Diet.  Sc.  Nat. 
xxxvi,  p.  543. — REEVE,  Conch.  Icon.,  f.  65. — KRAUSS,  Die  Siidafrik. 
Moll.,  p.  40,  t.  3,  f.  3  (young).— H.  &  A.  ADAMS,  Genera  Rec.  Moll, 
p.  475. — SOWB.,  Marine  Sh.  of  South  Africa,  p.  50. —  Chalopleura 
gigas  SHUTTLEW.,  Bern.  Mittheil.  1853,  p.  67. — Acanthopleura  gigas 
GRAY,  P.  Z.  S.  1847,  pp.  68,  169.— Chiton  siibgigas  BLAINVILLE, 
Diet.  Sc.  Nat.  p.  543  (young  specimen). — Dinop lax  gigas  CrR.,  MS. — 
Chiton  albus  BARBUT,  The  Genera  Vermium  of  Linnseus,  Pt.  2d. 
(London,  Mar.  2,  1788),  Vermes  Testacea,  p.  8,  t.  1,  f.  1  (not  Ch. 
albus  Linn.) 

The  dull,  corroded  aspect  of  this  large  species  seems  to  be  invari- 
able in  adults.  The  strongly  raised  lateral  areas,  black,  leathery 
girdle,  and  peculiar  contour  render  it  very  distinct  in  appearance. 
The  figures  of  Chemnitz  are  most  characteristic,  but  that  it  is  impos- 
sible to  quote  him  as  authority  for  the  name  must  be  admitted. 
Although  the  bibliography  of  this  species  is  rather  extensive,  the 
only  references  worth  reading  are  Chemnitz,  Krauss  and  Carpenter. 

Rochebrune  has  cited  this  species  from  the  strait  of  Santiago,  Cape 
Verde  Archipelago  (Nouv.  Arch,  du  Mus.  iv,  p.  239,  1881),  but  his 
paper  contains  such  a  host  of  erroneous  locality  citations  that  one 
hesitates  to  accept  any  of  them  without  confirmation. 

Genus  XXII.    PALLOCHITON  Dall,  1882. 

Hemphillia  CARPENTER  JfSS.,  type  H.  lanuginosa  Cpr.  ^fSS. 
Not  Hemphillia  Bland  &  Binney. — Pallochiton  DALL,  Proc.  U.  S. 
Nat.  Mus.  1878,  p.  297  (dentition  described,  but  no  generic  diagnosis, 
and  founded  on  the  undescribed  species  P.  lanuginosiis.  Feb.  13, 
1879).— Pallochiton  DALL,  Proc.  U.  S.  Nat.  Mus.  1881,  p.  283,  287 
(Jan.  20,  1882).—?  Arthuria  CPR. 

Valves  exposed,  solid,  the  anterior  and  median  having  sharp 
insertion  teeth  slightly  roughened  outside ;  slits  of  anterior  valve 
not  corresponding  to  anything  in  the  external  sculpture  ;  tail  valve 
having  the  mucro  at  the  posterior  end,  the  teeth  sharp  and  all 
strongly  directed  forward  ;  eaves  solid ;  sinus  notched  at  sides. 
Girdle  leathery,  with  a  few  deciduous  hairs,  but  no  pores. 


PAI.I  CM  IN  i'  257 

This  J^MIIIS  rln-rly  rrsrinldrs  in  sculpture  a-  well  as  st ruct ural 
characters,  ('/nrtoj>/t'nr<t  Shuttlow.;  dilli-nuL:  only  in  tin-  posh-rior 
position  of  the  macro  and  the  consequent  throwing  forward  of  tin-, 
tail-valve  insert  ion-tec!  li, — characters  of  no  great  importance.  Th«- 
slits  correspond  in  position  to  nothing  in  the  external  sculpture. 
The  girdle  is  decidedly  like  Chcetopleura,  ln-in«r  vn-y  sparsely  hairy 
(or  smooth)  and  lacking  all  appearance  of  pores. 

P.  LANUGINOSUS  Carpenter,  n.  sp.     PL  56,  figs.  1-11. 

Shell  oblong  or  ovate,  rather  elevated,  carinated,  the  side-slopes 
nearly  straight.  Surface  lusterless,  color  very  variable  ;  sometimes 
dull  brown  or  purplish-brown  ;  sometimes  green  along  the  ridge  and 
purple  or  lilac  dotted  with  black  or  olive  at  the  sides  ;  or  having  the 
sides  of  some  valves  scarlet  or  even  snow-white. 

The  median  valves  are  rather  acutely  beaked  in  the  young,  beaks 
eroded  in  olcl  specimens.  Lateral  areas  but  little  raised,  sculptured 
with  gem-like  pustules  scattered  irregularly  on  a  flat  (microscopic- 
ally puncticulate)  ground  ;  the  pustules  often  few,  rarely  wanting 
on  some  valves ;  central  areas  sculptured  with  many  closely  beaded 
longitudinal  threads,  which  converge  slightly  at  the  ridge,  and 
diverge  toward  the  outer  sides  of  the  valves ;  on  the  second  valve 
they  diverge  at  the  ridge.  Head  valve  pustulose  like  the  lateral 
areas.  Tail  valve  (fig.  11)  much  depressed,  the  mucro  at  the  posterior 
end ;  anterior  area  wide,  sculptured  like  the  central  areas  ;  posterior 
area  very  narroiv,  vertical,  sometimes  pustulose. 

Interior  bluish-white,  darker  at  jugum  and  posteriorly  ;  rarely 
flesh  or  pink  tinted.  Sutural  plates  very  broad;  sinus  narrow, 
deep,  angular  and  notched  at  the  sides.  Anterior  valve  having  8-9, 
central  1  slit,  the  teeth  long,  sharp,  a  little  rugose  outside  ;  posterior 
valve  having  10-11  slits,  the  teeth  chisel- shaped,  strongly  directed 
forward,  smooth  and  rather  sharp.  Eaves  of  anterior  and  median 
valves  narrow,  of  posterior  valve  wider,  solid. 

Girdle  rather  fleshy,  leathery  when  dried,  somewhat  encroaching 
at  the  sutures,  and  smooth  or  clothed  with  sparse  delicate  hairlets. 

San  Diego,  California ;  Todos  Santos  Bay  to  Pta.  Abreojos,  Lower 
Cal. 

Hemphillia  lanuginosa  CPR.,  MS. — Pallochiton  lamtfjinofiiis  Cpr-. 
BALL,  Proc.  U.  S.  Nat.  Mus.  1878,  p.  297,  pi.  3,  fig.  21  (dentition). 
—  Chiton  (Pallochiton)  Imimjinosa  (Cpr.)  Dall,  ORCUTT,  Proc.  U.  S. 
Nat.  Mus.  1885,  p.  544. 
17 


258  PALLOCHITON. 

??  Chiton  pwuticukstui  REEVE,  Conch.  Icon.,  Chiton,  no.  69  (in 
part.) 

The  posterior  terminal  mucro,  leathery  girdle,  and  beaded  sculpt- 
ure well  distinguish  this  species.  The  coloring  of  some  specimens 
(such  as  those  from  S.  Ignacio  Lagoon,  Lower  California,  represented 
by  fig.  1,  6)  is  of  exquisite  delicacy.  Old  individuals  generally  lose 
the  pustules  of  the  surface  except  at  the  base  of  the  valves.  One  of 
Reeve's  illustrations  (fig.  69a)  is  said  to  represent  a  specimen  of  this 
species  ;  but  as  the  other  (fig.  696)  is  certainly  an  Onithochiton,  and 
as  the  description  indicates  that  rather  than  the  Pallochiton,  I 
have  preferred  to  retain  Carpenter's  name  for  this  species. 

A  peculiarity  of  coloring  not  mentioned  in  the  description  is  the 
vertical  white  stripe  extending  down  the  posterior  slope  from  the 
mucro  of  the  tail  valve.  In  the  great  number  of  individuals 
examined  by  me  I  have  never  found  this  lacking. 

Section  ARTHURIA  Carpenter,  1882. 

Arthitria  CPR.  MS.,  in  BALL,  Proc.  U.  S.  Nat.  Mus.  1881,  pp. 
284,  287  (Jan.  20,  1882).  Type  A.filosa  Cpr. 

Shell  thin  ;  valves  waved  ;  mucro  posterior,  produced.  Insertion 
plates  acute,  smooth,  projecting  forward  in  the  posterior  valve ; 
sinus  flat,  laminate,  smooth.  Girdle  leathery,  smooth  or  downy. 
(Cpr.,  MS.) 

This  section  seems  to  present  no  characters  separating  it  from 
Pallochiton.  I  have  not  seen  the  type  and  only  species,  and  it  has 
not  been  figured.  Comparisons  should  be  made  with  Pallochifon 
lanuginosus  Cpr. 

P.  i  ILOSUS  Carpenter,  n.  sp. 

Shell  oval,  subelevated,  the  dorsal  ridge  acute;  mucro  posterior, 
hardly  terminal,  elevated  on  a  strong  marginal  ridge,  the  outline  in 
front  of  it  concave.  Intense  or  pale  olivaceous. 

Valves  delicate,  rounded  at  the  margin,  making  deep  sutures. 
Central  areas  haiing  about  13  distant,  beaded  subparallel  threads  on 
each  side,  sometimes  obsolete,  and  closer  and  subacute  upon  the  ridge. 
Lateral  areas  moderately  defined,  and  together  with  the  end  valves 
having  irregularly  scattered  rounded  granules. 

Interior:  anterior  valve  having  10,  central  1,  posterior  valve  9- 

10  slits ;  teeth  of  the  posterior  valve  solid,  acute  at  the  edge,  strongly 

ned  forward,  the  slits  sloping;  the  other  valves  having  very 


acute  teeth.  Kaves  of  p..>trrii>r  valve  wide,  flat,  sul»pongy;  of 
other  valves  moderate,  hardly  Lrn>oved.  Sinus  narrow,  dccj.,  hardly 
toothed,  slit  at  the  sides,  at  t he  jmiet ion  of  the  sutural  plates. 

Girdle  leathery,  smooth  or  most  minutely  and  closely  downy. 

Length  '2\l  hreadth  16*  mill;  divergence  110°-120°. 

Habitat  unknown. 

Arthur  in filosa  CPR.  MS.  and  in  DALL,  Proc.  U.  S.  Nat.  Mus.  1881, 
p.  287  (name  only).  Types  in  Mus.  Cuming,  nos.  23,  38. 

Carpenter's  description  is  given  above.     He  remarks : 

"  This  shell  has  the  tail  plate  of  Nuttallina,  but  the  other  valves 
more  resemble  Chcetopleura  or  Tonicella.  It  is  known  externally  from 
Nuttaffina  by  the  nearly  smooth  girdle ;  but  would  hardly  be  distin- 
guished from  Omithochiton  except  by  the  regular  articulation  of  the 
insertion-plates.  In  the  Ischnoid  genera,  the  posterior  profile  from 
the  mucro  is  often  concave ;  in  this  the  anterior.  In  consequence  of 
the  great  projection  of  the  beak,  both  in  Nuttallina  and  Arthuria, 
the  posterior  teeth  appear  plumulate  rather  than  fissured  ;  a  char- 
acter also  seen  in  Callistochiton.  The  terminal  valve  in  both  the 
specimens  examined  are  exactly  alike  in  color  as  well  as  markings ; 
but  the  central  valves  in  one  specimen  are  of  a  much  lighter  color, 
with  more  delicate  and  well  developed  sculpture." 


Subfamily  CALLISTOPLACIN^E. 

Ischnochitonida3  in  which  the  slits  of  the  anterior  valve  correspond 
in  number  and  position  to  the  radial  ribs  of  the  exterior.  Teeth 
generally  thickened  at  the  edges  of  the  slits. 

In  this  subfamily,  which  seems  to  be  a  natural  division,  may  be 
placed  a  number  of  genera  widely  scattered  in  Carpenter's  scheme. 
These  genera  fall  into  three  groups,  or  branches,  lettered  a,  aa,  and 
aaa  in  the  following  table.  The  first  of  them  seems  to  have  affinities 
with  the  typical  Ischnochitons,  the  second  slightly  resembles  the 
Acanthochitidve,  and  the  third  may  be  somewhat  allied  to  the 
Mopaliidce. 

The  number  of  anterior  slits  sometimes  exceeds  the  number  of 
external  ribs,  so  that  the  subfamily  diagnosis  must  not  be  taken  too 
literally.  The  plan  of  structure  is  sufficiently  obvious;  but 
exuberant  Nature  knows  nothing  of  absolute  adherence  to  rules. 


260  CALLISTOCHITON. 

K<  y  to  genera  of  Callistoplacince. 

a.  Surface  of  valves  having  strong  radial  ribs ;  girdle  densely 

clothed  with  imbricating  scales,  CALLISTOCHITON. 

aa.  Surface  of  valves  granulated  or  pebbly  ;  girdle  not  densely 

imbricated  with  scales. 

b.  Anterior  valve  with  more  than  7  slits ;  sinus  very  spongy ; 

imicro  posterior,  NUTTALLINA. 

bb.  Anterior  valve  with  5  slits;  mucro  subcentral,  not  posterior, 

CRASPEDOCHITON.  ANGASIA. 
aaa.  Surface  of  valves  wrinkled  or  ribbed  ;  girdle  naked  except  for 

hairs  or  corneous  spines. 

b.  Valves  having  very  strong  radial  ribs;  girdle  naked,  with 

sutural  tufts,  CALLISTOPLAX. 

bb.  Valves   not   very   strongly  sculptured  ;  girdle   tough,    with 

corneous  curved  spine-like  processes,  CERATOZONA. 


Genus  XXIII.    CALLISTOCHITON  Carpenter,  1882. 

Callistochiton  CPR.,  Table  of  Regular  Chitons,  1873.— DALL,  Proc, 
U.  S.  Nat.  Mus.  1881,  p.  283,  289,  290  (Jan.-Feb.,  1882).—  Callo- 
chiton  (in  part)  H.  &  A.  Adams,  and  of  CARPENTER,  P.  Z.  S.  1865, 
p.  276,  not  of  Gray. 

Valves  conspicuously  sculptured ;  the  insertion-plates  short, 
smooth  or  nearly  so,  festooned,  being  curved  outward  at  the  ribs 
and  slit  there,  thickened  outside  at  the  edges  of  the  slits,  the  latter 
corresponding  in  position  to  the  ribs  of  the  outer  surface.  Sinua 
squared.  Mucro  median  or  post  median,  generally  depressed. 
Girdle  poreless,  densely  clothed  with  minute  striated  or  smooth 
scales.  Type,  Chiton  pukhellw  Gray. 

This  genus  differs  from  Ischnochiton  in  the  peculiar  insertion-teeth, 
which  are  curved  into  the  ribs  as  if  festooned,  in  the  relation  of  the 
slits  to  the  external  ribs,  and  in  the  tail  valve,  which  is  often 
peculiarly  humped. 

The  species  though  not  numerous,  are  widely  distributed,  Aus- 
tralia, Red  Sea,  Japan  and  the  Gulf  of  Mexico  together  furnishing 
about  half,  the  rest  being  from  the  western  coast  of  the  Americas, 
from  southern  California  to  northern  Chili. 

Nearly  all  of  the  species  have  the  lateral  areas  strongly  bicostate 
and  granose;  the  end  valves  have  strong  ribs,  the  number  of  which 


«  \  i.i  .1-1  n(  inioN.  261 

is  le-<  valuable  :is  :i  specific  cli;ir:ictcr  than  one  would  at  first  suppose, 
on  account  of  their  tendency  to  increase  by  splitting.  When  a  rib 
splits,  an  additional  slit  appears  in  the  insertion-plate;  so  that  this 
character  also  is  lamely  vitiated. 

The  best  characters  for  distinguishing  species  are  the  sculpture  of 
the  median  portion  of  the  central  areas,  and  the  contour  of  the  tail 
valve  ;  the  profile  of  the  latter  being  especially  characteristic  and 
constant. 

The  following  notes  from  Carpenter's  MS.  apply  more  especially 
to  the  more  typical  forms  :  "  It  is  quite  possible  that  in  their  earlier 
stages  these  curious  shells  resemble  Ischnochiton ;  but  as  they  pro- 
ceed toward  maturity,  while  they  spread  naturally  in  the  seven  ante- 
rior valves,  the  posterior  is  simply  raised  a  tier  higher ;  consequently, 
in  the  adult,  the  posterior  part  of  the  tail  plate  resembles  a  closed 
fist  outside;  and  within  the  teeth  and  eaves  are  very  broad  and 
blunt.  There  is  an  approach  toward  the  throwing  forward  observed 
in  Acanthopleura.  In  Ischnochiton,  whatever  be  the  external  sculpt- 
ure, the  row  of  teeth  follow  the  same  oval  line,  and  the  incisions  do 
not  correspond  (except  by  accident)  with  the  external  ribs ;  whereas 
in  Callistochiton  the  tooth  line  is  elegantly  scalloped  in  and  out 
of  the  hollows  of  the  ribs. 

"  In  general  the  incisions  are  in  the  centre  of  each  rib,  and  the 
plates  are  there  propped  outside,  as  in  Callochiton ;  but  sometimes  a 
separate  keystone  (as  it  were)  is  let  into  some  or  all  of  the  arches  on 
the  terminal  valves.  The  genus  appears  to  culminate  on  the  Cali- 
fornia coast,  and  reaches  its  greatest  development  in  C.  palmulatus  ; 
in  which  the  posterior  valve  displays  the  further  peculiarity  of  each 
tooth  being  broken  up  into  a  number  of  fingers,  each  fluted,  and  so 
arranged  that  the  inner  margins  form  a  semicircle  while  the  outer 
present  the  scalloped  curve  of  the  genus.  The  valves  are  peculiarly 
solid  and  are  easily  detached  from  the  thin  and  narrow  zone.  The 
sinus  has  always  a  lamina,  which  is  generally  marked  off  by  slits  from 
the  sutural  lamina,  but  is  scarcely  ever  dentate.  Two  of  the  species 
have  minute,  smooth  scales." 

Key  to  species  of  Callistochiton. 

One  species,  C.  heterodon  Pils.,  has  pectinated  teeth  like  a  typical 
Chiton,  and  it  is  placed  in  this  genus  with  much  doubt ;  the  others 
may  be  tabulated  thus : 


262  CALLISTOCHITON. 

a.  Central  areas  having  a  pitted  or  net-like  pattern  toward  the 
beaks. 

b.  Mucro  posterior,  not  depressed,  tail  valve  with  7  ribs; 

scales  smooth,  pulchellu*. 

bb.  Mucro  subcentfal,  the  slope  behind  it  concave,  scales 

striated,  shuttleivort/i  Inn  n*. 

bbb.  Mucro  subcentral,  tail  valve  rapidly  sloping  backward 

from  the  front  margin ;  eaves  narrow ;  scales  striated, 

(inilquus. 

aa.  Central  areas  smooth  in  the  middle,  decoratus. 

aaa.  Central  areas  sculptured  throughout  with  parallel  lira. 

b.  Posterior  area  of  tail  valve  swollen  above  the  anterior 
area,  palmulatus. 

bb.  Posterior  area  not  higher. 

c.  Mucro  posterior  ;  riblets  converging  on  ridge, 

crassicostaius. 

cc.  Mucro  subcentral,  riblets  not  converging  on  ridge. 
d.  Profile  of  tail  valve  convex,  mucro  obtuse, 

infortunatus. 

dd.  Profile  of  tail  valve  rapidly  sloping  'back- 
ward from  the  front  margin,  mucro  flat, 

gabbi. 

The  species  elenensis  and  expressus  from  western  Middle  Amer- 
ica, and  adenensis  from  the  Red  Sea,  probably  belong  in  the  last 
section  of  the  above  table,  but  I  have  seen  no  specimens.  C.jacob- 
&U8  of  Gould  also  belongs  near  infortunatus,  probably. 


C.  PALMULATUS  Carpenter,  n.  sp.     PI.  58,  figs.  7-16. 

Shell  similar  to  C.  pulchellus,  but  more  flattened,  the  dorsal  ridge 
acute;  mucro  subcentral,  depressed,  the  posterior  area  strongly 
swollen;  sculpture  stronger;  central  areas  having  about  10  sub- 
parallel  acute  line  on  each  side,  pectinatiug  the  sutures,  interstices 
deeply  cancellated;  lateral  areas  having  two  strong  ribs  bearing 
strong  tubercles,  the  sutures  dentate,  interstices  deeply  punctate. 
Anterior  valve  having  11  ril>>,  of  which  the  outer  two  are  joined; 
posterior  valve  7  very  strong  ribs  bifurcating  behind. 

Interior:  anterior  valve  having  11  slits,  central  1  slit,  the  teeth 
normal ;  posterior  valve  having  26  slits,  the  teeth  crowded,  minute, 
palmate.  Eaves  very  strong;  sinus  small,  strongly  laminate,  the 


•   M.i.isTorm  i'  W, 

lamina  di-eply  slit  on  each  side,  (iirdlc  imbricated  with  striated 
scales. 

Lcnirth  1  1  !,  hrradth  7-1  mill.;  divergence  l-'if)0.     (Cpr.) 

N/rf.  n.irbnra  (Cooper,  Cal.  State  Coll.  no.  1077)  ;  Monterey  (Can- 
field,  coll.  Cpr.) 

The  above  description  is  quoted  from  Carpenter's  MS.  He  gives 
the  following  additional  notes:  "  This  species  with  a  general  resem- 
blance to  pulchcllns,  is  known  outside  by  its  stronger  sculpture,  flat- 
tend  anterior  and  tumid  posterior  valve  ;  and  by  its  sharp  back  with 
flattened  sides.  It  is  one  of  the  most  remarkable  peculiarities  of 
Chitons  that  they  are  so  particular  in  special  adornment  of  their  tails, 
while  their  heads  are  covered  with  very  uniform  plates.  In  this 
species  this  peculiarity  culminates.  Not  only  the  radiating  and  fur- 
belowed  arrangement  of  the  teeth  presents  the  greatest  differentiation 
yet  observed  in  a  Chiton,  but  the  fluting  of  each  individual  finger- 
like  tooth  adds  special  beauty  to  the  complex  pattern." 

Figures  7,  8, 13-16  are  from  drawings  prepared  for  Dr.  Carpenter ; 
fig.  12  represents  the  tail  valve  of  a  typical  specimen  before  me,  for 
comparison  with  that  of  the  following  variety. 

Var.  MIRABILIS  Pilsbry,  n.  v.     PI.  58,  figs.  7,  8,  9,  10,  11. 

Shell  oblong,  elevated,  the  back  angular,  side-slopes  convex. 
Surface  lusterless,  dull  brownish,  the  lateral  areas  and  end  valves 
blackish. 

Valves  not  beaked;  the  lateral  areas  widely  separated  by  the 
eroded  beaks,  greatly  elevated,  each  split  by  a  deep  median  sulcus,  the 
two  ribs  thus  formed  bearing  coarse  transverse  grains.  Central  areas 
sculptured  with  about  15  narrow  longitudinal  cords,  parallel  at  the 
dorsal  ridge  except  on  the  second  valve  in  which  they  diverge  forward ; 
the  interstices  wider  than  the  cords,  and  finely  latticed  across. 
Anterior  valve  having  9  stout  radiating  ribs,  strongly  granose,  and 
with  the  exception  of  the  two  outer  ones,  they  are  generally  not  bifid. 
Posterior  valve  much  higher  than  the  anterior,  the  mucro  somewhat  in 
front  of  the  middle,  the  area  behind  it  enormously  developed,  >  I  r<if,,( 
and  convex,  sculptured  with  4,  5  or  6  primary  stout  ribs,  each  of 
which  splits  into  two ;  the  two  outer  ribs  are  broader,  and  split  into 
several  riblets. 

Interior  bluish-white;  sutural-lamime  slightly  connected  across 
the  squarish  sinus.  Anterior  valve  having  9,  central  1,  posterior 
valve  22  slits ;  teeth  short,  somewhat  roughened.  Eaves  broad, 
calloused. 


264  .        CALLISTOCHITON. 

Girdle  narrow,  thin,  covered  with  very  densely  imbricating 
minute  deeply  striated  scales  (fig.  8.) 

Length  16,  breadth  7  mill. 

San  Diego,  California. 

The  form  described  above  was  known  to  Dr.  Carpenter  by  one 
perfect  though  worn  specimen  and  a  single  worn  posterior  valve. 
He  gives  (MSS.,  p.  134)  the  following  notice  of  it,  under  C.  palm- 
iilutus. 

"?  Variat. :  ar.  centr.  liris  utr.  lat.  16-18;  v.  post.  5,  bifurcatis; 
mucro  usque  ad  dimidium  totius  altitudinis  depresso ;  sinus  lamina 
vixfissata.  Long.  15,  lat.  7*,  diverg.  110°." 

These  lines  give  the  essential  points  of  difference  between  this 
variety  and  the  typical  form,  viz.,  the  more  numerous  side  riblets  of 
the  central  areas  in  a  shell  of  the  same  width,  the  greatly  elevated 
posterior  area  of  the  tail  valve,  the  greater  proportionate  length  and 
altitude  of  the  shell  and  the  smaller  angle  of  divergence.  The  value 
of  these  characters  for  distinguishing  the  two  forms  remains  to  be 
seen,  and  can  only  be  ascertained  by  the  examination  of  abundant 
material.  That  this  form  is  not  merely  a  fully  grown  (ephebic)  or 
old  (geroutic)  state  of  the  original  palmulatus  is  shown  by  the  com- 
parison of  small  specimens,  not  exceeding  in  length  the  typicalpafa- 
11  lat  us  before  me. 

The  enormously  swollen  posterior  area  of  the  tail  valve  separates 
this  from  all  other  species.  In  several  additional  details  the  form 
differs  from  C.  crassicostatus,  notably  in  the  strongly  two-ribbed 
lateral  areas,  the  more  numerous  ribs  of  the  anterior  valve,  the 
riblets  of  the  central  areas  being  parallel  at  the  ridge  except  on  the 
second  valve  where  they  diverge ;  whilst  in  C.  crassicostatus  they 
converge  forwardly  on  all  of  the  median  valves.  The  seventh 
valve  of  this  form  is  distinctly  narrower  than  the  other  valves,  being 
crowded  by  the  unusually  developed  tail-valve. 

The  type  specimen  is  in  the  collection  of  the  Academy. 

C.  CRAS3ICOSTATUS  Pilsbry,  n.  sp.     PI.  58,  figs.  1,  2,  3,  4,  5,  6. 

Shell  oblong,  elevated,  the  dorsal  ridge  very  obsoletely  angular, 
side-slopes  arched.  Surface  lusterless,  green  or  brown. 

Valves  not  beaked,  the  lateral  areas  extremely  in-ominent.  mien  ///// 
granu/'it*  /,  the  concentric  riblets  being  cut  by  one  or  several  radiat- 
ing grooves.  Central  areas  having  strong  longitudinal  bars,  con- 
verging \-like  on  the  indge  (even  on  the  second  valve],  the  intervals 


CA  l.USTi  H   II II'  >\  . 


\ery  oloeelj  and  finely  latticed  across.     Anterior  v<t/w  Ham 
very  stro in/  ril>.<,  cadi  divided  by  a  shallow  median  gTOOY6.       I'oste- 
rior  valve  elevated,  having  ///'  macro  directly  over  the  }>  '/.'/', 

//'  hinder  ttrcn  not  h'njln-r  than  the  arco  in  front  of  it;  posterior 
slope  vertical,  convex,  sculptured  with  live  very  strong,  deeply 
separated  ribs,  which  are  i^rauose  above,  and  subdivide  into  several 
riblets  each  toward  the  lower  margin. 

Interior  bluish-white  ;  sutural-plates  slightly  connected  across  the 
rounded  sinus.  Anterior  valve  having  9,  central  valves  1,  poste- 
rior valve  13-20  slits ;  teeth  short,  rather  sharp  and  smooth,  hardly 
projecting  below  the  eaves,  thickened  along  the  slits  outside ;  eaves 
broad,  solid. 

Girdle  narrow,  thin,  covered  with  excessively  minute,  closely 
imbricating,  striated  scales. 

Length  22,  breadth  9  mill. 

Monterey,  California. 

Callixtochiton  fimbriatus  CPR.,  MSS.  1875.  Not  Callochiton  fim- 
briatus  Cpr.  in  COOPER,  Geographical  Catalogue  of  the  Mollusca 
found  west  of  the  Rocky  Mountains,  between  Latitudes  33°  and  49° 
North  (Geol.  Surv.  of  Cal.),  p.  23,  1867  (no  description),^  Callisto- 
chiton  pulchellus,  Cpr.  MSS.  1875. 

?  Chiton  (  Callochiton}  fimbriatus  Cpr.,  ORCUTT,  Proc.  U.  S.  Nat. 
Mus.  1885,  p.  544  (1885),  no  description.  Not  Chiton  fimbriatus 
SOWB. 

This  species  is  readily  separated  from  the  next  by  the  smaller 
number  of  ribs  on  the  head  and  tail  valves,  the  less  distinctly  bicos- 
tate  lateral  areas,  and  the  far  less  elevated  tail  valve,  which  has, 
besides,  a  posterior  terminal  mucro. 

The  specimens  before  me  were  collected  by  Henry  Hemphill  at 
Monterey.  A  species  under  this  name  has  been  reported  from  San 
Diego  and  from  Catalina  Island,  but  the  identity  of  the  specimens 
with  the  present  species  is  open  to  doubt,  although  its  occurrence  in 
those  places  is  not  improbable. 

The  name  of  this  species  is  involved  in  some  obscurity,  owing  to 
the  fact  that  no  diagnosis  or  description  whatever  has  heretofore  been 
published,  although  the  name  fimhrintns  has  appeared  in  several 
lists.  This  much  however  is  certain:  that  the  original  fimhrintn* 
Cpr.  of  Cooper's  Catalogue,  the  unique  type  of  which  is  said  to  be  in 
the  Smithsonian  Institution  collection,  is  not  the  fimbrixfus  of  Car- 
penter's later  MSS.  (  Vi>1>-  <  'arpenter's  MSS.  vol.  I,  p.  135)  ;  and  we 


266  CALLISTOCHITON. 

have  no  means  of  knowing  whether  the  C.  fimbriatus  of  Orcutt's  San- 
Diego  list  was  identified  from  Carpenter's  earlier  type  specimen,  or 
his  later  MSS.  Everything  considered,  the  best  course  open  to  us 
seems  to  be  the  selection  of  an  entirely  new  name.  The  type  is  in 
the  collection  of  the  Academy. 

C.  INFORTUNATUS  Pilsbry,  n.  sp.     PI.  59,  figs.  37-42. 

Shell  large,  regularly  ovate,  the  dorsal  ridge  obtuse ;  valves 
arcuate ;  mucro  obtuse,  median.  Olivaceous,  sometimes  spotted  with 
paler  on  the  ribs  and  jugum. 

Central  areas  having  about  12  parallel  lirse  on  each  side,  decussated, 
the  interstices  having  square  depressions.  Lateral  areas  having  two 
very  strong  rounded  tuberculose  ribs.  Anterior  valve  with  9,  pos- 
terior with  7-8  elegantly  spreading  ribs. 

Interior:  posterior  valve  having  7-8,  central  1,  anterior  9  slits ; 
teeth  concave  outwardly,  obtuse,  slit  at  the  apices  of  the  ribs,  some- 
times with  an  intercalated  slit  or  abnormally  serrate ;  teeth  of  poste- 
rior valve  very  obtuse,  hardly  sloping  ;  eaves  small,  delicate.  Sinus 
wide,  flat,  but  little  angular,  sometimes  crenulated  by  the  riblets  of 
the  exterior.  Girdle  irregularly  imbricated  with  flattened  scales, 
each  one  about  6-striated  (fig.  39.) 

Length  17*,  breadth  8|  mill. 

Equador  (Cuming)  ;  La  Paz,  W.  Mexico  (Pease.) 

Callistochiton  pulchellus  CARPENTER,  MSS.  Not  C.  pulchellus 
Gray,  q.  v. 

The  sculpture  of  the  central  and  lateral  areas  resembles  that  of  C. 
palmulatus,  but  the  tail-valve  (figs.  38, 42)  is  entirely  different  in  form. 
This  shell  was  sent  to  Dr.  Carpenter  by  Cuming  as  the  true  C. 
pulchellus  of  Gray,  but  it  is  certainly  not  that  species.  The  above 
description  and  the  figures  are  from  Carpenter's  MSS.  and  unpub- 
lished drawings  of  his  type. 

The  shell  recorded  by  Dr.  J.  G.  Cooper  from  "  Catalina  (or  other?) 
I.,  Cal."  under  the  name  Callocliitmt  ihnbrintus  Cpr.  MSS.,  and  by 
Carpenter  (in  MSS.)  from  "  S.  Pedro  "  (both  referring  to  the  same 
specimen)  may  be  a  variety  of  this  species,  but  no  definition  of  it 
has  been  published,  the  locality  is  uncertain,  and  Dr.  Carpenter  in  his 
later  MSS.  shifted  the  n&m6  fimbriatut  to  another  species,  leaving  the 
form  under  discussion  as  a  nameless  variety  of  his  C.  pulchellus. 
Under  these  circumstances  it  has  been  thought  best  to  expunge  the 
name  fimbriatiui  from  the  list  of  valid  species. 


OALUVfOCHITOV,  -'•" 

C.  JAC«»i;  r.l  s  (Jould.        f'ntiiflli'cd. 

Shell  small,  ashy,  elongated,  elliptical,  hardly  carinate.l  ;  end 
valves  very  lar^-,  vaulted,  ornamented  with  10  scaly  nuliatinir  ril>> ; 
central  areas  cancellated;  lateral  areas  conspicuous,  bicostate. 
Ligament  narrow,  covered  with  minute  elongated  scales. 

Length  12,  breadth  5  mill.     (UM. ) 

Interior:  posterior  valve  having  7,  anterior  10,  central  1  slit; 
teeth  acute,  curved  outwardly  ;  eaves  solid  ;  sinus  wide,  nearly  flat, 
laminate,  the  lamina  more  or  less  separated  from  the  sutural  plates 
[by  notches  at  the  sides  of  the  sinus].  Girdle  imbricated  with  flat, 

striated  scales.     (  Q>r.) 

Simoda,  Japan  (North  Pacific  Expl.  Exped.) 

C.  (Leptochiton)  Jacobceus  GLD.,  Proc.  Boston  Soc.  Nat.  Hist,  vii, 
p.  164  (Dec.,  1859)  ;  Otia  Conch.,  p.  117. —  Caltistochiton  jacobceus 
CPR.,  MSS. 

Carpenter  gives  the  following  notes  ;  but  it  must  be  remembered 
that  his  C.  pulchellus  is  not  the  true  pulchellus  of  Gray. 

"  If  this  shell  had  come  from  Central  America,  I  should  certainly 
have  regarded  it  as  C.  pulchellus  with  which  it  exactly  agrees  in 
sculpture,  number  of  ribs,  size  andstriation  of  the  scales,  and  general 
aspect.  Indeed  it  can  scarcely  be  separated  as  a  variety,  like  the 
Californian  shell.  Inside,  however  the  teeth  are  somewhat  sharper, 
one  of  them  having  an  extra  slit.  The  lamina  which  lines  the  sinus 
is  very  thin  and  sharp,  generally  (but  not  always)  marked  off'  from 
the  sutural  plates  by  slight  slits.  In  some  valves,  the  lines  which 
mark  it  off  are  perceptible,  but  they  do  not  serrate  the  edges.  It  is 
also  much  broader  in  some  valves  than  others.  Whether  the  species 
are  or  are  not  identical,  cannot  be  decided  from  the  single  specimen 
in  the  Smithsonian  Museum.  It  is  very  singular  that  a  shell  from 
equatorial  S.  America  should  be  replaced  by  a  very  distinct  species 
in  the  Bay  of  Panama,  should  reappear  in  the  Gulf  of  California,  be 
still  found  in  the  temperate  seas  of  California  and  lastly  display  a 
representation  on  the  shores  of  Japan."  (CJpr.) 

C.  ELENENSIS  Sowerby.     PL  59,  figs.  27,  28. 

Shell  oblong,  pallid  ;  back  rounded;  anterior  valve  radiately  sul- 
cate  ;  lateral  areas  of  the  intermediate  valves  swollen,  unisulcate; 
posterior  valve  retuse,  radially  sulcate  behind  ;  central  areas  of  the 
intermediate  valves  irregularly  sulcate-scabrous  ;  margin  smooth. 

Length  '6,  breadth  -3  inch.     (Sowb.*) 

St.  Elena  and  Panama. 


268  CALLISTOCHITON. 

Chiton  elenensis  SOWERBY,  P.  Z.  S.  1832,  p.  27.—  C.  ellinensis 
SOWB.,  Conchol.  Illustr.,  p.  6,  f.  69. — Ischnochiton  elenensis  CPR.,  P. 
Z.  S.  1865,  p.  275. — Probably  Chiton  janeirensis  var.f  GRAY,Spicil. 
Zool.,  not  of  Sowerby  and  Reeve. 

Sowerby's  original  description  and  figures  given  above.  I  have 
not  seen  this  species,  and  place  it  in  Callistochiton  with  some  doubt, 
as  its  internal  characters  may  demand  for  it  a  position  in  Ischno- 
chiton. Haddon  considers  it  very  closely  allied  to  C.  deeoratus  Cpr. 
Carpenter  has  identified  with  this  species  a  Panama  form  collected 
by  Prof.  C.  B.  Adams.  He  gives  the  following  description  of  it : 

"Outside  having  the  central  areas  decussated  with  about  20 
parallel  bars  ;  lateral  areas  having  two  strong,  swollen,  tuberculose 
ribs.  Interior  having  the  sutural  [posterior]  margin  reflexed, 
tuberculate,  with  a  small  sinus ;  insertion  plates  1-slit,  sinus  'very 
broad.  Front  valve  having  12  ribs,  not  very  strong,  and  ten  slits 
within,  the  teeth  acute,  eaves  narrow.  Posterior  valve  having  the 
mucro  subposterior,  depressed ;  the  slope  behind  it  expanded,  con- 
cave, with  about  12  subobsolete  ribs;  inside  with  9  slits,  the  teeth 
short,  eaves  small,  callous  within.  The  central  valves  of  this  species 
are  normal ;  but  the  posterior  valve  offers  a  transition  toward  Callo- 
chiton  L=Callistochiton],  the  outside  being  concave  posteriorly,  the 
insertion-teeth  short,  and  the  eaves  callous.  (Cpr.  in  P.  Z.  S.). 
The  sinus  is  unusually  broad  and  shallow,  the  sutural  laminse  not 
being  marked  off.  (Cpr.) 

C.  EXPRESSUS  Carpenter.     Unfigured. 

Shell  similar  to  /.  elenensis,  but  flesh-colored.  Central  areas  hav- 
ing 10  distant  closely  decussated  bars ;  dorsal  ridge  acute,  lateral 
areas  having  two  very  strong,  narrow  ribs  with  narrow  tubercles ; 
inside  having  the  posterior  margin  flat,  hardly  tuberculose,  hardly 
si  mi  a  ted  ;  sinus  narrow,  angulated  at  the  jugum.  Anterior  valve 
having  10  strong,  narrow  ribs;  interior  as  in  elenensis,  but  with  8 
slits.  Posterior  valve  having  a  flat  posterior  mucro,  the  slope 
behind  expanded,  hardly  concave,  with  about  7  very  strong  ribs; 
inside  having  about  7  slits,  the  eaves  flat. 

"  With  a  strong  general  resemblance  to  /.  e/>  //'  //x/x,  the  differences 
in  detail  in  the  only  two  specimens  examined,  as  above  stated, 
appear  of  specific  importance.  If  only  varietal,  it  is  equally  impor- 
tant to  notice  how  much  change  is  tolerated  by  the  habits  of  the 
animal.  It  may  be  the  shell  called  Cliilan  <-?at /trains  by  Professor 


269 

Adams,  of  whieh  there  were  no  duplicates  to  compare.  Jt  offers  a 
still  more  marked  transition  to  (<///,><•/, Iton,  the  mar-jin  of  the  pos- 
terior valve  l.eiiiLr  somewhat  pectinated  by  the  great  projection  of 
the  ribs.  (Q>r.) 

rnnama  (C.  B.  Ad.) 

Ischnochiton  (?  yar.)  expressus  CPR.,  P.  Z.  S.  1865,  j>.  'J7">. 

This  species,  like  the  last,  is  not  known  to  me  by  specimens,  the 
above  description  and  notes  being  from  Carpenter's  paper  in  the  P. 
Z.  S.  In  his  MSS.  Carpenter  places  it  in  the  smooth  scaled  section 
of  Inch  noch  Unit,  and  gives  some  additional  notes,  as  follows:  "This 
shell  is  almost  exactly  like  the  young  of  /.  serratus,  agreeing  not  only 
in  the  peculiar  and  beautiful  sculpture,  but  even  in  the  mantle  scales. 
Yet  it  differs  remarkably  in  the  abnormal,  narrow  pointed  sinus,  in 
which  respect  it  resembles  J.  tectiformis.  One  of  these  species  is 
probably  the  C.  clathratus  of  C.  B.  Ad.  (Pan.  shells,  p.  242),  and 
possibly  of  Reeve." 

C.  DECORATUS  Carpenter,  n.  sp.    PI.  58,  figs.  17-20. 

Shell  oblong,  moderately  convex,  obtusely  subangular  along  the 
dorsal  ridge,  the  side-slopes  slightly  convex.  Surface  rather  shining, 
varying  in  color  from  olive-buff  to  dark  green,  uniform  or  having 
darker  flammules  and  spots. 

Apices  of  the  median  valves  eroded.  Lateral  areas  raised,  each 
rendered  bicostate  by  a  central  sylcus,  and  having  a  few  uneven 
longitudinal  impressed  grooves,  giving  it  a  terraced  aspect.  Central 
areas  having  numerous  parallel  longitudinal  ribs,  the  intervals 
closely  latticed  across,  this  sculpture  obsolete  on  the  ridge,  where  there 
is  a  broad  V-shaped  smooth  area,  which  rarely  shows  a  few  diverging 
subobsolete  ribs.  Anterior  valve  having  11  rounded  ribs.  Posterior 
valve  less  elevated  than  the  anterior,  highest  at  the  front  margin,  the 
mucro  depressed,  post-median ;  posterior  area  having  9-10  rounded 
ribs. 

Interior  bluish,  generally  marked  with  olive  or  green  at  jugum, 
bases  of  the  sutural-plates,  and  slit- rays.  Sutural  plates  wide, 
separated  by  a  square  sinus  notched  at  each  side.  Anterior  valve 
having  9  or  11,  central  1,  posterior  valve  9-12  slits  ;  teeth  rather 
sharp,  smooth  ;  slit-rays  distinct  and  porous.  Eaves  narrow. 

Girdle  narrow,  ashy-brown,  covered  with  minute,  striated,  closely 
imbricating  scales. 

Length  20,  breadth  9-10  mill. ;  divergence  about  110°. 
Todos  Santos  Bay  and  near  San  Tomas  River,  Lower  Calif orn  in. 


270  rAI.USTui   HITON. 

CaUistochiton  cfoeorofti*  CPR.,  .I/NX. —  Chiton  (CaUistochiton)  decor- 
ati(s  Cpr.,  ORCUTT,  Proc.  U.  S.  Nat.  Mus.  viii,  p.  544  (1885,)  no 
description. 

It  has  been  reported  from  San  Diego  by  Orcutt  and  from  La  Paz 
by  Carpenter  (Pease  coll.) 

The  partially  sculptured  central  areas  are  peculiar  and  character- 
i-tic-,  and  the  tail  valve  presents  features  not  found  in  the  other 
species  of  the  same  region.  The  figures  17-20  may  be  regarded  as 
the  types,  but  some  individuals  show  some  very  obsolete  coarse  ribs 
in  the  front  part  of  thejugal  smooth  tract. 

The  type  is  in  the  collection  of  the  Academy. 

C.  GABBI  Pilsbry,  n.  sp.     PL  60,  figs.  7-10. 

Shell  oblong,  convex,  rather  sharply  carinated,  the  side-slopes 
somewhat  convex.  Surface  lusterless,  the  central  areas  light  brown, 
lateral  areas  olivaceous-brown. 

Median  valves  not  beaked  ;  lateral  areas  composed  of  two  strongly 
elevated  ribs,  bearing  acute  grains,  the  posterior  rib  wider,  having 
an  additional  row  of  smaller  grains  along  the  sutural  margin  ;  the 
suleus  between  the  ribs  rather  wide,  minutely  pitted.  Central  areas 
having  about  15  parallel  longitudinal  riblets,  becoming  diverging 
toward  the  outer  margins,  the  interstices  very  closely,  sharply  cross- 
latticed  ;  region  of  the  beaks  smoother,  pitted  and  microscopically 
granulate.  Anterior  valve  having  9  strongly  elevated  ribs  separated 
by  pitted  intervals  of  the  same  width  as  the  ribs,  the  latter  bearing 
acute  grains;  the  posterior  rib  on  each  side  wider,  with  sutural 
grains ;  region  of  the  beak  excavated.  Posterior  valve  elevated  at  the 
front  edge,  rapidly  sloping  backward,  the  mucro  about  c>  iitral,  much 
depressed;  posterior  area  sculptured  with  7  rather  broad  wave-like 
radiating  ribs  surmounted  by  acute  grains. 

Interior  light  olivaceous,  with  dark  markings  under  the  beaks. 
Sutural  plates  well  developed,  separated  by  a  narrow,  angular,  con- 
vex sinus.     Anterior  valve  having  9,  central  1,  posterior  valve  8 
slits ;  teeth  rather  short,  smooth,  festooned  and  slit  at  the  ribs.  L 
expect <tl I ij  in  the  tail  valve,  extremely  narrow. 

Girdle  covered  with  very  compactly  imbricated,  wide,  finely 
striated  scales,  which  are  arranged  in  alternate  patches  of  olive-bluish 
and  lighter,  the  light  patches  being  composed  of  mingled  bluish, 
tawny  and  white  scales  (fig.  7.) 

Lemrth  14,  breadth  8$  mill. ;  divergence  about  110°. 

Gulf  of  California  (Gabb.) 


«    \l  MM",    IHTON.  L'7 

In  the  depressed  inucro  ami  internal  colorim:,  a-  well  a-  tin-  nar- 
row eaves,  this  sp<  ;d»les  ('.  <l>r,,r<il  n.<  ( '|»r.  ;  but  t  he -ciilpt  u  r<- 
is  iiuicli  stronger,  and  i.~  nut  obsolete  at  the  dor>al  ridire  of  each 
valve.  The  (\  of  S..\vrrl»y,  a  species  which  I  have 
not  seen,  seems  to  be  similar,  bat  judging  from  Sowerl>y'>  figure  the 
nuiero  of  that  species  projects  at  the  summit  of  the  posterior  slope, 
which  is  far  from  bring  the  case  with  the  form  before  me.  The  form 
described  as  elenensis  by  Carpenter  differs  in  having  a  very  wide 
sinus,  weaker  sculpture,  etc.  It  should  be  compared  with  Carpenter's 
untiguivd  Inchnochiton  expressns,  a  species  not  known  to  me  autopt- 
ically. 

The  type  is  in  the  collection  of  the  Academy. 

C,  ITU  IIKLLUS  Gray.     PI.  60,  figs.  1-6. 

Shell  oblong,  rather  depressed,  the  dorsal  ridge  subangular,  side- 
slopes  convex.  Of  a  soiled  buff  color,  the  girdle  darker,  ashen. 

Valves  not  beaked ;  lateral  areas  raised,  cut  by  a  sulcus  into  two 
prominent  ribs,  of  which  the  posterior  is  wider,  sculptured  with  low, 
transversely  elongated  grains,  serrating  the  sutures,  the  anterior  rib 
having  less  conspicuous  grains.  Central  areas  in  the  middle  pitted 
in  diagonal  series,  the  pattern  becoming  coarser  on  each  side,  then 
changing  into  longitudinal  fine  riblets  on  the  outer  half  of  each  side. 
Anterior  valve  having  10  (or  12)  strong  rounded  ribs,  cut  into  low 
transverse  grains  by  superficial  concentric  impressed  lines.  Posterior 
valve  abruptly  depressed  at  the  mucro,  which  is  behind  the  middle,  the 
forward  area  level,  reticulated,  the  posterior  area  bearing  7  stout  ribs ; 
the  posterior  ones  are  strongly  bent. 

Interior  whitish  ;  sutural-plates  rounded,  separated  by  a  wide 
sinus,  which  is  angular  but  hardly  notched  at  the  sides,  and  not  per- 
ceptibly laminate.  Slits  in  head-valve  10,  median  valves  1,  poste- 
rior valve  about  14 ;  teeth  thin  but  normal  in  front  and  median, 
irregular  in  the  posterior  valve.  Eaves  narrow. 

Girdle  narrow,  densely  imbricated  ivith  minute  smooth,  flattened 
scales. 

Length  10,  breadth  5  mill.;  divergence  135°. 

Arica,  Chili  (Hennah.) 

Chiton  pulchellus  GRAY,  Spicilegia  Zoologica,  pt.  1,  p.  6,  t.  3,  f.  9, 
(July  1, 1828).— REEVE,  Conch.  Icon.,  t.  23,  f.  153  (?  and  perhaps  t. 
25,  f.  168).—  Chiton  (Callochiton)  pulclicllus  MORCH,  Mai.  Blat. 
vii,  p.  176. —  C.  bicoxtatus  D'ORBIGNY,  Voy.  dans  1'Amer.,  Merid.,  p. 
486,  t.  81,  figs.  7-9. 


L' ,  _'  CALLISTOCHITON. 

?  Chiton  pulchellus  C.  B.  AD.,  Cat.  Panama  Sh.,  p.  243  (in  part). 
— "  Chiton pulchellus "  CPR.,  P.  Z.  S.  1865,  p.  llS.—  Callistochitnn 
pukhri&r  CPR.,  J/N£ 

Not  Callistochiton  pulchellus  of  Carpenter's  M8S. — Not  Chiton. 
l>\ilchellus  of  d'Orbigny,  Voy.  dans  l'Ame*r.  Me*rid.,  p.  489. 

The  netted  sculpture  of  the  dorsal  areas  is  unlike  other  species 
from  the  western  coasts  of  the  Americas.  Figures  3-6,  drawn  by 
the  author,  should  enable  any  one  to  identify  the  species  readily. 
The  small  size  is  also  rather  characteristic,  as  well  as  the  profile  of 
the  posterior  valve  (fig.  5.) 

I  have  but  little  doubt  of  the  identity  of  Carpenter's  C.  pulchrior 
(=0. pulchellus  Cpr.,  P.  Z.  S.  1865,  p.  276)  with  the  true  C. 
rl,,!In8  of  Gray.  Carpenter  separated  pulchrior  from 
after  studying  specimens  supposed  to  be  of  the  latter  species  sent 
him  by  Cuming  ;  but  it  is  clear  to  me  that  Cuming's  identification 
was  erroneous,  and  therefore  the  position  taken  by  Carpenter 
becomes  untenable. 

Drawings  of  the  form  called  pulchrior,  prepared  for  Carpenter, 
are  reproduced  on  my  plate  59,  figs.  21-26.  The  sculpture  is  not 
well  rendered,  and  if  the  drawing  is  accurate,  the  tail-plate  differs 
somewhat  in  profile. 

Gray's  description  of  pulchellus  is  not  as  good  as  Reeve's  and  his 
figure  (pi.  60,  fig.  1)  is  poor.  The  detail  figure  given  by  Reeve  is 
copied  on  pi.  60,  fig.  2.  Gray's  description  is  as  follows : 

Shell  oblong,  ^elongate,  slightly  keeled,  yellowish-white.  End 
valves  distantly,  unequally,  radiately  ribbed;  lateral  areas  of 
the  middle  valves  with  two  broad,  regular  ribs ;  central  area  closely 
and  deeply  punctured.  Margin  yellowish- white,  with  very  minute 
bran-like  scales.  The  ribs  of  the  lateral  areas  are  rarely  bifid. 

Length  3,  breadth  i  of  an  inch.  [=about  9x4  mill.] 

Inhab.  Arica,  Peru,  Rev.  W.  Hennah,  Brit.  Mus.  (Gray.) 

The  species  described  from  Arica  by  d'Orbigny  is  in  all  pro  It- 
ability  the  same  as  Gray's  form,  but  the  figures  are  very  poor.  The 
original  description  is  here  translated  : 

C.  bicostatu*  d'Orbigny.  (PI.  59,  figs.  43,  44).  Shell  oblong, 
swollen  and  obtuse,  entirely  whitish.  Anterior  and  posterior  valves 
sculptured  with  broad,  radiating  ribs  and  some  concentric  lines  of 
growth.  Lateral  areas  of  the  intermediate  valves  each  ornamented 


(  \i  i  WTO  in 
•with    tWO    very    larirr,    prominent     ribs  ;    median  ide     and 

punctate.    Girdle  minutely  scaly.     Len^-tli  7  mill.    (0 

Arirn,  under  stones  at  l«»w  \v;r 

\lliedt"  r.  inilrlicf/im  of  < iray,  ditli-rmi:  in  tin-  irranulous  and 
scaly,  not  smooth,  Lrmlle,  1>\  the  two  ribs  ..i'the  lateral  areas  instead 
of  three,  and  hy  the  punctate  central  areas,  which  in  the  other 
species  are  striated."  (Orb.) 

It  must  l>e  remembered  that  the  "  C.  pulchellus  of  Gray"  alluded 
to  hy  Orhiirny,  is  not  tin-  true  jutlchellus  of  Gray,  but  some  totally 
ditieivnt  species  of  Chcetopleura  or  of  Tonic!". 

( '.  -in  ri  i. I:\VOKTHIANUS  Pilsbry,  n.  sp.     PL  21,  figs.  42,  43,  44,  4-">, 
4U. 

Shell  oval,  depressed  but  dorsally  carinated,  the  side-slopes  nearly 
straight;  lateral  areas  strongly  raised,  bicostate,  the  ribs  nodose; 
central  areas  having  a  coarse  raised  net-work  in  the  middle,  and 
longitudinally  ribbed  toward  the  sides.  Girdle  broad.  Color  of 
both  xliell  ami  yirdle  intense  orange  yellow. 

The  lateral  areas  bear  two  strong  ribs  which  bear  stout  transverse 
tubercles,  the  intervening  spaces  being  closely  granulate.  The  central 
areas  have  coarse  wi-likc  sculpture  (fig.  45),  which  becomes  much 
finer  toward  the  beaks,  and  is  transformed  into  a  longitudinal  cos- 
tulation  at  the  sides.  The  front  valve  has  16  or  17  strong,  tuberculate 
radiating  ribs,  the  whole  covered  by  a  fine  granulation.  The  poste- 
•"/?•'  />•  Depressed,  having  a  rather  low  but  acute  and  slightly  pos- 
terior mucro,  the  slope  back  of  it  being  concave.  It  is  sculptured 
similar  to  the  head-valve,  except  that  the  concentric  sculpture  pre- 
dominates over  the  radiating. 

The  interior  is  flesh-colored;  anterior  valve  with  10,  central  1 
slit;  sutural  plates  low  and  rounded  ;  sinus  shallow,  flat. 

Girdle  wide,  compact,  very  densely  clothed  with  closely  imbricat- 
ing scales,  the  terminations  of  which  are  not  striated,  although  the 
basal  portions  are  distinctly  grooved  (pi.  21,  fig.  46.) 

Length  14,  breadth  9  mill. 

Key  West,  Fl»ri<l,,  ,  Henry  Hemphill.) 

This  handsome  species  constitutes  one  of  the  links  between  Callis- 
tochiton  and  Ischnochiton,  agreeing  in  the  teeth  with  the  latter  genus. 
The  sculpture,  however,  is  much  more  like  Callistochiton  pnlcht  II us 
than  like  any  Ischnochiton  known  to  me ;  but,  on  the  other  hand, 
the  profile  of  the  tail-valve  differs  utterly  from  that  West  Coast 
species. 

18 


L'7  i  CALLI8TOCHITON. 

It  seems  to  resemble  the  unfigured  /.  lab'rithi*  Shuttlew.  in  color 

and  somewhat  in  sculpture;  but  Shuttleworth  says  of  his  species  "raids 

terminalibue  eubconcenbrice  lineatus  punctatisque ;  medii*  non  c<irin- 

etc.,  and  this  in  no  way  agrees  with  the  species  described 

above. 

The  type  is  in  the  collection  of  the  Academy. 

C.  ANTIQUUS  Reeve.     PL  59,  figs.  29,  30,  31,  32,  34,  35. 

Shell  oblong-elliptical,  moderately  convex,  obtusely  carinated,  the 
side-slopes  convex  ;  of  a  uniform  soiled  buff,  or  stained  with  reddish 
along  the  back  ;  sometimes  tinged  with  olive-green. 

Valves  not  beaked.  Lateral  areas  composed  of  two  strongly 
elevated  ribs,  bearing  compressed  grains,  the  posterior  rib  wider,  its 
grains  denticulating  the  suture.  Central  areas  having  a  honey-comb 
reticulation  near  the  beaks,  on  the  sides  changing  into  fine  longitu- 
dinal riblets  with  minutely  latticed  intervals.  Anterior  valve  hav- 
ing 11-12  very  strong,  rather  narrow  and  acutely  granose  ribs. 
Posterior  valve  depressed,  sloping  backward  from  the  front  margin, 
the  mucro  depressed,  slightly  in  front  of  the  center;  the  posterior 
area  having  8-9  strong  granose  ribs. 

Interior  bluish-white,  sutural  plates  low,  rounded,  separated  by  a 
broad  shallow  sinus.  Anterior  valve  having  9,  central  1,  posterior 
9  slits,  corresponding  to  the  external  ribs ;  teeth  smooth,  rather 
sharp,  curved  and  concave  outside  as  usual  in  Callistochiton.  Eaves 
rather  narrow. 

Girdle  wide,  thin,  leathery,  compactly  covered  with  very  small 
convex  and  apparently  smooth  brown  scales,  having  light  colored 
larger  scales  mingled  among  them  (fig.  34.) 

Length  17,  breadth  10  mill.;  divergence  110°-120°. 

Port  Molle,  Queensland  (Coppiuger),  Port  Jackson,  X.  S.  Wales 
(Angas,  Brazier,  Challenger.) 

Chiton  antiquus  REEVE.  Conch.  Icon.,  t.  25,  f.  169  (poor). — 
Lepidopleu/nu  antiquus  ANGAS,  P.  Z.  S.  1867,  p.  223. —  Callistochiton 
«////'/ /'//.-•  ('ri:.  MS.  and  HADDON,  Challenger  Polyplac.,  p.  20. — 
Chiton  (Git/ixtochif'ni')  anfiquus  E.  A.  SMITH,  Zool.  Coll.  'Alert'  p. 
79. —  Callistochiton  sarcophagus  CPR.,  J/> 

This  species  has  the  same  style  of  honey-comb  or  netted  sculpture 
toward  the  beaks  that  C.  pnlchellus  and  C.  shuttleworihianus  show. 
A  specimen  in  which  the  number  of  ribs  on  the  head  valve  is 
increased  by  splitting  to  17,  and  on  the  tail  valve  to  16  is  on  record; 


<   LLLWTCX  m 

bat  the  number  in  front  Ifl   ordinarily    from    into  1'J,   In-hind    from 
-8  to  ]-.     The  tail  valve  is  much  depre— ed,  as  in  (\  tjnl>hi. 

Carpenter  deseril>ed  a  Iarir<-,  line  speeimen  as  (  .  Mreophagut,  hut 
upon  examining  Ueeve's  type  he  concluded  that  it  was  merely  a  well 
developed  f//i//////i/x.  Tlie  type  is  in  the  Uritish  Museum. 

C.  coiM-iN<;i;i:i  Smith.      PI.  o<>,  fig.  36. 

Shell  elongate,  greenish-white,  stained  with  a  dark  green  color 
alonir  each  side  near  the  girdle,  with  a  paler  indistinct  stripe  on 
each  side  of  the  central  line,  the  apex  of  the  valves  heing  somewhat 
livid.  Central  valves  with  a  straight  posterior  margin,  arched,  with 
only  the  faintest  indication  of  a  carina  at  the  vertex.  Lateral  areas 
somewhat  raised,  with  two  radiating  rows  of  coarse  transverse 
rugse,  of  which  the  hinder  or  marginal  are  the  largest.  The  surface 
between  them  is  finely  granular.  Central  areas  covered  with  a 
more  or  less  criss-cross  granulation,  the  granules  at  the  center  being 
very  minute,  and  gradually  increasing  in  size  toward  the  sides, 
where  there  is  very  little  of  the  criss-cross  arrangement  seen  at  the 
vertex,  but  rather  a  longitudinal  disposition  of  them.  The  front 
valve  is  minutely  granulated  and  has  about  twenty  fine  radiating 
ridges,  here  and  there  some  of  them  bifurcating  near  the  circum- 
ference. Posterior  valve  rather  large,  concave  behind  the  sub- 
central  mucro,  in  front  of  which  the  surface  is  sculptured  in  the  same 
manner  as  the  front  of  the  central  valves,  as  is  usual  with  most,  if 
not  all  Chitons.  The  posterior  half  is  finely  grained  and  sparsely 
covered  with  pustules  of  different  shapes  and  sizes.  The  coarsest  being 
near  the  margin  and  the  smallest  near  the  center.  The  iusertioual 
plates  are  thin,  with  twelve  slits  in  the  last,  at  unequal  distances, 
eleven  in  the  front  one,  and  one  on  each  side  of  the  intermediate 
valves.  The  interior  is  pale  bluish,  the  latter  valves  having  an  olive- 
brown  stain  radiating  from  the  vertex  behind  on  each  side,  and  the 
two  terminal  valves  have  marks  of  the  same  color  near  the  middle. 

The  girdle  is  covered  with  alternately  pinkish  and  dark  grayish 
patches  of  fine  oval  compressed  imbricating  scales,  of  which  those 
toward  the  outer  margin  are  much  smaller  than  those  near  the 
valves. 

Length  without  girdle  21  millim. ;  diameter  of  fifth  central  plate 
8  mill.  (Smith.') 

Port  Jackson,  Australia  (Coppinger.) 

Chiton  (Callistochitoii)  coppinyeri  E.  A.  SMITH,  Rep.  Zool.  Coll. 
H.  M.  S.  'Alert,'  p.  80,  t.  6,  f.  E  (1884.) 


276  CALLISTOCHITON. 

The  only  published  figure  of  this  species  is  very  poor.  Smith 
writes :  closely  allied  to  C.  antiguus,  but  it  is  differently  and  more 
finely  sculptured,  and  the  scales  on  the  mantle  are  larger. 

The  type  is  in  the  British  Museum. 

C.  ADENENSIS  Smith.     PI.  59,  fig.  45. 

Shell  small,  depressed,  hardly  carinated,  unicolored  pale  brown- 
ish. Anterior  valve  having  about  22  granulate  radiating  ribs. 
Lateral  areas  composed  of  two  strong  granulate  ribs  ;  central  areas 
longitudinally  granose-lirate,  the  lirse  more  delicate  in  the  middle 
than  at  the  sides.  Posterior  valve  having  about  25  delicate  granulate 
lirce.  Girdle  pale  brownish,  very  minutely  scaly. 

Length  14,  breadth  9£  mill.     (Smith.') 

Aden. 

Chiton  (Callistochitoii)  adenensis  E.  A.  SMITH,  Proc.  Zool.  Soc. 
Lond.  1891,  p.  421,  t.  33,  f.  7. 

The  sculpture  of  this  species  is  of  the  same  character  as  that  of  C. 
antiguus  Reeve,  but  not  quite  so  pronounced,  and  the  rays  of  both 
the  terminal  valves  are  more  numerous.  (Smith.) 

The  type  is  in  the  British  Museum.  The  italics  of  the  above 
description  are  my  own. 

C.  HETERODON  Pilsbry,  n.  sp.     PI.  60,  figs.  11-15. 

Shell  oblong,  rather  elevated,  carinated,  the  side-slopes  nearly 
straight;  buff- white,  sparsely  dotted  on  the  ridge  with  olive-black 
and  having  one  or  two  spots  of  the  same  on  the  sides  of  each  valve ; 
the  girdle  yellowish,  having  narrow  slate-colored  bars. 

Valves  having  rather  acute  but  not  backward-projecting  beaks. 
Lateral  areas  raised,  having  3  or  4  ribs,  being  primarily  divided  by 
a  deep  sulcus  into  two  ribs,  the  posterior  of  which  is  again  divided  ; 
and  sometimes  the  front  rib  also  is  split  into  two,  especially  on  the 
second  valve ;  the  interstices  are  coarsely  pitted,  and  the  posterior 
rib  is  ribbed  across,  dentating  the  sutures.  The  central  areas  have 
about  11  rather  narrow  but  strong  longitudinal  riblets  on  each  side  of 
a  wider  dorsal  rib  ;  the  interstices  nearly  smooth.  Head  valve  having 
11  (or  13,  by  splitting)  strong  denticulate  ribs.  Tail  valve  narrower 
than  the  head-valve,  not  depressed,  the  mucro  obtuse,  post  median  ; 
posterior  slope  convex,  having  11  radiating  ribs. 

Interior  pure  white.  Sutural  plates  narrow,  separated  by  a  square, 
slightly  deticulate  sinus,  which  is  distinctly  laminate  and  slightly 
notched  at  the  corners.  Anterior  valve  having  8,  central  valves  1, 


NUTTAI.MNA.  277 

posterior  valve  13  slits  ;  teHh  blunt,  finely  and  deeply  pectinated  out- 
side and  at  the  edge.     Eaves  solid. 

<  Girdle  broad,  compactly  covered  with  shining,  deeply  sulcated 
scales,  measuring  about  one-third  of  ;i  mi  Him.  in  breadth,  and  the 
terminal  margin  of  each  is  smooth  (fig.  13.) 

Length  about  16,  breadth  10  mill. ;  divergence  about  105°. 

Red  Sea. 

This  species  has  far  fewer  ribs  on  the  terminal  valves  than  C. 
adenensis  Smith,  although  the  lateral  areas  have  more  ribs.  The 
girdle  scales  are  coarser  than  in  other  species,  and  they  have  the 
peculiarity  noted  in  C.  shuttleworthianus,  of  being  smooth  at  the 
distal  end.  I  have  seen  no  Chitons  of  other  genera  having  this 
feature.  The  second  valve  has  several  slightly  diverging  riblets  at 
the  front  of  the  dorsal  area.  The  teeth  are  as  deeply  pectinated  as 
in  any  species  of  typical  Chiton  or  Acanthopleura ;  and  it  is  by  no 
means  impossible  that  the  species  belongs  to  the  former  genus.  I 
have  preferred  to  retain  it  in  Callistochiton  on  account  of  the  peculiar 
sculpture,  and  the  relation  in  which  the  slits  stand  to  the  ribs. 

The  type  is  in  the  collection  of  the  Academy. 

Var.  SAVIGNYI  Pilsbry.     PL  60,  fig.  16. 

This  form  is  known  to  me  by  Savigny's  figures,  which  indicate  a 
species  closely  resembling  the  last.  The  head  valve  has  11,  the 
lateral  areas  two  ribs ;  the  tail  valve  is  smaller,  having  9  ribs ; 
central  areas  with  about  9  ribs  on  each  side,  and  a  rather  wide 
smooth  tract  in  the  middle.  Scales  of  the  girdle  sulcate,  with 
.smooth  outer  edges. 

SAVIGNY,  Descript.  de  FAegypte,  Gasterop.,  t.  3,  f.  8-1,  8-2,  8'3. 

Genus  XXIV.     NUTTALLINA  Carpenter,  1879. 

=Nuttallina  plus  Middendorfia  plus  Beanella  Cpr. 

Valves  exposed,  granulated,  the  lateral  areas  having  2,  head 
yalve  numerous  low  radiating  ribs ;  insertion-plates  sharp,  the  slits 
corresponding  in  position  to  external  ribs*  Mucro  behind  the 
middle,  the  posterior  teeth  directed  forward.  Eaves  and  sinus  very 
spongy.  Girdle  varying  from  spiny  to  scaly. 

This  well-defined  genus  probably  has  the  same  apparently 
anomalous  distribution  as  the  coral-red  Leptothyras ;  species  being 
found  in  the  Mediterranean,  the  Japanese  Seas,  and  the  coast  of  Cali- 


278  Nl-TTAI.l.INA. 

i'oniia.     Xuttallina  is  divisible  into  two  closely  allied  sections  or  sub- 
genera,  as  follow- : 

Siihuvniis  Xn  I'M. i. IN  A  .*.  str.  Side-slits  two  in  each  valve,  the  pos- 
terior one  generally  subobsolete,  but  indicated  by  a  porous  slit- 
ray.  Teeth  hardly  or  not  thickened  at  the  edges  of  the  >lits  ; 
girdle  wnh  minute,  often  chaffy  spinelets  and  longer  round  spines. 

Sul  .genus  MIDDENDORFFIA  Cpr.     Side-slits  single.      Teeth  more  or 
--  thickened  at  the  edges;  girdle  clothed  with  minute  striated 
flattened   scales   and   having   a    marginal    row   of  flat  striated 
bristles. 

Subgenus  NUTVALLIXA  Carpenter  (restricted.) 

Xiitt'illina  CPR.,  Table  of  Reg.  Chitons,  1873.— DALL,  (Amer. 
Journ.  Conch,  vii,  p.  134),  Proc.  U.  S.  Nat.  Mus.  1878,  p.  333 
(Feb.  14,  1879.) 

Valves  exposed,  granulated,  having  long  smooth  sharp  teeth  ;  the 
slits  of  the  median  valves  obsoletely  doubled, 'those  of  the  anterior 
valve  corresponding  in  position  to  the  external  ribs,  the  teeth  not 
thickened  at  the  edges  of  the  slits;  mucro  of  posterior  valve  poste- 
rior, terminal  but  not  marginal;  teeth  of  posterior  valve  short, 
chisel-shaped,  directed  forward.  Eaves  and  sinus  spongy.  Girdle 
bearing  short,  rigid  spines.  Gills  extending  the  whole  length  of  the 
foot.  Type  X.  scabra  Cpr.=  CA.  californiciis  (Nutt.)  Rve. 

The  shell  in  this  genus  resembles  that  of  typical  Acanthophnrn 
(A.  spinosa  Brug.)  in  the  elongated  valves,  double  slitting  of  the 
median  valves,  and  the  spinose  girdle.  It  differs  in  the  smoothness 
of  the  sharp  teeth  and  the  spongy  sinus, — characters  of  much  greater 
importance  than  those  first  enumerated.  The  likeness  of  Nuttallina 
to  Acanthopleura  is,  in  fact,  merely  one  of  analogy,  having  no  mean- 
ing deeper  than  that  story  of  the  development  of  different  stocks 
along  parallel  lines,  repeated  so  often  in  the  history  of  Chitons.  In 
its  fundamental  characters,  Nuttallina  agrees  with  Ceratozona ;  but 
the  more  shelly  texture  of  the  girdle-spines,  the  spongy  sinus, 
and  propless  teeth  afford  sufficient  ground  for  generic  distinction. 

Authors  and  collectors  have  gnu-rally  recognized  but  one  Cali- 
fornia species ;  but  there  seem  to  be  two.  It  is  useless  to  try  to 
.-tudy  thnn  without  separating  the  valve?,  as  the  specific  characters 
are  not  very  apparent  in  specimens  preserved  in  the  ordinary 
manner. 


279 

Tin-  white  -piiM--  are  oftm  ^trialed  when  JOUllg,    as  are  the  scale- 

•///•/. 

N.CAI  ii <H;\ICA  Nuttall.     PI.  -VI,  lii-.  '-'::,  24;  |.l.  56,  fiir.  IL' 

1  l,  15,  16;  17,18. 

Shell  elongated,  more  than  twice  as  long  as  wide,  moderately 
elevated,  carinated  or  somewhat  rounded.  Surface  finely  «-Mrru^ated- 
irranular,  lusterless ;  color  dark  brown,  dark  olive-brown  or  Idack- 
ish,  unicolored  or  having  one  or  three  whitish  stripes  along  the 
summit  of  the  second  valve. 

Median  valves  strongly  beaked,  v-shaped,  the  anterior  margin  of 
the  tegmentum  trilobed;  having  a  smooth  shining  rounded  dorsal 
ridge  (sometimes  obsolete  and  often  eroded),  bounded  by  a  pair  of 
<lii'''i-giiif/,  shallow  furrows ;  the  entire  sides  of  the  valve*  <  />/'  "/•'/  <nid 
lateral  areas)  closely  granulated,  the  granules  irregularly  arranged 
in  rows.  Lateral  areas  not  raised  but  indicated  by  a  low  curved 
diagonal  rib,  behind  which  and  parallel  to  it,  there  is  a  shallow 
sulcus.  Anterior  valve  having  11  low  rounded  radiating  ribs,  the 
entire  surface  granulated.  Posterior  valve  depressed,  small,  the 
mucro  posterior  and  terminal,  projecting  beyond  the  posterior  margin 
of  the  eaves. 

Interior  bluish,  sometimes  stained  with  blackish  at  jugum  and 
bases  of  the  sutural  plates.  Sutural  plates  very  long,  separated  by  a 
wide,  deep,  square  sinus;  behind  which  is  a  punctate  and  I'm 
area.  Anterior  valve  having  11  or  10,  median  valves  with  two  slits, 
or  at  least  two  punctulate  slit-rays,  the  posterior  slit  being  usually 
indistinct  or  wanting  from  the  more  or  less  complete  obsolescence  of 
the  posterior  tooth ;  teeth  sharp,  smooth,  long,  not  thickened  at  the 
edges  of  the  slits.  Posterior  valve  having  8-9  slits,  the  teeth  chisel- 
shaped,  sharp,  smooth,  very  strongly  directed  forward.  Eaves  nar- 
row, spongy. 

Girdle  closely  covered  with  short,  rigid  calcareo-corneous  spine- 
lets,  mostly  of  a  scorched  brown  color  with  a  few  white  spines  inter- 
mingled (pi.  54,  fig.  24.) 

Length  37,  breadth  15  mill.     (Large  specimen  from  Monterey.) 

Length  26,  breadth  13 £  mill.     (Specimen  collected  by  Nuttall.) 

Vancouver  Island  south  to  Piedras  Blancas,  near  S.  Simeon,  San 
Luis  Obispo  Co.,  California. 

Chiton  californicus  NUTTALL  in  Brit.  Mus.  and  Mus.  Phila. 
Acad. — REEVE,  Conch.  Icon.,  pi.  xvi,  fig.  89  (March,  1847).— 


280  NUTTAI.I.INA. 


.«>nl>rn  On.,  MS.  and  of  BALL,  Amer.  Journ.  Conch,  vii,  p. 
184;  Proc.  U.  S.  Nat.  Mus.  1878,  p.  333.—  AcauthofL-ura  scabra  OK., 
Ilrit.  Asso.  1863,  p.  649.—  STEARNS,  Proc.  Calif.  Acad.  iii,  p. 
346.—  Nutt'ill',,,,,.,  Mdbra  Kr.r.r.  West  Coast  Shells,  p.  108,  f.  96 
(1887.)     Not  Chiton  scnber  Reeve. 

This  is  the  form  which  has  generally  been  called  "JV.  scabra." 
Reeve's  figure  is  not  good,  being  drawn  from  a  short  specimen 
abnormally  shortened  by  contraction.  It  should  be  noted  that  the 
shortest  specimen  in  the  large  suite  before  me  is  also  one  of  those 
collected  by  Nut  tall,  who  presented  a  complete  set  of  iiis  Califor- 
nian  shells  to  the  Academy. 

In  this  species  the  individual  valves  are  longer  than  in  the  follow- 
ing form,  but  on  account  of  their  deep  imbrication  the  difference  is 
not  in  most  cases  noticeable  until  the  shell  is  dissected.  The  girdle 
is  much  more  densely  clothed  with  spinelets. 

The  areas  of  distribution  seem  to  be  separated,  the  true  californica 
extending  southward  past  Monterey  Bay,  —  the  southern  out-post  of 
so  many  species  of  the  Columbian  district,  —  to  near  S.  Simeon,  S. 
Luis  Obispo  Co.  The  other  species,  scabra,  has  not  been  noticed 
north  of  Sta.  Barbara  Island,  and  San  Diego  on  the  mainland. 
There  is  still  a  considerable  stretch  of  coast  from  which  we  have  no 
record,  or  at  least  no  record  in  which  the  two  forms  are  discrimin- 
ated. This  coast  should  be  searched  for  intermediate  forms. 

Dall  gives  the  following  notes  on  the  station  of  this  form  :  This 
r-iniriilar  species  (not  yet  obtained  from  Alaska,  but  which  will  prob- 
ably be  found  there),  like  some  Lilorinas,  seems  habitually  to  prefer 
positions  where  it  can  at  most  be  reached  by  the  spray  in  stornis,  on 
-ed  headlands,  where  the  breeze  comes  in  damp  and  cool  from 
the  sea.  The  pointed  valves  overlap  each  other  so  much  that  when 
the  creature  is  curled  up  they  project  from  the  girdle,  giving  a  pect- 
inated outline,  unusual  in  Chitons.  The  valves  are  almost  always 
eroded,  even  the  prominent  mucro  is  often  hollowed  out,  and  the 
sculpture  can  rarely  be  seen  except  in  young  specimens.  The  color 
i.-  irrayMi  «>r  l>n>wni.-h.  with  whitish  streaks;  the  girdle  has  the 
aspect  of  dead  brownish-black  moss,  sometimes  with  ashy  spots  at 
the  sutures. 

N.  SCABRA  Reeve.     I  'I.  :>  J,  figs.  21,  22  ;  plate  56,  figs.  19,  20. 

Shell  similar  to  N.  californiea,  but  having  the  individual    valves 

much  shorter  in  proportion  to  their  width  :  the  outer  layer  of 

the  median  valves  produced  at  the  sides  anteriorly,  curving  broadly 


M  i  i  \  i  i  281 

forward    and  literally  Upon  thfl   sutural    plat<--;   flu-    medi;m     i 
and  sulci  inoiv   or  •  !••.       'I  ail  valve   -li'Ti.r,  with  less  pos- 

terior macro,    Oolor  of  yalvei  li.irht  vaiir-at.'d. 

Girdle   rusty  brown  or  alternately    blacki-h    and    white  ; 
rather  spar-ely  scattered  white   sj)ik«--lik<-  -j.i  • 
one  or  two  at  each  suture.       PI.  ">J,  fig.  21).     length  :>!»,  breadth 
L3  mill. 


Santa  Barbara  Is.  ami  XHH  I>i»/()to  between  Soo/mn 

<Ul<I    rtd.  tie   -1  /'/V»»/'f*S,    Jjnir,,-   (  'il/ifi>rn  i'l  . 

Chiton  scaber  h'u.vi:.  Conch.  Icon.,  t.  17,  f.  106  (March,  1847).— 
Acanthopleura  fluxa  CPR.,  Suppl.  Rep.  Brit.  Asso.  1863,  p.  649; 
Proc.  Cal.  Acad.  iii,  {>.  211,  (1865.) 

This  species  has  hitherto  been  confused  with  the  preceding  by 
most  collectors.  Carpenter,  however,  distinguished  it,  and  gave  the 
name  fliu-n.  Although  the  individual  valves  are  much  shorter  in 
this  species  than  in  N.  californica,  they  overlap  much  less,  so  that 
the  total  length  of  the  animal  is  about  the  same  in  the  two  species. 
The  elevation  is  about  equal  also,  but  in  californica  the  girdle  is 
generally  wider  at  the  sides,  especially  in  old  specimens.  In  size, 
individuals  of  the  northern  species  considerably  exceed  any  of  the 
southern  I  have  seen,  although  the  majority  of  specimens  do  not 

differ  much. 

• 

N.  ALTERNATA  Sowerbj.     PL  54,  figs.  25,  26,  27. 

Shell  elongated,  subdepressed,  very  minutely  granulated  ;  lightly 
keeled  by  a  central  rib  ;  lateral  areas  separated  by  a  lateral  rib. 
Anterior  valve  radiately  ribbed  ;  posterior  valve  small. 

Girdle  furnished  with  minute  spines,  alternately  banded  black 
and  white.  Length  15,  breadth  8£  mill. 

Narrow,  rather  flat,  minutely  granulated;  the  first  valve  radiated 
•with  slightly  raised  ribs,  the  intermediate  have  each  three  faint 
ribs,  one  dorsal,  the  other  two  lateral  ;  the  la>t  U  very  small,  with 
a  nearly  terminal  apex.  The  margin  is  covered  with  very  minute 
spines,  in  alternate  patches  of  black  and  white;  general  color,  dark 
olive-green.  (Sowb.) 

(Mus.  (  'inning). 


Chiton  alternatus  Sown.,  Mair.  of  Nat.  Hist.,  IMn,  p.  288  ;  Conch. 
Illustr.,  f.  141. 


282  \  I.I.I  N  A. 

This  form  has  not  been  noticed  by  subsequent  authors.  It  seems- 
to  agree  with  the  preceding  species  in  the  dorsal  and  lateral  ribs, 
and  also  those  upon  the  anterior  valve ;  but  as  the  interior  is 
unknown,  its  reference  to  Xntt<t/lina  is  provisional. 

Subgenus  MIDDENDORFFIA  Carpenter,  1882. 

ir  <  , /,,/ym  CPR.,  MS.  and  in  DALL,  Proc.  U.  S.  Nat.  Mu>., 
1881,  pp.  284,  287,  type  Chiton  polii  Phil,  non  Desh.,  (Jan.  20, 
1882.) — Dawsonia  CPR.  1873,  preoc.,  same  type. — Beania  CPR. 
3/5.,  not  of  Johnstone. — Beanella  DALL,  Proc.  U.  S.  Nat.  Mus. 
1881,  pp.  284,  287,  type  C.pseudorissoi  CPR.  ined.,  in  Mus.  Cuming 
no.  51. 

Valves  exposed,  rather  square  and  short,  granose  outside  with 
low  ribs  at  lateral  areas  and  on  head- valve.  Insertion  plates  rather 
sharp,  not  notably  rugose,  the  teeth  more  or  less  thickened  outside  at 
the  slit-edges;  slits  of  head-valve  corresponding  in  position  to  exter- 
nal ribs.  Tail  valve  small  with  mucro  behind  the  center,  the  teeth 
directed  forward,  eaves  and  sinus  coarsely  spongy.  Girdle  narrow, 
compactly  covered  with  a  pavement  of  minute  striated  scales  and 
spinose  at  the  edge.  Gills  extending  forward  over  three-fourths  the 
length  of  the  foot.  Type  Ch.  cinerem  Poli,  not  Linn. 

This  subgenus  agrees  with  Nnttallina  in  the  markedly  porous  or 
spongy  texture  of  eaves  and  sinus,  in  the  external  sculpture,  and  in 
the  forms  of  the  insertion-teeth,  except  that  in  Middendvrffia  these 
are  thickened  at  the  slit-edges.  It  differs  from  Nuttallina  in  the 
rather  flattened  scale-like,  rather  than  spine-like  girdle  appendages 
but  the  younger  spines  of  Nutallina  scabra,  when  examined  under  a 
strong  power  are  often  seen  to  be  striated,  appearing  like  finely 
fluted  ivory  pillars ;  and  in  some  specimens  of  the  same  species 
there  is  a  marked  tendency  to  form  a  marginal  fringe  of  longer 
spines.  The  differences  between  the  West  American  and  Med- 
iterranean forms  are  therefore  not  great,  being  confined  to  (a)  the 
irinlle  covering,  which  often  varies  as  much  in  closely  allied  species, 
such  as  ItehnockUon  r,tn*i>'n-im*  and  /.m-rior,  or  Chatopleuraperwri- 
<in<i  and  C.  henna  hi,  and  (6)  the  thickened  tooth-edges,  which 
varies  considerable  in  Mid>l,  ndorffia  and  fails  as  a  generic  charac- 
ter in  Ceratozona  and  some  other  groups. 

It  should  be  noted  that  in  Middendorffia  the  true  structure  and 
especially  the  sculpturing  of  the  girdle-scales  often  cannot  be  satis- 
factorily observed  without  a  compound  mici  . nd  a  magnifi- 


cation  of  Iron  i  ."in  to  MM)  diain«'trr-  is  neC€80ary  to  deHMMIttntfl  it  iii 
many 


N.CMVI  :i:i  :\   IMi.      IM.  54,  flg&  20 

Shell  oval,  moderately  elevated,  not  earinated,  tin-  ^ide  slope* 
straight.  Surtaee  lii>t»-rl«s<,  ur«'ii.  -rally  enerusted  with  ealrareous 
IT  n>  wths,  gray  or  greenish  blotched  with  Mack  or  dark  green  uitli 
some  liirht  marking  or  liirlit  va! 

The  median  valves  arc  beaked  when  young,  but  eroded  and 
hardly  beaked  when  adult,  the  lateral  <i  d  lmt  w>i 

Itiftwo/inr  iride  rounded  r/Ax  with  a  shallow  depression  between  them  ; 
one  rib  diagonal,  the  other  at  the  posterior  border.  Entire  surface 
of  all  valves  rrenh/  n>r>  rc<!  with  comparatively  coarse  i/ru/iutes. 
Anterior  valve  having  8  or  9  low  rounded  radiating  ribs.  Posterior 
I'n  /re  very  small,  the  mucro  somewhat  behind  the  center,  the  slope 
behind  it  straight  ^posterior  mart/in  cni<i,-</in>if>  (ai  in  Kudoxochiton, 
p.  193.) 

Interior  bluish  in  the  middle,  olive-greenish  at  the  sides.  $•' 
rather  deep  and  amju/nr,  t'trif  jinnm*  »/•  .-•/"'  ".'///•  A  more  or  less 
distinct  laminate  triangle  extending  from  sinus  to  beak.  Anterior 
valve  having  8  or  9  slits  corresponding  in  position  to  the  external 
ribs  ;  the  slits  are  very  short,  but  are  continued  as  grooves  to  the 
eaves  outside  ;  median  valves  with  1  slit  ;  the  anterior  teeth  nearly 
smooth,  distinctly  thickened  or  "  propped"  outside  at  the  slits;  pos- 
terior valve  having  slits,  the  teeth  rather  stumpy,  short  in  the  mid- 
dle behindj  longer  and  directed  forward  at  the  sides.  Eaves  rather 
wide  and  coarsely  spongy. 

Girdle  narrow,  alternately  dark  and  light,  compactly  covered 
with  small,  subcircular  or  irregularly  polygonal  scales,  striated  on 
the  convex  outer  surface,  crowded  together;  the  margin  beset  with  a 
series  of  slightly  flattened,  striated  translucent  bristles,  (figs.  31,  33). 

Length  14,  breadth  8  mill. 

Length  20,  breadth  12  mill. 

Entire  Mediterranean  and  Adriatic  Seas;  Atlantic  Ocean  at 
Cadiz,  Spain.  Littoral  zone. 

Chiton    i-'niereus  (+  Lophi/rn.^   nnlphlctensis)    POLI,    Test.    utr. 
Sicil.  i,  multivalvia  p.  4,  t.  ?>,  f.  1-20,  (1791).      Not   C.   eta 
Linn.  —  C.  capreann  SCACCHI,  Cat.  Conch.  Regni   Neapolitan!,  p.  9 
(1836)  teste  Monts.  —  C.  caprearum  Scac.,  BUG.,  DAUTZ.  and  DOI.I.- 
FUS,  Moll.  Mar.  Rouss.  i,  p.  492,  t.  61,  f.  7-9  ;  t.  62,  f.  1  (1886).— 


284  NUTTAI.I.INA. 

Ch.  polii  PHIUI-IM,  Knuni.  Moll.  Sicil.  i,  p.  106  (1836);  ii,  p.  83 
(1844),  and  of  most  subsequent  authors ;  not  Ch.  polii  Desh.  1832. 
—  Ch.  crenulatus  LOCARD,  Coq.  Mar.  des  Cotes  de  France,  p.  233. 
(1892),  and  perhaps  C.erenulatusHiaQ  Ear. Mend.  p.  267. —  Chiton 
TII-.KRI,  Bull.  Soc.  Mai.  Ital.  iii,  p.  141  (1877).—  Chiton 
"  Ki  i :\  i:  Conch.  Icon.,  t.  28,  f.  185  (1848). 

Distinguished  from  other  Mediterranean  species  by  the  finely 
granose- scaly  sculpture  covering  the  entire  surface,  with  two  low 
ribs  at  the  lateral  areas  and  8  or  9  on  the  head-valve.  The  girdle 
is  composed  of  short  striated  scales  crowded  together,  producing  a 
"  cobble-stone  pavement  "  surface.  The  true  nature  of  the  scales 
appears  only  when  highly  magnified.  The  nomenclature  of  the 
species  is  peculiarly  involved,  like  that  of  most  Mediterranean  Chi- 
tons. Poli  believed  it  to  be  the  cinereus  of  Linnaeus,  but  Philippi  dis- 
tinguished it  from  that  and  gave  the  name  Polii,  which  unfor- 
tunately had  been  some  years  before  bestowed  by  Deshayes  upon 
another  species.  Monterosato  claims  to  have  identified  it  with  Ch. 
eapreftrum  ("  caprearm  ")  of  Scacchi,  by  examination  of  a  type  in 
the  Petit  collection  ;  but  the  description  given  by  Scacchi  is 
inadequate.  Scacchi  says :  "  Chiton  caprearm  [sic]  Nobis.  Clypeis 
8  tuberculatis  virescentibus,  fascia  marginali  squamoso~muri<-'if<i, 
perbelle  ciliata.  Longus  lin.  6,  latns  I  in.  41.  Caprearum  scopulos 
incolit. ''  Locard  identifies  it  with  crenulatus  Risso,  the  original 
description  of  which  follows:  "  C.  crenulatus.  Dorso  segmentis  omul- 
bus  cinereis  crenulatis,  Long.  17  mill.  Penn.  Br.  Zool.  4,  JOTAT/, 
3,  Pol,  4,  Hi.  fn.  Of  course  this  may  be  the  present  species,  but  the 
wretched  description,  without  a  figure  is  quite  unacceptable.  Tiberi 
proposed  the  name  Ch.  decipiens  as  a  substitute  for  polii  Phil,  not 
Desh.  The  locality  of  Reeve's  Ch.  corrni/ntiis  is  not  known,  but  the 
description  and  figures  render  its  identity  reasonably  certain,  and 
Carpenter  declares  the  types  to  be  young  polii  Ph.  In  the  midst  of 
so  many  conflicting  names  and  opinions  I  prefer  to  retain  the  name 
given  by  Poli.  His  description  is  infinitely  better  than  any  of  the 
later  ones  mentioned  above.  Indeed  Poll's  work  upon  this  species  is 
wonderful  for  his  time,  and  with  such  an  example  before  them  it  is 
surprising  that  BO  many  Mediterranean  naturalists  have  K-lt  such 
miserable  work. 

It  is  needless  to  say  that  the  Chitnn  <-in, ,-,  //.,  (}{'  Limn'  belongs  to  a 
genus  which  must  be  admitted  by  all  naturalists  who  examine  the 
subject,  to  be  perfectly  distinct. 


•  i:  \-ri:  1 1 « .(in 

The  representation  «»t'  iln-  course  port-  of  tin-  eavea   in  ti^.  28 

cause-  the  toeth  to  :i|.|.r:ir  pectinated,  which  i.-  l.y  IIM  metDl  tin- case. 
Vnr.  ji.fwlnri**'!  Cpr.     Teeth  <•!'  insertion  hardly  thick,  n,,|  ;it  the 

edges;    inucro    Bubmedian ;    Birdie    scales    elongated,    flattened, 

striated, 

Matia. 

The  type  is  no.  51  of  Mus.  Cumin;:.  (1arpenter,  after  examining 
more  material,  decided  that  this  form  was  specifically  identical 
with  the  Ch.  poln  Phil.  His  type  specimen  is  a  young  shell.  Not 
having  seen  it,  I  inn  unable  to  tell  whether  all  of  the  scales,  or  only 
those  at  the  edge  are  elongated.  In  either  case  the  subgeneric  name 
Beania  or  Beanella  falls  as  a  synonym. 

Genus  XXV.    CRASPEDOCHITON  Shuttleworth,  18 

Craspedochiton  SHUTTLEW.,  Bern.  Mittheil.  1853,  p.  67.      Type 

C1//.  laqneutits. 

Valves  exposed,  slightly  immersed,  granulated  ;  with  five  low  ribs 
on  the  head-valve  ;  insertion  plates  sharp-edged ;  those  of  anterior 
valve  long,  strongly  grooved  inside  and  out,  having  slits  at  the 
positions  of  the  external  ribs  ;  median  valves  having  the  insertion 
plates  thin,  sharp,  1-slit;  posterior  valve  with  subcentral  mucro, 
teeth  short,  grooved.  Girdle  corneous,  very  minutely  roughened. 

The  characters  of  eaves  and  sinus  are  unknown  to  me.  The 
external  sculpture  reminds  one  of  Nuttallina,  which  differs  in  the 
posterior  mucro,  etc.  The  sharp-edged  insertion  plates,  and  the 
correspondence  of  slits  to  external  ribs  show  clearly  that  this  genus 
does  not  belong  in  the  neigborhood  of  Chiton,  Tonicia,  etc.,  where 
Carpenter  placed  it,  but  with  the  genera  here  accompanying  it 
which  share  these  peculiarities. 

C.  LAQUEATUS  Sowerby.     PI.  39,  figs.  42-51  ;  pi.  44,  fig.  68. 

Shell  ovate,  depressed,  granulated;  pale,  tawny  or  greenish, 
maculated  with  purple  or  green ;  the  dorsal  rib  purple. 

Anterior  valve  having  five  low  ribs,  median  valves  squared  at 
the  ends,  and  having  the  sculpture  often  worn  from  the  median 
ridge,  which  is  wedge-shaped  on  each  valve,  the  wedge  being  com- 
posed of  about  six  truncated,  somewhat  wedged  segments,  and  on 
each  side  there  are  oblique,  irregular  ridges.  Posterior  valve  having 
the  mucro  central  and  very  little  raised. 


286  ANGASIA. 

Interior  :  . \nt.-rior  valve  (figs.  43,  44,  45)  considerably  thickened 
within,  ;ui*l  shallowly  grooved  radially  ;  the  insertion  plate  stout  at 
the  base,  acute  at  the  edge,  and  furrowed  both  inside  and  out,  the 
edge  consequently  being  roughly  crenulated;  slits  5,  corresponding 
in  position  to  the  external  ribs.  Median  valves  (figs.  46,  47,  48) 
havin.ir  broad  and  thin  insertion  plates,  which  are  smooth-edged, 
and  only  very  finely  striated.  Posterior  valve  (figs.  49,  50,  51) 
having  the  insertion  plate  very  short,  thick,  moderately  sharp-edged 
coarsely  grooved  within  and  without,  and  roughly  crenulated  on  the 
margin.  AVhen  viewed  from  above  (the  valve  resting  upon  a  flat 
surface)  the  teeth  are  not  visible,  and  all  touch  the  surface,  there 
bi-in.ir  n<>  upward  wave  posteriorly. 

Girdle  coriaceous  (or  perhaps  better,  pithy)  and  almost  smooth. 

Length  LSI,  hivadth  Hi  mill. 

Calapan,  Island  of  Mindoro,  Philippines,  in  coarse  sand  among 
small  stones,  in  9  fms.  (Guming.) 

Chiton  laqueatus  Sows.,  P.  Z.  S.  1841,  p.  104.— REEVE,  Conch. 
Icon.,  t.  20,  f.  135. 

The  above  description  is  mainly  compiled  from  details  furnished 
by  Mr.  E.  A.  Smith  of  the  British  Museum,  who  also  drew  figures  42 
-51  from  one  of  the  original  specimens.  The  scale-like  granules  are 
said  to  be  represented  somewhat  too  small  on  the  figures.  Sowerby 
remarks  that  the  four  or  five  central  valves  in  several  specimens  are 
nearly  covered  by  a  dark  purple  color,  the  two  last  patched  with 
green,  and  the  first  nearly  white,  but  subject  to  some  variations. 
Slmttlcuorth  describes  the  girdle  "  limbus  corneus,  minuti 
atperulus,"  but  Smith  says  it  is  nearly  smooth  in  the  British 
Museum  specimens,  and  the  insertion  plates  are  visible  through  it, 
as  shown  in  fig.  42. 

Genus  XXVI.     A XGASIA  Carpenter,  1882. 

Angasia  CPR.,  Table  Reg.  Chitons  1873  ;  and  in  DALL,  Proc.  U. 
S.  Nat.  MusM  1881,  p.  283,  286,  289,  290  (Jan.  20, 1882).— Augasia 
SCUDDER,  Nomencl.  Zool.  p.  38  (typog.  err). 

Valves  outwardly  and  within  like  those  of  Chwtopleura,  but  the 
eaves  small ;  girdle  minutely  scaly-pilose,  and  furnished  with  tufts 
of  hairs  at  the  sutures.  Type  A.  tdrica  Cpr. 

I  have  seen  no  specimen  of  this  form,  which  I  believe  to  be 
related  to  Oraspedochiton,  Carpenter  writes  as  follo\\ 


287 

"This genus  difieif  from  c<i//i*(»i,/<i.>-  in  having  the  eaves  nl. 

the  ttvth  straight  'th-Hi-h    i'iv.|nent  ly  |.n.|.prd    oiit.-id.',   a-  in    f 
».  the  mantle  en.udrd  with  minute  Imni; 
and    furnished  wit  1.  lichen    round  tin-    -utiir<-<. 

anterior  valves  is  5  slit,  M  in  Aruntli"i-i,;t,--,  hut  that  may  be  only  a 
specific  peculiarity.    The  7A///A//./  variabiKt  Ad.  and  Am'.  I'.  /..  9 
1-SI''I.   p.    1!M,    pn.hably  belongs  to  this  genus  hut    ha-  not  been 
dissected.    Angasia  is  known  at  once  from  Hanlwja  by  the  presence 

of  insertion  teeth  ;  and  from  /'/,/,-/'/, /io/v/  hythe  regular  articular i-.n 
of  the  tail  plate.  If  the  genera  be  grouped  according  to  the  raanth- 
poivs  Ant/'i*I'i  will  n-pn-sont  Chatto/,/*,!,-,/  in  the  tufted  series,  as 
Callistoplax  represents  (.'<tt/!*t»rlitton." 

A.   TETRICA   Carpenter,  n.  sp.     PI.  61,  figs  27-32  (sculpture  not 

represented.) 

Shell  oval,  greenish-ashen,  rather  elevated,  the  jugum  acute  ; 
mucro  slightly  in  front  of  the  middle,  slightly  elevated ;  valves 
squared,  beaked ;  the  terminal  ones  much  flattened.  Jugular  area 
obscurely  tricostate ;  lateral  areas  obscurely  defined  by  a  diagonal 
angle ;  anterior  valve  somewhat  obsoletely  five-angled ;  the  whole 
surface  very  closely  sculptured  with  wide,  irregular,  flattened  some- 
times striated  pebbles,  smaller  toward  the  dorsal  ridge. 

Interior:  Posterior  valve  having  9-13  slits,  the  teeth  small, 
radially  flattened,  rugose  outside  and  propped,  generally  bilobate  ; 
anterior  valve  having  5  slits,  the  teeth  more  acute,  roughened  out- 
side, slightly  propped  ;  central  valves  with  one  slit,  the  teeth  acute, 
rugose  outside,  conspicuously  thickened  or  propped  at  the  sides  of 
the  slit;  eaves  small;  sinus  narrow,  short,  smooth;  sutural  plates 
separated. 

Girdle  narrow,  leathery,  with  very  close  and  very  minute  cor- 
neous scales ;  at  the  sutures  and  around  the  end  valves  there  are 
bunches  composed  of  a  few  short  spicules,  and  there  are  a  few 
scattered  spicules  also. 

Length  15,  breadth  9$  mill.;  divergence  120°  (C 

Ceylon  (Mus.  Curaing,  No.  83). 

A.  tetrica  CPR.  MS:,  and  in  DALL,  Proc.  U.  S.  Nat  Mus.,  1881, 
p.  286  (no  description). 

A  common  observer  might  describe  the  mantle  .simply  as  rough 
and  leathery,  so  minute  are  its  remarkable  features.  T 


288  CALLISTOPLAX. 

structure,  l)ut  \vitliout  the  purrs,  characterizes  some  B  '-rein 

referred  to  r/m/i,y>/,-*//v<.      The  posterior  valve  somewhat  reseml>lrs 

an  irregular   M  '•/  :  the1  anterior  valve  is  strictly  Acanthochi- 

toid.     Both  of  tlu-se  an-  flatt<  m-d,  while  the  ridge  is  sharp  on  the 
.il  valves.  (Cpr.) 

Yar.  <  AI.CULOSA  Cpr. 

Shell  externally  very  similar  to  .  1  .  tetrica,  but  roseate  ;  jugal  areas 
distinctly  tricostate  ;  anterior  valve  distinctly  five-angled;  pebble- 
sculpture  smoother.  Interior:  posterior  valve  normal,  with  5  slits, 
t  la-  teeth  all  acute,  but  slightly  roughened,  hardly  propped;  sinus 
narrow,  deep,  smooth,  flat.  Bunches  of  spicules  minute,  inconspic- 
uous (Cpr.) 

J'/ti/ijijtitte*  (Mus.  Cuming  no.  79,  part.) 

An(/'i.«in  (/  tetrica  war.')  <-nl<-ul<>sa  CPR.,  MS. 

"  The  insertion  plates  of  this  shell  offer  a  marked  contrast  to  the 
Cingalese  shell,  being  strictly  like  Ischnochiton  (with  shortened 
eaves)  throughout.  But  one  specimen,  after  an  anterior  fracture, 
has  mended  it  with  distinctly  rugulose  teeth,  and  made  its  posterior 
teeth  propped  and  lobed,  showing  a  close  connexion  between  the 
tw<>  forms.  It  is  probable  that  Mr.  Cuming''s  specimens  from  the 
two  localities  had  been  intermixed.  The  tufts  could  scarcely  be 
detected  in  shriveled  specimens  "  (Cpr.} 

Genus  X  XVII.     CALLISTOPLAX  Carpenter,  1882. 


CPR.,  Table  of  Regular  Chitons,  1873.  —  Dall,  Proc. 
U.  S.  Nat.  Mus.  1881,  p.  283,  286  (Jan.  20,  1882).—  TRYOX,  Struct. 
and  Syst.  Conch,  ii,  p.  342. 

Valves  outwardly  and  within  as  in  Callistochiton.  Girdle  naked 
except  for  a  series  of  bristle-bearing  pores. 

The  present  genus  is  one  of  the  very  few  which  rest  entirely  upon 
characters  of  the  girdle  ;  but  so  different  is  this  from  that  of  Callis- 
tnchiion.  not  only  in  the  presence  of  pores,  but  in  the  entire  absence 
of  scales,  that  no  course  seems  open  but  to  treat  the  group  as  of 
generic  value. 

C.  RETUSUS  Sowerl>y.     PI.  fll,  figs.  17-26. 

Shell  small,  subeloniraU  ,  -lightly  elevated,  the  jugum  acute; 
mucro  median,  vory  obtuse,  elevated  in  adult  specimens.  Jugal 
area  smoothish,  granulose,  in  the  adult  having  a  few  acute  longitu- 


CAM  BTOPLAJL  '2*'.l 

dinal  linihe;   central  areas   with  about    ID   nigulo8e-gr:uio~e   lit 

each  side,  perpendicular  to  tin-  diagonal  line,  the  iut«-i--tic»-.-  »-IIH-»-|- 

lated.  Lateral  areas  havini;  two  very  strong  rounded  riln,  the 
front  one  stronger,  separated  by  a  narrow  sulc.us,  and  concentrically 
Wrinkle-graHOSe  and  very  minutely  ^ranulose;  sutures  \\ith  a  series 
of  imbricating  granules.  Anterior  valve  having  7  ribs,  of 
which  the  posterior  ones  (as  in  the  median  valves),  bifurcate,  and  are 
imbricated  along  the  sutures;  posterior  valve  in  the  young  shell 
having  (I  ribs,  all  of  these  bifurcate,  and  the  anterior  ones  split 
twice,  making  14  delicate,  flattened  ribs,  which  tend  forward  s 
what 

Interior:  the  posterior  valve,  in  a  young  specimen  has  about  11 
slits,  the  teeth  curved  in  harmony  with  the  external  ribs,  and 
directed  radially  outward  ;  in  the  adult  there  are  about  12  slits,  the 
teeth  solid,  directed  somewhat  forward,  rugose-costate  at  the  mar- 
gins, concave  in  the  middle,  the  eaves  very  heavily  callous.  Ante- 
rior valve  having  7-8  slits,  situated  in  the  middle  of  the  ribs,  the 
teeth  following  the  curvature  of  the  outer  margin,  acute.  Central 
valves  with  1  slit,  teeth  excurved,  eaves  wide,  pectinated,  spongy. 
Sinus  narrow,  deep,  narrowly  slit  on  each  side  of  the  lamina,  and 
sometimes  denticulated  by  the  external  sculpture. 

Girdle  narrow,  smooth,  thin,  having  40-53  bunches  of  long,  cor- 
neous hairs  around  the  margin,  hardly  sutural  (figs.  23,  24). 

Length  14*,  breadth  8  mill.;  divergence  120°. 

Guacomayo  and  Puerto  Portrero  (Cuming) ;  China  Seas  (Cum- 
ing.) 

Chiton  retmus  SOWB.  P.  Z.  8.  1832,  p.  28,  Conch.  Illustr.  f.  22.— 
REEVE,  Conch.  Icon.,  t.  17,  f.  W.—Plaxiphora  retusa  H.  &  A.  Ad. 
Genera  Rec.  Moll,  i,  p.  481. —  Callistoplax  retusa  CPR.  MS.  and  in 
Dall,  Proc.  U.  S.  Nat.  Mus.  1881,  p.  286. 

The  locality  "  China  Seas  "  given  by  Cuming  to  Carpenter,  is 
probably  wrong,  that  originally  given  by  Sowerby  being  much  more 
worthy  of  confidence.  The  above  description  is  from  Carpenter's 
MS. 

Figures  17-23  represent  a  young  specimen  ;  in  the  adult  the  ribs 
become  more  numerous  and  the  tail-plate  more  "  Acanthoid  "  in 
appearance  (figs.  25,  26). 


19 


290  CERATOZONA. 

Genus  X  X  VIII.    CERATOZONA  Dall,  1882. 

Ceratopltnrus  ('PR.,  Table  of  Regular  Chitons,  1873,  type  C. 
iiuililinyi  Rve.  Not  of  Diesing,  1850. —  Ceratozona  DALL,  Proc.U. 
8,  \;it.  Mus.  1881,  p.  283,  286  (Jan.  20,  1882).— Newcombia  CPR., 
V\.  type  C.setosus  Sowb.  Not  Neivcombia  Pfr.,  Malak.  Bl.  i,  p. 

117.  1854. 

Valves  strong,  exposed.  Insertion  plates  of  anterior  valve  long, 
sharp,  rugose  outside,  thickened  at  the  slits,  which  correspond  in 
position  to  the  external  ribs ;  median  valves  with  similar  propped 
teeth ;  tail  valve  having  the  teeth  thick,  shorter,  rugose,  sinus 
solid.  Girdle  tough,  bearing  peculiar  corneous  spines,  similar  in 
substance  to  itself,  generally  sparsely  bunched,  at  the  sutures.  The 
gills  extend  the  entire  length  of  the  foot.  Type  C.  guildingi  Reeve 
=  C.  rugosa  Sowb. 

Shuttleworth  may  readily  be  excused  for  grouping  the  type  of  this 
genus  in  Chcetopleura.  Compared  with  Ch.  hennahi  it  is  seen  that 
both  have  the  teeth  sharp,  and  rugose  outside ;  both  have  the  eaves 
solid  or  occasionally  with  a  row  of  minute  pores  along  the  outer 
bases  of  the  teeth ;  and  finally  both  have  horny  spinelets  on  the 
girdle.  But  in  Ceratozona  the  insertion  teeth  are  thickened  at  the 
slits  which  correspond  in  position  to  the  riblets  of  the  exterior  ;  the 
valves  are  much  more  firmly  held  in  the  tough  girdle,  and  the 
appendages  of  the  latter  are  much  more  deeply  inserted  in  its  sub- 
stance. If  we  examine  an  alcoholic  example  of  Chcetopleura 
h>  n/i'iJti  we  find  that  the  cuticle  of  the  girdle  peels  off  readily,  bringing 
with  it  all  the  spinelets,  which  leave  shallow  pits  in  the  fleshy  sub- 
stance of  the  girdle;  but  in  Ceratozona,  only  the  smaller  hairs  are 
thus  readily  removed,  the  larger  ones  being  deeply  and  very 
intimately  attached.  Moreover,  in  most  specimens,  a  pair,  or  a 
small  bunch  of  spines,  may  be  detected  near  each  of  the  sutures ; 
but  this  character  is  often  obscure  or  even  wholly  obsolete.  From 
Nuttallina  this  group  differs  in  the  solidity  of  the  sinus,  the  less  pos- 
terior mucro,  generally  rugose  and  "  propped "  teeth,  and  the 
peculiar  girdle-spines. 

C.  RUGOSA  Sowerby.    PI.  61,  figs.  33-37,  41-45. 

Shell  oblong,  rather  convex,  the  back  broadly  arched.  Surface 
generally  much  eroded,  green,  olive  or  slate-blackish  on  the  sides, 
the  central  areas  whitish  along  the  middle,  flamed  with  blackish  at 
the  sides,  or  green  there;  tail  valve  having  a  broad  pink  ray 
behind. 


291 

valves  are  strong,  and  when  not  eroded  they  are  somewhat 
'beaked.  Lateral  area-  hardly  raised,  but  defined  !,y  a  Strong 
rounded  rih,  sometime-  with  a  lower  wide  rib  behind;  having  a 
sculpture  of  irregular  wavy  wrinkles  over  ribs  and  interval,  and 
also  upon  the  >ides  of  the  cent  nil  area-.  Head-valve  having  about 
11  low  radiating  ribs  and  superlieially  waved  concentrically.  Tail 
valve  rather  depre^ed  with  a  siibcentral,  slightly  projecting  mucro, 
the  area  behind  it  obsoletely  radiated. 

Interior  blue-green,  varying  in  intensity.  Sutural  plates  moder- 
ate, separated  by  a  rather  wide  smooth  sinus.  Anterior  valve 
having  7-10  slits,  the  teeth  long,  acute,  slightly  rugose  outside  and 
denticulate  at  the  edge,  generally  thickened  or  propped  very  strongly 
along  the  slits  ;  central  valves  with  1  slit,  the  teeth  much  thickened 
at  the  edges  of  the  slit ;  posterior  valve  having  8-10  slits,  the  teeth 
much  shorter  and  blunter  than  in  front,  wedge-shaped,  denticulate 
at  the  edge,  not  perceptibly  propped  or  thickened  along  the  slits, 
Eaves  very  narrow,  having  a  single  series  of  pores  along  the  bases 
of  the  teeth. 

Girdle  very  tenacious,  rather  wide,  yellowish,  armed  with  numer- 
ous corneous,  yellow  rather  long  and  pointed  spines,  most  numerous 
around  the  edge,  and  in  most  specimens  showing  a  bunch  of  several 
at  each  suture ;  among  these  larger  spines,  slender  flexible  beards 
are  scattered  (fig.  35). 

Length  40,  breadth  25  mill. ;  generally  smaller. 

Jupiter  Inlet,  east  coast  of  Florida  (G.  TV.  Webster  et  a/.)  to 
Jamaica  (C.  B.  Ad.,  Johnson  &  Fox)  ;  Porto  Rico  (Blauner)  ;  St. 
Vincent  and  Trinidad  (Guilding). 

Chiton  rugosus  (Gray)  SOWERBY,  Conchol.  Illustr.  no.  6,  fig.  49, 
(1841  ?).— REEVE,  Conch.  Icon.,  t.  18,  f.  115  (April  1847).—  Chiton 
(Chcetopleura)  rugosa  Sowb,  SHUTTL.,  Bern.  Mittheil.  1853,  p.  78. — 
Chiton  squalidiis  C.  B.  Ad.,  Proc.  Bost.  Soc.  Nat.  Hist.,  ii,  p.  8, 
(Jan.  1845). —  Chiton  gulldlngii  REEVE,  Conch.  Icon.,  t.  21,  f.  138 
(May,  1847). —  Cera^hoi'us  guildingi  CPR. —  Ceratozona  guildingi 
BALL,  Catal.  Mar.  Moll.,  S.  E.  U.  S.  p.  172.—  Ch.  bicolor  (C.  B.  Ad.) 
GRAY,  P.  Z.  S.  1847,  p.  67. 

This  species  is  not  likely  to  be  confused  with  any  except  the  next. 
The  valves  are  rather  strong  and  blue-green  inside,  sometimes  very 
pale.  The  girdle  is  of  a  conspicuous  horny  yellow  color  when 
scrubbed  as  in  most  cabinet  specimens,  but  is  dull  and  dark  in  the 
natural  condition.  The  horny,  curved  bristles  are  both  fine  and 


292  CERATOZONA. 

coarse,  but  the  more  delicate  ones  are  easily  lost.  The  pore-bunches 
at  the  sutures  are  rarely  conspicuous,  and  often  cannot  be  made  out 
without  the  aid  of  a  lens  and  a  lively  imagination  ;  and  this  fact 
somewhat  impairs  their  value  as  a  generic  character.  Nearly  all  of 
the  adult  specimens  I  have  seen  are  very  much  eroded. 

Some  recent  authors  have  used  the  name  guildingi  Reeve,  for 
this  species ;  it  is  not  easy  to  see  why,  for  Sowerby  and  Adams  both 
preceded  the  author  of  the  Iconica.  The  original  figure  of  guildingi 
is  copied  on  my  plate,  fig.  37.  The  sculpture  varies  a  good  deal. 
Fig.  36  is  drawn  from  one  of  the  most  strongly  sculptured  speci- 
mens I  have  seen,  from  Jupiter  Inlet,  Fla.  Fig.  34  is  from  Sta. 
Cruz.,  of  the  Virgin  group,  being  drawn  from  a  specimen  colored 
exactly  like  Sowerby's  original  figure  of  rugosus  (fig.  33).  In  this 
shell  the  teeth  are  less  propped  and  the  eaves  narrower  than  in  the 
Florida  examples.  Fig.  35  is  from  a  Jamaica  specimen. 

I  have  seen  no  specimen  with  the  mucro  so  posterior  as  it  is  shown 
in  Carpenter's  figure  (fig.  41)  ;  all  I  have  seen  resemble  fig.  39. 

C.  SETOSA  Sowerby.    PI.  61,  figs.  40,  38,  39. 

Shell  oblong-oval,  ashy-greenish,  scabrous;  front  valve,  lateral 
areas  and  posterior  valve  radially  sulcate.  Marginal  ligament 
setose,  the  setae  rather  short  and  close. 

Length  32$,  breadth  15  mill.  (Sowb). 

Ouacomayoy  Central  America  (Cuming). 

Chiton  setosus  SOWB.,  P.  Z.  S.  1832,  p.  27 ;  Conch.  Illustr.  f.  19.— 
REEVE,  Conch.  Icon.,  f.  100.  Not  C.  setosus  Beechey's  Voy. 
'  Blossom '  t.  41.  f.  17,=Mopalia.  Not  Ch.  setosus  Tiles,  Mem.  Ac. 
S.  Pet.  ix,  p.  484(1824). 

This  species  is  very  distinct  from  C.  setiger  King,  which  it  in  some 
degree  resembles.  The  bristles  around  the  edge  are  much  shorter, 
thicker  and  more  closely  set.  (Sowb). 

Carpenter  has  had  figures  of  the  interior  and  tail  valve  prepared, 
and  I  have  copied  them  in  my  figs.  38,  39.  I  h#ve  seen  no  species 
of  this  sort  from  the  Pacific  side  of  the  isthmus,  and  I  am  therefore 
not  prepared  to  say  what  relation  setosa  sustains  toward  rugo*a,  the 
West  Indian  form.  Fig.  40  is  a  copy  of  Sowerby's  original  figure 
of  setosus. 


MOl'AMII)  I  .  293 

Family  MOI'AIJ  II>. K  I'ilsbry. 

(part  •  and  .1/oy^/o/',/, ,,  (part)  C'l 

Chitons  in  which  the  valves  are  divided  in  tin-  normal  manner 
into  lateral  and  central  areas;  the  teeth  of  insertion  are  not  pectina- 
ted ;  and  the  posterior  valve  has  a  posterior-median  sinus,  with  one 
slit  on  each  side  or  none.  The  girdle  is  more  or  less  hairy,  never 
scaly.  (Jill  row  as  long  as  the  foot. 

The  normal  number  of  slits  in  the  anterior  valve  is  8  ;  but  this  is 
often  increased  or  diminished  by  splitting  or  fusion  of  one  or  two 
teeth.  The  slits  correspond  in  position  to  external  ribs,  as  in  the 
last  subfamily.  In  certain  forms  (Placiphorella,  Placophoropsis) 
the  number  of  anterior  slits  is  abnormally  multiplied.  The  inter- 
mediate and  posterior  valves  have  not  more  than  1  well  developed 
slit  on  each  side,  and  even  this  is  lacking  in  the  tail  valve  of  Plaxi- 
phora. 

The  girdle  clings  more  tenaciously  to  the  teeth  than  in  most 
chitons,  being  like  that  of  Ceratozona.  It  is  frequently  provided 
with  pores  at  the  sutures,  each  pore  generally  bearing  two  or  several 
bristles  or  hairs  ;  but  the  presence  or  absence  of  these  pores  is  in  no 
case  of  more  than  specific  value,  and  in  some  cases  I  have  found  it  to 
be  a  mutable  feature  among  individuals  of  the  same  species. 

The  present  family  is  in  no  manner  identical  with  that  so  named 
by  Dall,  or  with  Carpenter's  division  of  similar  name  ;  nor  is  it  in 
any  sense  equal  to  the  Placophoridce  of  Dall,  Placiphoroidea  Cpr. 
These  Carpenterian  divisions  of  the  "  Irregular  Chitons  "  are  very 
artificial,  just  as  the  primary  division  of  the  group  into  "  Regular" 
and  "  Irregular  "  forms  is  artificial. 

The  ancestors  of  Mopaliidce  were  Callistoplacince,  probably  not 
very  different  from  the  recent  genus  Ceratozona. 

Key  to  the  genera  of  Mopaliidce. 

a.  Posterior  valve  having  a  slit  on  each  side  of  the  median  sinus. 
b.  Shell  oblong ;  girdle  narrower  in  front  than  at  the  sides, 
its  hairs  smooth  ;  teeth  of  insertion  not  lobed.       MOPALIA. 
bb.  Shell  rounded-oval ;  girdle  expanded  and  broadest  in  front, 
its  hairs  scaly  ;  teeth  of  insertion  more  or  less  lobed. 

PLACIPHORELLA. 
<za.  Posterior  valve  having  a  median  tail-sinus  but  no  slits. 

PLAXIPHORA. 


294  MOPALIA. 

Genus  X X I X.     MOPALIA  Gray,  1847. 

Mnjt,,lin  OKAY,  P.  Z.  S.  1847,  pp.  65,  69,  169,  (exclusive  of  sec- 
tion *  *).  Type  Ch.  hind*ii. — CARPENTER  MS.  and  in  Dall,  Proc. 
U.  S.  Nat.  Mus.,  1878,  p.  3Q3.—Molpalia  GRAY,  Guide  Syst.  Dist. 
Moll.  B.  M.,  p.  184  (err.typ.),  1857.— GOULD,  Otia,  p.  118.— 
0*teoclriton  DALL,  Proc.  U.  S.  Nat.  Mus.  1886,  p.  211.  Type  M. 
sin  uata  Cpr. 

Valves  normally  proportioned,  transverse,  not  beaked,  exposed, 
the  girdle  somewhat  encroaching  at  the  sutures.  Sinus  small ;  inser- 
tion-plate of  anterior  valve  rather  long,  sharp,  slit  into  nearly 
smooth  teeth  which  are  somewhat  thickened  at  the  edges  of  the  slits, 
the  latter  being  normally  8  in  number  and  corresponding  in  position 
to  external  ribs.  Median  valves  having  similar  1-slit  insertion- 
plates.  Posterior  valve  depressed,  the  mucro  post-median,  insertion 
plate  rather  sharp,  smooth  or  roughened,  having  an  oblique  slit  on 
each  side  (rarely  doubled)  and  a  larger  sinus  in  the  middle  behind. 
Girdle  wider  at  the  sides  than  in  front,  leathery,  more  or  less  hairy,, 
the  hairs  simple  ;  with  or  without  sutural  pores. 

This  genus  is  known  only  from  the  shores  of  the  northern  Pacific, 
extending  from  Lower  California  to  Alaska  and  Japan.  It  may  be 
regarded  as  the  most  primitive  of  the  existing  genera  of  Mopaliidce ; 
Placiphorella,  and  Plaxiphora  being  special  modifications  of  the 
Mnfuilia  type.  The  small  additional  slits  occurring  in  some  forms, 
such  as  M.  acuta,  are  cases  of  partial  reversion  to  the  multifissate 
ancestral  form  which  gave  rise  to  the  family. 

Two  species  of  Mopalia  were  placed  by  Carpenter  in  Placiphorella 
on  account  of  their  possessing  sutural  pores.  Dall  justly  remarks 
that  they  differ  from  the  true  Placiphorellas,  and  he  proposes  Osteo- 
chiton  as  a  section  of  that  group  for  their  reception.  It  is  my  belief 
that  these  species  have  no  near  alliance  with  Placiphorella,  but  that 
they  are  merely  modified  Mopalise.  The  gathering  of  a  few  hairs  or 
spicules  into  a  pore  at  the  sutures  is  no  uncommon  occurrence,  and 
in  some  cases  (such  as  Ceratozona)  it  is  not  constant  even  as  a  speci- 
fic character.  In  Mopalia  this  modification  will  probably  be  found 
to  occur  in  all  the  forms  in  which  the  girdle  is  nearly  naked.  In  a 
small  form  of  M.  muscosa  from  Bolinas  Bay  the  pores  are  sometimes 
present  at  all  of  the  sutures,  and  sometimes  at  only  two  or  three  on 
one  side,  entirely  absent  on  the  other  side.  Sometimes  they  bear 
each  a  large  hair,  sometimes  none.  It  is  therefore  obvious  that  we 
can  make  no  disposition  of  Osteochiton  except  to  consider  it  an 
absolute  synonym  <•!'  M»},<dia. 


'2'.  ft 

M.  MU8C08A  Gould.     ri.i;.1!,  ftgi,  I'1.  "al),fig».  49-63  (varr). 

Shell  oval,  elevated  <>r  <l.-|.r«-.- ed,  tin-  d<T-al  rid-i-  UPTC  OF  \9U 
an-nlar.  Valves  strong.  Sin-tare  lotterlcM,  lim-ly  .-rulptiin-d  with 
wavy,  nvuulatrd  lo^itudiiial  rildeK  .,1't. n  OWN  01  let*  obsolete. 
Color  ireuerally  dull  hn.wn,  Idaekish-olive  or  grayish,  1-  times 

bright  orange,  scarlet  or  vivid  green. 

Mrdian  valves  hardly  braked,  the  lateral  areas  slightly  raised, 
irranose,  limited  by  a  raised  granose  riblet.  Central  areas  having 
close  fine  longitudinal  riblets,  with  rrenulated  or  latticed  int»-i>tices, 
the  riblets  finer  and  converging  on  the  ridge  of  the  last  6  valves, 
diverging  on  the  second  valve,  or  strongly  diverging  on  the  ridge  of 
all  valves,  like  a  series  of  superimposed  v's.  Anterior  valves  having 
about  10  narrow  radiating  granose  riblets,  the  intervals  granose. 
Tail  valve  depressed  with  posterior  mucro,  the  posterior  slope  very 
short,  emarginate  behind. 

Interior  bluish-green,  stained  with  lilac  on  the  central  callus. 
Anterior  valve  having  8,  median  1  short  slit,  the  teeth  long,  deeply 
striated  outside  and  thickened  or  propped  outside  at  the  sides  of  the 
slits.  Posterior  valve  having  a  rounded  sinus  behind,  with  one 
oblique  slit  on  each  side,  the  plate  roughened  outside  near  the  slits. 
Sutural  plates  broad,  the  sinus  extremely  shallow  and  small. 

Girdle  rather  narrow,  densely  covered  with  round,  curved  or 
curled  hairs.  Gill  row  as  long  as  the  foot  (pi.  64,  fig.  74). 

Length  52,  breadth  38  mill. 

Length  25-60,  breadth  15-40  mill. ;  divergence  120°-140°. 

Shumagin  Is.  (rare)  to  San  Diego,  California,  between  tide  marks 
and  at  lowest  water. 

Ch.  muscoms  GLD.,  Proc.  Bost.  Soc.  N.  H.  ii,  p.  145,  July,  1846 ; 
Exped.  Moll.,  p.  313,  f.  436  ;  Otia,  p.  6.—  Chiton  dliatus  REEVE 
Conch.  Icon.,  t.  19,  f.  124. — Mopalia  ciliata  H.  &  A.  AD.  Gen.  Rec. 
Moll.,  i,  p.  478.— DALL,  Proc.  U.  S.  Nat.  Mus.,  1878,  p.  303  (syn- 
onymy and  variation)  ;  p.  298,  f.  35,  35a  (dentition).  NOT  Ch. 
ciliatus  Sowerby  ! —  Chiton  setosus  Sows,  in  Beechey's  Voy.  '  Blos- 
som' p.  150,  t.  41,  f.  17  (not  C.  setotus  Sowb.  1832).—  Ch.  collei 
REEVE,  Conch.  Icon.,  t.  21,  f.  136  (1847). —  Ch.  wosnessen*kii 
MIDD.  Mai.  Ross,  i,  p.  101  (part  of  diagnosis). —  Chiton  nnnatua 
NUTT.,  JAY'S  Catalogue,  1839,  no.  2678  (not  described)  ;  Ch.  aren- 
atus  NUTT.,  in  Mus.  Acad.  Nat.  Sci.  Philadelphia. —  C.  ornatus 
NUTT.  MS.  CPR.,  P.  Z.  S.  1855,  p.  232.— and  C.  consimilis  NUTTALL, 
MS.  in  Brit.  Mus. 


296  MOPALIA. 

Iii  its  typical  state  (pi.  63,  fig.  46),  this  species  may  lu-  known  by 
the  stroug  though  variable  sculpture,  dull  brown  or  blackish-olive 
color,  the  small  sinus,  the  girdle  being  thickly  set  with  round  hairs 
varying  from  strong  bristles  to  soft  hairs.  A  variation  in  color  is 
seen  in  some  southern  specimens  (Tomales  Bay)  which  are  orange 
or  scarlet  (pi.  63,  fig.  48),  or  yellowish  maculated  with  orange  and 
vermilion.  Others  from  the  same  locality  are  vivid  blue-green  or 
green  (pi.  63,  fig.  47). 

In  his  work  on  the  Chitons  of  Alaska,  Dr.  W.  H.  Dall  discusses 
the  synonymy  and  variation  of  this  species,  concluding  that  M. 
lignosa  Gld.  should  be  regarded  as  an  extreme  form,  connected  by 
intermediate  examples  with  the  typical  muscosa.  He  writes  as  fol- 
lows: "This  species  can  be  distinguished  from  all  varieties  of 
wossnessenskli  by  its  blackish  and  proportionately  much  narrower 
girdle,  and  by  a  sort  of  prolongation  of  the  external  layer  of  the 
shell  forward  under  the  apex  of  the  next  anterior  valve  in  the 
median  line,  forming  a  sort  of  anterior  false  apex,  which  is  hidden 
until  the  valves  are  separated.  In  wossne*«enskli  this  part  is 
squared  off,  the  girdle  is  yellowish  (when  alive),  and  the  valves  are 
much  less  transverse.  It  will  be  surprising  if  those  who  have  only 
observed  these  animals  by  a  few  dry  specimens  in  collections  are 
willing  to  accept  the  synonymy  above  given,  I  confess  that  not  long 
since  I  would  have  been  unwilling  to  believe  that  the  rough,  bristly, 
typical  muscosa  and  the  dark,  smooth  hindsii  could  be  properly  com- 
bined under  one  name  with  each  other  or  with  the  finely  reticulated 
and  painted  lignosa ;  but  the  study  of  a  large  multitude  of  speci- 
mens has  convinced  me  no  arbitrary  line  can  be  drawn  anywhere  in 
a  fully  representative  series,  beginning  with  coarsest  ciliata  [muscosa] 
and  ending  with  a  practically  smooth  hind*ii.  The  characters  of 
girdle,  sculpture  and  form  are  not  only  variable  in  themselves,  but 
are  found  variably  combined,  except  that  it  is  rarer  to  find  coarsest 
sculpture  with  a  downy  than  with  a  bristly  girdle.  However,  even 
this  occurs.  On  the  other  hand,  out  of  such  a  series  a  dozen  forms 
might  be  selected  which,  if  only  the  characters  were  constant,  every 
one  would  acknowledge  as  good  species.  " 

Var.  HINDSII  (Sowb.)  Reeve.     PI.  62,  figs.  99,  100;  pi.  63,  fig. 
57. 

Shell  elongated  and  much  depressed,  (the  angle  of  divergence 
about  140°),  the  girdle  encroaching  at  the  suture*.  External  color 
a  light  or  dark  shade  of  olive.  Surface  smoother  than  in  typical 


Morxi.i  A. 

the  grtfiote-oorrugation  b  or  lenzig-xagorcriit- 

oi»  tin-  central    arras,  «il»li«jm-ly   r..migated-grano8e  on   the 

lateral    aivas.      /nt<ri<>r    \rhil>\    "•/'//,    «/<or<  cr/' 

;   tail  -inn-  visiMr  outside.       (iinll.-  with  fi-w  and  .-hurt   I. 


hinil.<ii  .  Si,\vl».  in  Mus.  Cuming)   lii  ndi.  I«-.,n.,  t. 

11'.  f.  117.1,  b  (1847).—  Mopnlin   /ihul.«n  (  i  KA  Y,  I'.   /.  S.  1M7,  pi 
169.—  II.  it  A.  AD.,  Genera  Rec.  Moll,  i,  p.  478,  iii,  t.  54,  f.  7.— 
MnjHtlia  ritinta  rur.  Itindsii  DALL,  Proc.  U.S.  Nat.  Mus.  187> 
304. 

The  specimens  described  are  from  San  Francisco  Bay.  The  teg- 
mentum  or  outer  layer  of  the  valves  projects  forward  somewhat  at 
the  sinus,  as  in  typical  nmscosa^  but  this  can  be  seen  only  in  the 
detached  valves. 

Var.  PORIFERA  Pilsbry.     PI.  62,  figs.  93,  94. 

Another  form  of  muscosa,  which  if  constant  in  its  peculiar  features 
would  make  an  excellent  new  species  of  the  section  0«teochiton,  is 
before  me  from  Boliuas  Bay.  It  is  perhaps  deserving  of  a  varietal 
name.  The  shell  is  rather  small,  thin  and  high,  but  not  to  as  great 
an  extent  as  M.  acuta.  It  is  sculptured  as  in  M.  hindsii,  but  the 
diagonal  and  sutural  ribs  are  more  prominent,  and  sculptured  with 
strong,  transverse  beads  exactly  as  in  M.  imporcata,  the  suture  being 
dentated  by  them.  Color  of  valves  olivaceous,  clouded  obscurely 
with  smoky,  and  having  a  black  stripe  each  side  of  the  dorsal 
lighter  stripe.  The  posterior  valve  has  a  depressed  mucro  near  the 
posterior  margin,  which  is  very  slightly  waved  inward.  Girdle 
firm  and  leathery,  minutely  and  evenly  papillose  all  over,  blackish 
with  spots  of  orange  ;  having  a  small  pit  or  pore  at  each  suture,  with 
a  series  of  pores  alternating  with  these  a  little  outside  of  the  middle 
of  the  girdle  (pi.  62,  fig.  93).  Sometimes  some  of  the  sutural  pores 
bear  large  hairs,  curling  outward;  and  sometimes  some  or  many  of 
the  pores  are  completely  absent. 

Length  23,  breadth  13*  mill.;  divergence  105-115°. 

The  interior  is  a  deep  blue-green,  or  gray-blue  \vith  a  purple-pink 
blush. 

Var.  ACUTA  Carpenter.     PL  64,  figs.  75-81. 

Shell  rather  small,  strongly  elevated,  the  dorsal  ridge  acute  : 
valves  thin  ;  sculpture  minute  and  delicate,  varying  between  a 
minute  granulation  and  a  fine  pitting;  the  sutures  delicately  dentic- 


298  MOPALIA. 

ulate ;  diagonal  riblets  obsolete  or  delicately  raised.  Color  oliva- 
ceous obscurely  mottled  with  dusky,  the  tail  valve  having  a  light 
ray  behind. 

Interior  blue-green.  Tail  valve  slightly  waved  upward  in  the 
middle  behind,  and  having  either  a  simple  narrow  caudal  slit,  or  a 
slit  with  a  small  tooth  set  in  its  apex.  Lateral  slits  of  the  tail  valve 
generally  double  on  one  side.  Girdle  narrow,  sparsely  hairy. 

Length  22*,  breadth  12$  mill.;  divergence  105°  (Carpenter's 
type). 

Length  22,  breadth  13  mill. ;  divergence  105°  (San  Diego  spec.). 

Length  23,  breadth  15  mill.;  divergence  98°  (Sta.  Barbara 
spec). 

Santa  Barbara  (Canfield,  Gabb.)  ;  San  Diego  (Hemphill). 

Chiton  acutusCpn.,  P.  Z.  S.  1855,  p.  232.— Mopalia  acuta  CPR., 
Brit.  Asso.  Rep.  1863,  p.  648. — Mopalia  plumosa  and  M.  (f  var.) 
fissaCpR.,  MS.  (?  Not  Ch.plumosus  Gld). 

The  comparative  tenuity  of  the  highly  angled  valves,  their  deli- 
cate sculpturing  over  the  whole  surface,  the  fine  denticulation  of  the 
sutures  and  the  narrow,  often  toothed  caudal  sinus,  all  give  an 
aspect  of  individuality  to  this  form,  and  cause  me  to  rank  it  with 
hind*ii  and  lignosa  as  a  well-differentiated  subspecies. 

Carpenter,  working  from  very  few  specimens,  made  three  species 
of  the  forms  of  this.  The  occasional  bi-slitting  of  the  tail  plate  on 
one  side  is  found  also  in  some  specimens  of  the  elevated  variety  of 
lignosa  from  Olympia,  Wash.  It  seems  to  me  to  be  a  very  variable 
and  trifling  character.  The  caudal  sinus  seems  to  be  indifferently 
narrowly  slit  or  with  a  little  denticle  in  the  apex  of  the  slit,  and  this 
little  denticle  also  occurs  sometimes  in  M.  lignosa.  The  posterior 
valve  has  a  narrow  light  triangle  behind  in  all  the  specimens  I  have 
seen. 

I  have  no  hesitation  in  pronouncing  plumosa  and  fissa  absolute 
synonyms  of  acuta,  but  give  here  Carpenter's  descriptions. 

M.  plumosa.  Carpenter.  (PI.  64,  figs.  80,  81.)  Shell  oval,  regu- 
lar, thin,  elevated,  the  dorsal  ridge  acute,  mucro  behind  the  middle, 
depressed.  Valves  subquadrate,  slightly  beaked  behind,  hardly  so 
in  front.  Olivaceous-ashen  maculated  with  darker;  central  areas 
(with  the  scarcely  defined  jugal  tracts)  reticulated-porous,  being 
sculptured  with  interlacing  riblets  forming  quincuncially  arranged 
impressed  pits.  Lateral  areas  defined  but  hardly  elevated,  sculp- 


MOPAMA. 

turnl  with  plumr-likr  radii,  granose  at  the  SUtun -,  t  h.-  «ii;iLr"iial  ribs 

and  tin-   radiating  rililrts  of  the  head-valve ;  the  grains  elongated, 
siihspinose,  elegantly  strrntimj  (fie  sutures. 

Interior  pule  blue.  Tail  valve  having  the  p«.~t< Ti-.r  linoi  hardly 
indicated  externally,  xinof/,  »/•/'//»  <t  minute  toof/i  00J  ///  nf  //«:  apex; 
at  one  title  it  fut*  "2,  <it  ike  other  3  slits;  slit-rays  Inconspicuous. 
Central  valves  having  1,  anterior  valve  8  slits,  the  slit-rays  con- 
spicuous; teeth  acute,  small.  Eaves  small,  very  spongy.  Sinua 
s-iuall,  deep,  flat,  the  sutural  plates  separated. 

Girdle  thin,  narrow,  smooth,  sparsely  and  irregularly  beset  with 
subtranslucent,  larger  and  smaller  tubular  bristles. 

Length  16i,  width  11  mill. ;  divergence  112°. 

Habitat  unknown. 

The  above  description,  from  Carpenter's  MS.,  was  drawn  from  a 
single  specimen  in  the  collection  of  Dr.  Wesley  Newcomb  (now  of 
Cornell  College).  The  figures  80,  81  represent  the  same  specimen. 

V&r.fissa  Cpr.  Sculpture  between  that  of  M.  acuta  and  M.  pin- 
mosa ;  the  granules  at  the  suture  and  diagonal  rib  hardly  claw- 
shaped;  color  and  form  also  intermediate.  Interior:  posterior 
valve  having  two  slits  on  one  side,  one  on  the  other,  the  median 
caudal  sinus  minute,  acutely  slit ;  otherwise  normal.  Girdle  smooth 
with  sparse,  small  spines. 

Length  15,  breath  10  mill. ;  divergence  115°. 

This  form  was  described  by  Carpenter  from  a  single  specimen 
from  Monterey.  It  differs  from  acuta  and  plumosa  in  lacking  the 
"key-stone"  like  structure  of  the  caudal  sinus;  but  the  series 
examined  by  me  proves  that  this  character  has  no  constancy. 

Subspecies  M.  LIGNOSA  Gould.    PL  63,  figs.  58,  59  (typical) ;  60, 
61,  62,  63. 

Shell  oval,  elevated,  carinated  or  angular  at  the  dorsal  ridge,  the 
side-slopes  straight.  Surface  lusterless,  apparently  smooth  ;  grayish, 
greenish  or  bluish  with  radiating  streaks,  lines  and  flammules  of 
brown  or  purple-brown. 

Under  a  lens  the  lateral  areas  appear  nearly  smooth  ;  the  central 
areas  being  closely  and  finely  pitted  all  over.  Girdle  narrow, 
sparsely  hairy. 

Interior  white  and  light  blue.  Length  60,  breadth  35  mill. ; 
divergence  120°. 

Vancouver  I.  to  Monterey,  California. 


300  MOP  A  LI  A. 

Chiton  lignosus  OLD.,  Proc.  Boston  Soc.  N.  H.  ii,  p.  142,  (July, 
1846) ;  Otia  Conch,  p.  3 ;  U.  S.  Expl.  Exped.,  p.  330,  f.  424.— 
•nplmrn  li'jnosa  GLD.,  Otia,  p.  248. — Mojxilin  lignosa  CPR., 
Rep.  Br.  Asso.  1863,  p.  648.—  Chiton  merckii  MIDD.,  Bull.  Imp. 
Acad.  Sci.  St.  Petersb.  vi,  p.  20,  1846  ;  Mai.  Ross.,  i,  p.  115,  1. 11,  f. 
5-6.—  Ch.  eschscholf:li  MIDD.,  Bull.  1.  c.  p.  118,  Mai.  Ross.,  i,  p.  114, 
t.  11,  f.  4  (young  shell). —  Chiton  mo/if<  reyensi*  CPR.,  P.  Z.  S.  1855, 
p.  231.—  Chiton  ve*pertinu*  GLD.,  U.  S.  Expl.  Exped.  Moll.  p.  323, 
t.  426,  426a  (1852).—  Chcetopleura  respertina  GLD.,  Otia,  p.  230, 
'l-\°l.—Mnpitl{«  vespertina  H.  &  A.  AD.,  Gen.  Rec.  Moll,  i,  p.  479.— 
Mopalia  rimptoni  GRAY,  P.  Z.  S.  1847,  p.  69  ;  H.  &  A.  AD.,  Gen. 
p.  479;  and  Brit.  Mus.  Coll.  (name  only;  never  described.  Type 
examined  by  Cpr). — Mopalia  ciliata  *•!</>.</>.  lignosa  Gld.,  DALL, 
Proc.  U.  S.  Nat.  Mus.  1878,  p.  304. 

Typically  the  M.  lignosa  is  extremely  unlike  M.  muscosa,  but  I  am 
compelled  to  agree  with  Dall  that  there  exist  specimens  completely 
uniting  the  two.  A  number  of  published  names  are  above  added  to 
the  long  list  of  synonyms  given  by  Dall  (1.  c.)  ;  and  Ch.  californicus 
(Nutt.)  Reeve,  which  Dall  includes,  is  removed,  as  it  belongs  to  the 
genus  Nuttallina. 

The  typical  lignosa  (figs.  58,  59)  is  exactly  equal  to  merckii,  to 
montereyensi*,  and  to  the  unpublished  insigni*  Newc.  (fig.  63).  It 
differs  from  the  following  form  in  the  even  puncturing  of  the  sur- 
face (obsolete  on  lateral  areas),  the  peculiar  painting,  and  white 
interior. 

The  principal  mutations  of  this  type  of  Mopalia  are  (1).  Toward 
still  smoother  forms  entirely  lacking  pitted  or  reticulated  sculpture, 
having  only  a  few  subobsolete  longitudinal  wrinkles  on  the  ridge, 
the  painting  in  concentric  streaks  (following  growth  marks)  on  each 
valve.  This  is  shown  in  figs.  60,  61,  of  pi.  63,  the  specimen  illus- 
trated being  from  Olympia,  Washington.  The  C.  vespertinti*  of 
Gould  is  closely  connected  with  this  form,  but  is  represented  as 
typically  much  pitted  (fig.  62).  It  is  stained  with  crimson  within. 

(2).  Form  elevata  (pi.  64,  figs.  82,  83).  More  elevated,  acutely 
carinated,  more  or  less  pitted  superficially,  and  either  painted  with 
the  pattern  of  typical  lignox  on  a  white,  creamy  or  green  ground, 
or  having  concentric  zig-zag  blackish  streaks  (fig.  82).  Divergence 
about  90°.  The  interior  is  bright  green  or  blue. 

(3).  Forms  connecting  with  M.  muscosa  var.  hi/i<l*ii,  having  the 
color  pattern  of  //</ //••*./.  but  the  sculpture  intermediate  in  char- 


•  I-  \l  I  \. 

acter  or  quite  like  thai  of  /////•'' 
M.  MIM.I  MM>K!  i  ii  Sehraick,     I'l.  ^2,  figs.  88,89,  90,91,92. 

Shell  elevated.     Coloration:   a  broad  whitish  area  along  the  mid- 
dle, with  transverse  flainniules  and    lines  «»!'  mi-brown  "ii  tin-  rl 
at    th.'   lidei   concentrically   and    longitudinally    painted    \\ith    r»-d- 
brown  and  whitish. 

Median  valves  having  the  apex  indistinct,  the  lateral  JWM-  «li- 
tinet.  Kntire  surface  radially  closely  pitted,  the  pits  very  di.-tim-t 
over'the  whole  of  the  central  areas,  and  in  the  middle  of  the  lateral 
areas,  but  obsolete  on  the  front  and  back  edges  of  the  latter. 
Anterior  valve  having  8  radiating  riblets.  Posterior  valve  slightly 
emarginate  behind. 

Interior  roseate  in  the  middle  ;  lateral  slits  distinct ;  sinus  shal- 
low. Anterior  valve  having  8,  central  1,  posterior  two  slits. 

Girdle  of  moderate  width,  brown-red,  setose,  the  setse  irregularly 
and  sparsely  scattered,  whitish,  and  about  3  mill,  in  length. 
Branchiae  median,  with  about  36  branchial  lamellae. 

Length  14  mill. ;  divergence  about  115°. 

Bay  of  Castries  in  25  ft. 

Chiton  middendorffii  SCHRENCK,  Bull,  de  1'Acad.  des  Sci.  St. 
Petersb.  iv,  p.  408 ;  Mel.  Biol.  iv,  p.  89 ;  Reisen  und  Forsch.  in 
Amur-Lande,  ii,  Zool.,  p.  278,  t.  12,  f.  1-8  (1867). 

A  single  specimen  of  this  species  was  dredged  by  Schrenck,  from 
whose  account  the  above  description  is  compiled.  The  sculpture 
strongly  reminds  one  of  some  forms  of  Mopalia  lignosa  Gld.,  but  the 
coloring  differs  markedly,  and  the  habitats  of  the  two  are  widely 
sundered. 

M.  IMPORCATA  Carpenter.     PL  62,  fig.  98. 

Shell  small,  oblong,  strongly  elevated  and  acutely  carinated,  the 
side-slopes  straight.  Buff-white,  slightly  stained  ivith  rust-brown. 

The  median  valves  are  acute  at  the  umbo,  but  there  is  no  project- 
ing beak ;  lateral  areas  bounded  by  a  strongly  elevated,  narrow, 
crennltted  diagonal  rib,  and  having  a  wider  rib  at  the  sutural  mar- 
gin, also  crenulated,  thus  denticulating  the  suture ;  the  space 
between  the  two  lateral  ribs  being  finely  corrugated-granose.  Cen- 
tral areas  sculptured  with  strong,  curved  longitudinal  ribs,  which 
converge  forward  somewhat,  toward  the  median  keel  ;  the  intervals 
between  these  ribs  being  closely  and  finely  latticed  across  by 


MOPALIA. 

threads  radiating  from  the  beaks.     Anterior  valve  having  8  strong, 
nan  .1   ribs,    with    one  wider  rib   at   each    sutural   edge. 

Posterior  valve  depressed,  the  mucro  situated  at  the  posterior  end. 

Interior  white;  sinus  very  small  and  shallow.  Anterior  valve 
having  8,  median  1  slit;  teeth  but  little  thickened  along  the  slits. 
Posterior  valve  having  a  rather  wide  moderately  deep  rounded  tail 
sinu>.  and  a  single  slit  on  each  side. 

Girdle  leathery,  dusty,  with  a  hair-pore  at  each  suture,  and 
some  scattered  or  alternating  hairs. 

Length  10,  breadth  6  mill.  ;  divergence  95°. 

J'lic/et  Sound  (Kennerley)  ;  Sta.  Barbara  (Cooper). 


imporcata  CPR.,  Proc.  Acad.  Nat.  Sci.  Phila.,  1865,  p. 
59.  —  Placiphorella  imporcata  CPR.,  in  Dall,  Proc.  U.  S.  Nat.  Mus. 
1878,  p.  306.—  Osteochiton  imporcatus  DALL,  1.  c.  1886,  p.  211. 

This  species  closely  resembles  M.  sinuata  in  size  and  sculpture. 
The  two  species  differ  in  the  following  details  :  (a)  M.  imporcata  is 
unicolored,  while  the  other  is  elegantly  marbled  with  blue  and 
tawny;  (6)  imporcata  has  the  sutural  ribs  more  developed  and  very 
distinctly  serrated,  whilst  in  sinuata  the  serration  is  hardly  appar- 
ent ;  (c)  imporcata  has  the  longitudinal  riblets  of  the  central  areas 
larger  and  the  radiating  threads  which  lattice  their  interstices  much 
smaller  and  much  closer  ;  and  finally,  (d)  the  tail  valve  in  imporcata 
has  an  entirely  posterior  mucro,  and  a  much  shallower  posterior 
sinus. 

The  girdles  are  the  same  in  both  species,  being  leathery,  generally 
"  dusty  "  in  appearance  in  dried  specimens,  although  scales  are 
quite  absent. 

Thi>  species  might  be  considered  a  subspecies  of  M.  muscosa  were 
it  not  that  it  is  smaller  and  more  highly  angled,  of  a  uniform  light 
color,  and  has  the  mucro  farther  to  the  rear.  The  girdle-pores  at 
the  sutures,  and  the  entire  sculpture  are  exactly  like  the  pore-bear- 
ing variety  of  muscosa  which  I  have  above  described  from  Bolinas 
Bay.  It  is  very  likely  that  the  intervening  links  required  to  com- 
plete this  chain  of  forms  will  he  found. 

The  description  and  figures  are  drawn  from  Carpenter's  type 
specimen,  now  in  the  U.  S.  National  Museum. 

The  length  is  estimated  in  this  and  the  following  species,  as  the 
specimens  are  somewhat  curled. 


MO  r  A  i.i  A. 

M.  BIKUA1  \  Carpenter.      IM.  i\'2,  BgS.  95,  '."'•,  97. 

Shell  oblong,  elevated  Mini  -tn.iiLrlv  rannat--.!,  the  .-id,—  . 
Straight.  Color  whitish,  rfnmh-il  //•////  fl,-/fc,i(r  liliir.-yrr'  n  iiml  , 
lated  ii'ith  rich  ///»/•////  />/•»•//•//. 

Median  vulvos  hardly  braked,  the  lateral  areas  not  raised,  but 
strongly  defined  by  an  elevated  diagonal  rib;  sculptured  with  two 
oblique  series  of  fine  riblets  forming  a  latticed  pattern.  Central 
areas  having  a  series  of  longitudinal  curved  rihlet.s  eonveri:in'_r 
toward  the  median  keel,  crossed  by  curved  radiating  threads  a 
little  finer  and  less  prominent  (fig.  97).  Anterior  valve  having  8 
(not  counting  the  posterior  sutural  borders)  strong  radiating  ril is 
narrower  than  the  latticed  intervals.  Posterior  valve  depressed,  the 
•macro  bcintj  at  the  posterior  third. 

Interior  bluish-white.     Sinus  very  small  and  narrow.     Anterior 

valve  having  8  slits,  median  1  slit ;  teeth  thickened  outside  at  the 

edges  of  the  slits.     Posterior  valve  (fig.  96)  having  a  deep  rounded 

infilinn  shins  behind   (which  is  continued  upward  in  a  superficial 

ition  to  the  mucro),  and  a  single  slit  on  each  side. 

Girdle  rather  narrow,  leathery,  "  dusty  "  bearing  a  few  hairs,  with 
a  rounded  pore  at  each  suture  (fig.  95). 

Length  11*,  breadth  7  mill.;  divergence  105°. 

Puget  Sound  (Keunerley)  ;  San  Francisco  Bay  (Newcomb). 

f  Mopalia  sinuata  CPR.,  Proc.  Acad.  Nat.  Sci.  Phila.,  1865,  p.  59. 
— Placiphorella  sinuata  CPR.,  MS.  and  in  DALL,  Proc.  U.  S.  Nat. 
Mus.  1878,  p.  303,  306—Osteochiton  sinuatus  DALL,  I  c.  1886,  p. 
211. 

This  little  species  has  the  form  and  sculpture  of  the  true  Mopalias, 
but  it  differs  from  them  in  the  posssesion  of  a  bristle  or  hair-bearing 
pore  at  each  of  the  sutures,  the  girdle  elsewhere  bearing  sparsely 
scattered  hairs  on  the  leathery,  minutely  roughened  surface.  It 
resembles  M.  imporcata  but  is  sufficiently  different  in  sculpture. 

My  description  and  figures  are  from  Carpenter's  type  specimen, 
now  in  the  Smithsonian  collection. 

M.  CILIATA  Sowerby.     PI.  64,  figs.  64-73. 

Shell  oblong,  rather  depressed,  the  dorsal  ridge  carinated  (some- 
times rounded),  side-slopes  straight  or  somewhat  convex.  Surface 
lusterless,  finely  sculptured,  variously  colored,  usually  either  (1, 
typical  coloring)  verdigris  green  maculated  with  black  or  black- 
brown,  the  girdle  yellow  (fig.  65)  or  (2)  maculated  with  maroon 
and  sometimes  touched  with  rich  chestnut  on  the  ridge,  or  having 


304  MOPALIA. 

some  valves  or  parts  of  valves  vivid  scarlet  (fig.  64),  or  scarlet 
mixed  With  olive  and  snow-white,  or  entirely  white;  or  (3)  light 
olive-buff  with  brownish  girdle  (fig.  67). 

Valves  somewhat  beaked,  the  lateral  areas  bounded  by  a  riblet, 
rather  coarsely  granulated,  with  larger  granules  along  the  posterior 
margin.  Central  areas  sculptured  with  longitudinal,  curving  rib- 
lets  somewhat  granulated,  much  closer  and  finer  on  the  dorsal 
ridge.  Anterior  valve  having  granose  narrow  radii,  the  intervals 
granulated.  Posterior  valve  small,  with  posterior  mucro,  broadly 
emarginate  or  waved  at  the  hinder  margin. 

Interior  bluish-white  or  light  blue-green.  Sinus  broad  and  rather 
rounded,  -^pongy  or  roughened.  Sutural  plates  arcuate.  Anterior 
valve  having  8  slits,  median  valves  1  slit.  Posterior  valve  having  a 
broad  deep,  rounded  caudal  sinus,  and  a  single  slit  on  each  side. 

Girdle  wide,  yellow  or  brown,  generally  notched  behind,  more  or 
less  sparsely  clothed  with  curling  strap-like  brown  /m  //•>-,  which  bear  near 
their  bases  a  bunch  of  minute,  ivhite,  acute  spines  (fig.  66;  the  line 
below  is  1  mill.  long). 

Length  46-50,  breadth  25  mill.;  divergence  125°. 
Unalaxhka,  Aleutian  Is.  (small  and  rare)  to  Sitka,  and  tout  I 

I  to  Monterey,   California;  low  water  to  20  fms.  on  stones  and 
shells. 


Chiton  d/lntus  SOWERBY,  Ann.  and  Mag.  Nat.  Hist.  1840,  p. 
289;  Conch  Illustr.,  f.  79  (1840).  Not  Chiton  ciliatus  Reeve,  nor 
Moi»'li'i  rilinta  Dall.  —  Chiton  wosnestemkii  MIDD.  Bull  Acad.  Imp. 
Sci.  St.Pe"tersb.  iv,  p.  119,  1847.—  Chiton  (Hamachiton,  Platysenuis) 
wosnessenskii  MIDD.,  Mai.  Ross.,  i,  p.  34,  101,  t.  11,  tl-2.—MopaKa 
«rleyi  CPR.,  Suppl.  Rep.  Brit.  Asso.  Adv.  Sci.  1863,  p.  648  ; 
Proc.  Acad.  Nat.  Sci.  Phila.,  1865,  p.  59.  —  M.  (kennerleyi  rar.) 
Swannii  CPR.,  Ann.  Mag.  N.  H.  xiv,  p.  426,  1864  ;  Suppl.  Rep.  B. 
A.  p.  648.  —  Mopalia  grayi  CPR.,  I.e.  p.  603  (name  only).  —  Mop"  /in 
wos8ne8*cn.*kn  Midd.,  BALL,  Proc.  U.  S.  Nat.  M  us.  1878,  p.  305 
(1879). 

This  species  is  distinguised  from  .17.  IMUMOM  and  its  immediate 
allies  by  its  color;  by  the  lack  of  that  narrow  anterior  projection 
of  the  outer  layer  at  the  sinus,  so  conspicuous  in  the  detached 
valves  of  the  typical  mu*cosa;  by  the  encroachment  of  the  wide  gir- 
dle at  the  sutun-,  the  deeper  caudal  wave  of  the  tail  valve,  and 
especially  by  the  brom'  '  it  urn  I  plates. 


IM.\<  ii-ir<»i:i;i  i  \.  :;or> 


This  last    -or  ins  to  be   a  constant    character,  and    tin;  prmliant 
the  tail  valve  noticed  above  is  also  rcliahl.-  ;   l>nt  i  arhni.-nt 

of  the  girdle  at  the  sutures  is  seen  al->  in  .!/.  Kindrii  :  tin-  la<-k 
anterior  projection  or  "  false  beak  "is  characteristic  of  many  varie- 
ties of  HI  a.  <r<  >.<•!,  such   as  the  elevated  var.  of  injiingn  found  at  Olyin- 
pia,  Washington,  and  the  var.  acuta  Cpr.  from  southern  (  'ulifornia. 
The  girdle  covering  presents  a  peculiarity  not  hitherto  not! 
near  the  base  of  each  of  the  curled  brown  hairs,  there  is  a  bunch  of 
tiny  white  thorns  or  spines.      These  are  also  numerous  at  the  edge 
of  the  girdle,  which  is  seen  slightly  rolled  upward  in  fig.  66. 

Dr.  Carpenter  studied  the  specimens  of"  C.  c/V////»/x  "  in  ('inning's 
collection,  and  found  them  to  be  genuine  w<<  and  therefore 

Ball  in  his  report  on  the  Chitons  of  Alaska,  as  well  as  other  Ameri- 
can writers,  accepted  the  name  ciliata  in  place  of  muscwft.  Unfor- 
tunately, the  Cumingian  specimens  are  not  the  true  ciliatu*  of 
Sowerby,  although  described  and  figured  as  such  by  Reeve.  The 
original  C.  ciliatus  is  identical  with  the  small,  green  black-mottled 
form  of  "  wosnessenskii  "  found  at  Monterey,  etc. 

An  excessively  rare  monstrosity  is  shown  in  fig.  67,  representing 
a  seven-valved  specimen,  in  which  the  reduced  number  is  not  due  to 
injury  or  coalescence  of  valves,  each  valve  being  completely  normal 
both  outside  and  within.  This  figure,  and  figs.  64,  65,  are  drawn 
from  Monterey  Bay  specimens.  The  sculpture  (fig.  68)  is  stronger 
and  sharper  in  typical  ciliata  than  in  the  VB.T.  wosnessenskii  (fig.  72). 

Var.  WOSNESSENSKII  Midd.     PI.  64,  figs.  69-73. 

Shell  elongated,  the  back  roundly  arched  not  carinated  ;  dull 
colored,  varying  from  light  olive  or  green  to  drab,  generally  with 
blackish  patches  on  each  side  of  the  middle,  and  more  or  less  mot- 
tled throughout  with  dusky.  Sculpture  much  fainter  than  in  ti/j)ic<il 
ciliata.  Girdle  apparently  lacking  the  white  spicules  described 
above. 

Sitka  (Wosnessenski,  figs.  69-71);  Olympia,  Washington  (Hemp- 
hill,  figs.  72,  73). 

This  seems  to  be  recognizably  distinct  from  the  typical  ciliata 
from  Monterey,  etc.  American  authors  have  hitherto  given  Wos- 
nessenski an  s  too  many. 

Genus  XXX.    PLACIPHORELLA  Carpenter. 

Placiphorella  CPR.,  MS.  in  Ball,  Proc.  U.  S.  Nat.  Mus.  1878,  p. 
303,  306.     Type  P.  velata  Cpr. 
20 


306  ri..U  Il'IIORELLA. 

Valve-  very  broad  and  short,  tin-  middle  ones  much  broader  than 
those  toward  the  ends;  head  valve  narrowly  cresc-entic,  tail  valve 
still  smaller,  with  interior  mucro.  Sinus  small ;  insertion-plates 
short  and  thick,  the  teeth  lobed  or  rugose.  Slits  8  or  more  in  the 
anterior,  1  in  the  median,  2  in  the  posterior  valve,  which  has  also  a 
shallow  posterior  sinus.  Eaves  spongy.  Girdle  widest,  often  very 
wi<le.  in  front,  bearing  sparsely  scattered,  scaled  hairs. 

This  genus  differs  from  Mojmlia  in  the  rotund  contour  of  the 
valves  taken  together,  and  their  extreme  shortness  individually,  as 
if  the  shell  had  been  crowded  together  from  the  ends.  The  slits  are 
practically  as  in  Mopalia,  being  normally  (or  at  least  originally)  8 
in  the  head  valve  ;  but  this  number  is  frequently  increased  by  the 
splitting  of  some  teeth.  The  mantle-edge  is  produced  in  front  and 
fringed  with  long  fleshy  finger-like  processes.  The  larger  hairs  of 
the  girdle  are  extremely  peculiar,  being  covered  with  imbricating 
scales  like  a  snake  skin,  on  a  corneous  core.  Nothing  of  the  sort 
has  been  found  in  any  other  group  of  Chitons. 

Carpenter  originally  intended  this  genus  to  include  forms  havim: 
hair-pores  at  the  sutures,  regardless  of  the  other  characters  of  valves 
and  girdle  ;  but  the  presence  of  pores  is  not,  in  Placiphorella  and 
M»j>'ilin,even  a  constant  specific  character. 

The  species  are  separated  by  rather  slight  characters  and  owing 
to  the  rarity  of  specimens  in  collections,  we  are  not  yet  prepared  to 
say  to  what  extent  the  characters  will  hold  good. 

P.  VI.I.ATA  Carpenter,  n.  sp.     PL  66,  figs.  6-12. 

-  .ell  roundly  oval,  broad,  rather  depressed,  quite  obtusely  angled. 
Surface  lusterless.  Light  colored  along  the  middle,  mainly  oliva- 
ceous on  the  sides,  especially  the  lateral  areas;  the  central  areas 
variou-ly  streaked  longitudinally  with  buff,  blue,  chestnut  and 
pink. 

Median  valves  not  beaked,  marked  by  growth  lines  ;  the  lateral 
areas  somewhat  raised,  having  a  rounded  wide  diagonal  rib  and 
another  at  thesutural  margin,  the  space  between  them  more  or  less 
excavated.  Central  areas  having  a  "  false  beak  "  or  narrow  pro- 
jection  fonvard  at  the  dorsal  ridge  (only  visible  when  the  valve-  an* 
separated.)  Anterior  valve  crescent  shaped,  sculptured  with  liirht 
concentric  growth-lines  only.  Posterior  valve  small,  slightly 
waved  inward  behind,  the  mucr<>  >vard,  recurred  and  elevated, 

the  slope  in  front  of  it  concave  in  profile,  unless  the  mucro  is  eroded. 


PLA<  ii'H'.i:i  : 

Interior  white,  slightly  blur  tinted.     > 
sented  by  a  very  8/t>il/> 

fi;i  a  /t/ittr  irliirl,  jill.<  the  .S////M  II h-  a  key-st<>' 
vii  to  viii  tin-  Him-  i-  derper  and  more  <\\<\  inct  I y  angular, 
valve    having*   slit-,  th'1  teeth    ohtuse,   short,  often  l.ilohed  or   COD- 
spieuously  rugose.    Central  valves  having  1  slit,  teeth  wedge-shaped, 
thicker  at    the  edges  of  the  slit.     Posterior  valve   having  a  very 
heavy  callus  supporting  the  short,   rugose  insert ion-plate,   which    i- 
i n ten- n pted  posteriorly  by  a  broad,  shallow  sinus,  and  ha-  1   -lit  on 
each  side  (occasionally  two  on  one  side). 

Girdle  very  hroad  in  front,  reddish,  fading  to  yellow  toward  the 
outer  edge,  irregularly  and  sparsely  beset  with  scaly  hairs  (fig.  13), 
of  which  one  or  two  are  generally  to  be  seen  in  each  suture  ;  a  close 
fringe  of  short  (broken)  hairs  adorns  the  girdle-edge. 

Length  50,  breadth  38  mill. ;  divergence  135°. 

Length  30,  breadth  24  mill. ;  divergence  130°. 

Humboldt  Bay  (Newcomb)  and  Monterey  Bay  (Canfield,  Hemp- 
hill,  et.  al.),  California;  Todos  Santos  Bay,  Lower  California  (Hemp- 
hill). 

Placiphorella  velata  CPR.,  MS.— DALL,  Proc.  U.  S.  Nat.  MILS. 
1878,  p.  303,  307  (description  of  animal) ;  p.  298,  t.  2,  f.  36,  a 
(dentition). 

This  species  is  distinguished  from  the  the  next  by  its  differently 
formed  posterior  valve,  by  the  connection  of  the  sutural  plates 
across  the  sinus,  and  the  anterior  projection  of  the  tegmentum  at 
the  sinus.  The  largest  specimens  I  have  seen  were  collected  by 
Hemphill  at  Todos  Santos  Bay. 

Fig.  12  represents  the  insertion-plates  of  an  intermediate  valve 
seen  from  their  summits,  showing  the  subtriangular  form  of  the 
posterior  insertion-tooth,  the  non-thickened  edges  of  the  slit,  etc. 

P.  STIMPSONII  Gould.    PI.  62,  figs.  84,  85,  86,  87. 

Shell  broadly  oval,  depressed,  subangular,  with  straight  side- 
slopes.  Color  whitish  along  the  middle,  the  sides  mottled  and 
streaked  with  greenish-yellow,  olive  and  blue,  the  colors  so  blended 
as  to  give  a  general  effect  of  dark  olivaceous. 

Valves  not  beaked,  sculptured  with  unequal  growth-lines. 
Lateral  areas  having  a  moderately  prominent  diagonal  rib,  with  an 
inconspicuous  wider,  lower,  sutural  rib,  the  space  between  excavated. 
Anterior  valve  narrowly  crescentic,  concentrically  striated,  but 


308  PLACIPHORELLA. 

lacking  all  radiating  sculpture.  Posterior  valve  (figs.  84,  85)- 
depressed,  the  mucro  near  the  posterior  margin,  which  is  slightly  and 
rather  broadly  waved  inward. 

Interior  delicately  blue-green  tinted.  Sinus  a  rather  shallow 
rounded  wave  in  the  earlier  valves,  becoming  deeper,  narrower  and 
angular  in  the  eighth  valve.  Anterior  valve  having  8  slits,  median 
valves  having  1  slit  on  each  side ;  the  eaves  narrow,  tenaciously 
adhering  to  the  girdle. 

Posterior  valve  small,  its  greatest  width,  including  insertion  and 
sutural-plates,  measuring  hardly  more  than  one-half  the  width  of  the 
widest  median  valves  ;  the  short  posterior  insertion-plate  rising  from 
a  very  heavy  callous  rim  ;  having  one  oblique  slit  on  each  side,  and  an 
almost  imperceptible  wave  where  the  posterior  sinus  should  be. 

Girdle  rather  narrow,  brown,  leathery,  sparsely  beset  with  spinu- 
les  (the  stumps  only  remaining  in  the  specimen  before  me),  of  which 
there  is  one  at  each  suture  and  a  marginal  fringe. 

Length  17,  breadth  12*  mill.;  divergence  140°. 

Hakodadi  Bay,  Japan  (Stimpson),  in  25  fms. 

Chiton  (Mopalia)  stimpsoni  GOULD,  Proc.  Bost.  Soc.  N.  Hist., 
vii,  p.  165  (1859)  ;  Otia  Conch,  p.  118.— Con/.  DALL,  U.  S.  Nat. 
Mus.  1886,  p.  210. 

The  above  description  is  from  the  type  in  the  U.  S.  National 
Museum  (no.  1646).  It  will  be  seen  that  the  species  differs  from  P. 
borealis  in  the  smooth,  not  radially  sculptured  anterior  valve,  in 
the  strongly  calloused  interior  of  the  posterior  valve,  its  shallower 
tail  sinus,  etc.  The  P.  velata  Cpr.  of  California  has  the  valves  very- 
similar  to  this  species  in  form  ;  both  differing  widely  from  P.  bore- 
alls  in  the  solid,  not  spongy,  sinus,  partly  filled  by  a  short  lamina 
connecting  the  sutural  plates ;  in  the  more  calloused  interior  of  the 
posterior  valve  and  its  smaller  size  ;  the  non-radiated  anterior  valve, 
etc. 

Carpenter  has  given  the  following  notes  in  his  MS.  on  a  fine 
specimen  from  Japan,  in  the  Jeffreys  collection.  "  As  curled  up 
and  dried  it  measures,  length  23,  breadth  21  mill. ;  divergence  120°. 
It  is  olivaceous  and  orange-ash  variegated.  Anterior  valve  smooth. 
Posterior  valve  having  the  mucro  raised,  at  the  posterior  third,  the 
sinus  continued  upward  to  it  outside.  Central  valves  with  two 
obsolete  but  swollen  ribs,  one  sutural,  the  other  diagonal,  with  a 
broad  depression  between  them.  The  girdle  is  very  much  shrivelled 


PI . \.  i ni'  i  :joi» 

and  the  head  rxpansion  dotihled  up,  but  tin-  hair.-  :in-  very  well 
preserved.  Over  the  whol.-  of  tin-  mar-innl  p:t 
crowded  deciduous  whitish  luiirs.  Over  the  greater  portion  of  the 
surface  are  scattered  distant  lar^e  tnlndar,  horny  hair-,  which  seem 
to  arise  deep  in  the  girdle.  Th»>,-  hairsan-  not  scaly  an  in  I'.  A///m- 
I'illti,  l)Ut  present  when  perfect  the  aspect  of  A«pr.nj HI" in  i-'iyim'fcrum 
in  miniature.  I  eann.it  >ay  with  confidence  that  all  the  hairs  are 
so  sculptured,  for  some  which  look  perfect  do  not  show  it.  " 

A.  sketch  made  by  Dr.  Carpenter  from  a  hair  of  this  specimen  is 
•copied  on  pi.  62,  fig.  86.  The.  hairs  on  Gould's  type  are  broken  to 
very  short  stumps,  not  long  enough  to  show  their  structure. 

P.  BOREALIS  Pilsbry,  n.  sp.     PI.  66,  figs.  14,  15,  16,  17. 

• 

Shell  similar  in  general  characters  to  P.  velata.  Brown  at  the 
sides,  light  along  the  middle.  Surface  dull,  showing  growth- 
lines. 

Valves  not  beaked,  having  a  slight  forward  bend  in  the  middle 
at  the  sinus,  but  not  "  false  beaked  "  there  as  P.  velata  is.  Lateral 
areas  more  strongly  2  ribbed.  Anterior  valve  sculptured  with  numer- 
ous very  low,  wide  radiating  riblets.  Posterior  valve  having  the 
mucro  near  the  posterior  margin,  depressed,  the  slope  in  front  of  it 
rising,  convex  rather  than  concave ;  posterior  margin  waved 
inward. 

Interior  light  blue-green.  Sutural  plates  separated  in  all  the 
valves  by  an  angular,  spongy  sinus.  Anterior  valve  having  11  slits, 
the  teeth  unequal,  lobed  or  roughened.  Median  valves  having  one 
slit,  the  teeth  being  peculiar  1 1/  curbed  outward  at  its  edges.  Posterior 
valve  much  less  callous  inside  than  that  of  P.  velata,  the  insertion- 
plate  uneven,  roughened,  but  having  a  single  well  developed  slit  on 
each  side ;  the  median  tail-notch  deep  and  wide.  Eaves  very 
spongy.  Girdle  unknown  to  me. 

Breadth  of  anterior  valve  16,  length  of  front  slope,  including 
teeth  4J  mill. 

Breadth  of  a  median  valve  22,  length  from  sinus  to  beak  4*  mill. 

Breadth  of  posterior  valve  15,  length  direct  from  sinus  to  sinus 
5  mill. 

Divergence  135°.  Measurements  of  breadth  include  the  inser- 
tion-plates. 

Bering  Island,  Bering  Sea  (Grebritzki). 

Placiphorella  stimpsoni  DALL,  (part),  Proc.U.S.  Nat.Mus.  1886 


310  PLACIPHORELI.A. 

p.  210.     >  uld. 

This  t'.»rm  iskiiuwn  to  UK-  liy  tin1  valves  of  a  single  individual,  no. 
uithsoniau  register.  It  differs  from  P.  vel-atn  in 
the  greater  prominence  of  the  lateral  ribs,  the  curiously  excurved 
teeth  of  the  side  insertion-plates  (fig.  15),  the  less  calloused  interior 
of  the  posterior  valve,  and  its  very  different  form.  Compare  fig.  9 
with  riir.  H>,  the  former  representing  the  tail  valve  of  P.  velata,  the 
latter  that  of  P.  borealis.  Some  other  differences  are  indicated  in 
the  descriptions.  In  this  specimen  the  slit  on  one  side  of  the  pos- 
terior valve  is  nearly  obsolete. 

P.  BLAINVII.LII  Broderip.     PL  66,  figs.  26-32. 

Shell  ovate,  very  broad,  depressed ;  variously  clouded,  streaked 
and  maculated  with  rosaceous  and  olivaceous  or  red-brown,  gener- 
al Iv  tessellated  at  the  sutures. 

Median  valves  hardly  beaked.  Jugal  areas  sometimes  defined  by 
an  obsolete  v-shaped  sulcus.  Central  areas  appearing  a  trifle  and 
most  minutely  granulate  under  a  lens,  otherwise  smooth  and  shining. 
Lateral  areas  slightly  swollen,  concentrically  marked  by  ribs  of 
growth  ;  margins  of  valves  rounded,  the  sutures  not  very  deep 
except  in  young  specimens.  Posterior  valve  having  the  mucro  pos- 
terior, almost  terminal ;  the  posterior  sinus  of  the  valve  wide  and 
shallow. 

Interior :  anterior  valve  having  8  slits,  the  teeth  rather  short  and 
roughened  or  crenulated  outside.  Posterior  valve  having  a  single 
slit  on  each  side.  Median  valves  with  1  slit;  the  sutural-plates 
rather  straight  and  narrow,  sinus  a  shallow  wave. 

( .irdle  thin,  very  broadly  expanded,  in  front,  narrow  and  not 
sinuous  behind.  Surface  having  sparse,  comparatively  short  hairs, 
which  in  drying  become  appressed  on  the  girdle,  each  hair  appearing 
scaly  under  the  microscope,  like  a  snake's  skin  (fig.  28).  The  hairs 
are  not  especially  sutural  in  position,  suture-pores  being  absent  in 
adult  examples  ;  nor  do  hairs  occur  in  bunches  anywhere.  Besides 
these  scaly  hairs,  there  are  scattered  chaffy  hairlets  (which  in  one 
specimen  more  contracted  than  the  rest  are  gathered  into  little 
bunches.) 

Length  50,  breadth  36  mill. ;  divergence  147°. 

Inner  Lobos  Island  (Lobos  de  Tierra'),  Peru,  on  stone  in  17  fms. 
(Cuming.) 

Chiton  blain>;>/;;  BltOD.,  I'.  Z.  S.  \W,  p.  27.— SOWERBY,  Conch. 


[PHOBB]  i.\    PLAXIPH4  ••!  1 

r.  S.     Ui  i  \  i .  G  uah.  [oon.,  t,  I,  i'.  i 
i/  GRAY,  r.  /..  U—Jfopafta   ! 

J/\  MII.I  in  I) M.I,,  Proa  l'.  8,  Nat.  MUH.  1878,  p.  303.— / 

hUnmllii  DAM,,  /.  c.  1886,  p.  210,  21 1. 

This  lurm' sp.vir- i-  nearly  allied  (..  /'.  ,-.  f<tta  of  ( 'alifornia,  hut  it 
diti'rrs  in  having  the  lateral  areas  simply  x.nit-u  hat  swollen,  and  Dot 
excavated  in  tin-  middle.  Tin-  sinus  between  the  sutural  plates  is  a 
shallow  wave,  lmt  it  deepens  mi  the  two  or  three  backward  valves, 
as  in  the  Californian  species.  The  description  iriven  above  is  com- 
piled from  Carpenter's  notes  on  the  type  specimens. 

P.  I-I-:TASUS  Reeve.    PL  66,  fig.  25  (enlarged.) 

Shell  small,  somewhat  abbreviately  ovate.  Valves  with  a  polished, 
slightly  beaked  triangular  area  in  the  center,  roughly  granulated  on 
each  side.  Bright  scarlet.  Ligament  very  broad,  especially  in  front, 
also  bright  scarlet,  beset  here  and  there  with  short  hairs  and  bristles. 

Length  1,  breadth  1  inch,     (five.) 

Cape  Eivers,  Celebes  (Belcher.) 

Chiton  pet««u8  REEVE,  P.  Z.  S.  1847,  p.  25 ;  Conch.  Icon.,  t.  ?6, 
no.  114,  fig.  112,  (not  112  on  plate  of  details,  nor  114)  ;  July,  1847. 
ADAMS  &  REEVE,  Zool.  of  the  Voy.  H.  M.  S.  'Samarang/  Moll., 
t.  15,  f.  11. 

Referred  to  this  genus  on  account  of  the  peculiar  girdle.  A  single 
specimen  was  collected.  The  characters  of  the  interior  have  riot 
been  made  known. 

Genus  XXXI.     PLAXIPHORA  Gray,  1847. 

Plaxiphora  GRAY,  P.  Z.  S.  1847,  pp.  65,  68,  169.— SHUTTLES  ., 
Bern.  Mittheil.  1853,  p.  69.— H.  &  A.  ADAMS,  Gen.  Rec.  Moll,  i, 
p.  481.— Placiphora  CPR.,  MS.  and  in  DALL,  Proc.  U.  S.  Nat.  Mus. 
1881,  p.  284.— Placophora  DALL,  Cat.  Mar.  Moll.  S.-E.  U.  S.,  p.  1 74  ; 
not  Placophorm  Mulsant,  1873  (Trochilidce'). — Eupfaxiphora  SHUT- 
TLEW.,  1.  c.,  (proposed  for  biramosus  and  petholatus). — Eiiplndphora 
CPR.,  /.  c.,  (type  P.  petholatd). —  Ch'jdopleura  (part)  ROCHEBRUNE, 
Miss.  Sci.  du  Cap  Horn,  1882-1883,  vi,  Zool.,  Polyplacophores,  p. 
135  (1889),  not  Chcetopleura  Shuttlew. ! 

Valves  mostly  exposed,  all  having  insertion-plates  developed,  that 
of  the  anterior  valve  normally  with  8  (sometimes  7-9)  slits  (except 
in  the  subgeuus  Placophoropsis  which  has  many  slits).  Median 
valves  1  slit.  Posterior  valve  having  the  insertion-plate  smooth, 


312  PLAXIPHORA. 

;.  interrupted  behind  by  a  median,  rounded  sinus,  which  does 
not  generally  enmrginate  the  tegmentum;  mucro  posterior.  Girdle 
bearing  simple  bristles  or  hairs,  scattered  or  gathered  into  pores  or 
tufts  at  the  sutures.  Type  Chiton  setiger  King. 

This  genus  is  most  nearly  allied  to  Mopalia  and  Placiphorella,  from 
both  of  which  it  differs  in  the  unslit  insertion-plate  of  the  tail  valve. 
The  peculiar  girdle-bristles  of  Placiphorella  are  an  additional  char- 
acter separating  the  genera. 

In  Plaxiphora,  as  in  Mopalia  and  Placiphorella,  the  bristles  of  the 
girdle  are  indifferently  scattered  or  gathered  into  sutural  bunches. 
This  character  is  of  specific  value  only  when  strongly  developed ; 
and  each  of  the  three  genera  contain  species  which  in  occasional 
individuals  develop  pores,  or  species  usually  poriferous,  but  varying 
to  poreless.  This  distinction,  which  Blainville,  Gray  and  the  Adams 
brothers  considered  fundamental,  is  therefore  of  comparatively  tri- 
vial importance. 

Plaxiphora  is  divisible  into  a  number  of  minor  groups,  as  follows: 

Subgenus  PLAXIPHORA  (restricted.) 

Slits  of  anterior  valve  normally  8  (sometimes  7  or  9  by  coales- 
cence or  splitting),  coresponding  in  position  to  external  ribs ;  the 
teeth  long  outside.  Girdle  widest  at  the  sides.  Mantle  not  fringed 
in  front  of  the  head.  Distribution,  Southern  extremities  of  the 
southern  continents ;  living  in  the  littoral  zone. 

This  subgeuus  although  rather  homogeneous,  may  conveniently  be 
divided  into  three  sections,  as  follows : 
Section  I.  Plaxiphora,  restricted  (=Euplaciphora  Shuttl.  not  Cpr.). 

Valves  exposed.      Entire  shell  normal  in  form  ;  posterior  valve 

not  greatly  reduced  in  size  or  altered  in  form. 
Section  II.   Guildingia  Cpr.      Valves  partially    immersed   in  the 

girdle,  which  encroaches  at  the  sutures. 
Section  III.  Fremblya  H.  Ad.      Valves  exposed.      Shell  short  and 

broad  ;  the  posterior  valve  reduced  to  a  narrow  crescentic  form, 

and  seen  to  be  strongly  arched  upward  if  viewed  from  behind. 

Subgenus  PLACOPHOROPSIS  Pilsbry. 

Slits  of  anterior  valve  numerous  (about  20)  ;  teeth  very  short. 
Girdle  widest  and  much  dilated  in  front.  Mantle  produced  into 
several  long  finger-like  processes  in  front  of  the  head.  Distribution, 
Northwest  Atlantic ;  living  in  deep  water. 


i  i .\\n-iroRA.  313 

Subgenu-  PI,A<  <>i'ii<>i:<»rMs  I'iMu-y,  1 893  (n.  s.-g.) 

Shell  short,  ol.Mvatr.  t  lit-  valves  short  and  \\  !<!<•  ;   li:i\  in;_r  v 
almost  obsolete  insertion-plates,  th:it  of  the  anterior  \:(l. 
many  (about  20)  shallow  notches  ;  posterior  valve  with  callous  ridges 
at  the  sides  and  a  shallow  rounded  caudal  >inns.     ( iirdle  enormously 
liroadeiied  in  front,  narrow  In-hind. 

This  section  is  intcn liate  between  Placiphorella  and  P/'is!j>hora, 

•differing  from  both  and  from  and  all  M<i]m/iiil<r,  in  the  multiplica- 
tion of  anterior  slits,  although  some  specimens  of  Placiphorella  show 
the  same  tendency.  It  must  be  understood  that  although  in  many 
groups  of  Chitons,  such  as  all  MinorhHoniinr  and  Chitonince,  the 
number  of  anterior  slits  is  a  character  of  merely  specific  importance, 
the  case  is  far  otherwise  in  those  groups  in  which  the  slits  correspond 
in  number  and  position  with  external  ribs,  such  as  Nutfallina  and  its 
allies,  and  the  MnpnUldn ,  Acanthochitidce,  etc.  In  these  groups  the 
number  of  slits  in  the  anterior  insertion-plate  is  a  highly  constant 
generic  character,  apparent  exceptions  being  generally  readily  trace- 
able to  the  splitting  of  one  or  more  primary  teeth. 

Besides  the  character  just  discussed,  Placophoropsis  resembles 
Placophorella  in  the  form  of  the  girdle ;  but  it  differs  in  lacking 
Mopaloid  slits  in  the  posterior  insertion  plates.  Placophoropsis 
resembles  Plaxiphora  in  the  non-slit  posterior  insertion-plate,  but  it 
differs  in  the  obsolescence  and  multiple  slitting  of  the  anterior  inser- 
tion plate,  and  in  the  anterior  dilation  of  the  girdle. 

The  obsolescence  or  shortness  of  the  insertion-plates  in  this  form 
is  evidently  due  to  degeneration  from  disuse.  Deep  sea  Chitons  not 
being  subjected  to  the  constantly  recurring  impacts  and  stresses 
which  affect  littoral  forms,  have  no  need  of  elaborate  structures  for 
binding  the  valves  in  their  places.  Consequently  the  primitive 
forms,  such  as  Lepidopleurus,  have  been  able  to  survive  unaltered 
under  these  conditions.  In  the  case  of  Placiphoropsis,  which  is 
descended  from  littoral  forms  having  long,  well-developed  insertion 
plates,  especially  in  the  anterior  and  median  valves,  the  shortness  of 
the  plates  is  to  be  ascribed  to  the  absence  of  the  external  stimuli 
which  act  constantly  upon  the  littoral  Mopaliidce. 

P.  ATLANTICA  Verrill  &  Smith.     PL  66,  figs.  18-24  ;  pi.  65,  figs,  73, 
74,  75. 

Shell  obovate,  wider  in  front,  tapering  toivard  the  small  posterior 
valve,  which  is  only  about  half  as  wide  as  the  anterior  valve.  Rather 


314  PLAXIPHORA. 

depressed,  roof-shaped,  the  dorsal  ridge  angular,  side  slopes  slightly 
convex.  Color  pale  brown,  whitish  along  the  middle  and  at  the 
edge.  Girdle  extremely  wide  in  front,  narrow  behind,  dark  brown 
in  alcoholic  specimens. 

Median  valves  very  wide  and  short,  a  trifle  beaked  in  the  middle- 
Lateral  areas  strongly  elevated,  the  diagonal  slope  abrupt ;  slightly 
excavated  in  the  middle,  obsoletely  granulated.  Central  areas  hav- 
ing rather  inconspicuous  growth-lines  and  an  obsolete  or  nearly 
effaced  granulation.  Anterior  valve  very  short  and  broad,  having 
many  faint  radiating  riblets  and  obsoletely  granulated  throughout. 
Posterior  valve  small,  with  posterior,  slightly  elevated  mucro,  and 
elevated  postero-lateral  ribs. 

Interior  white.  Sinus  very  narrow,  square.  Insertion-plates  very 
short,  almost  subobsolete,  that  of  the  anterior  valve  wide,  calloused, 
having  about  20  irregular  and  excessively  shallow  notches  (hardly 
slits),  obsolete  toward  the  ends ;  median  valves  with  1  slit.  Poste- 
rior valve  having  a  low  wide  callous  ridge,  slightly  rugose,  and  in 
the  middle  interrupted  by  a  shallow  rounded  sinus  (pi.  65,  figs.  73- 
75.) 

Girdle  "  very  broad  anteriorly  and  narrow  posteriorly.  It  increases 
gradually  from  the  posterior  end  to  a  point  opposite  the  fifth  plate, 
where  it  suddenly  expands  into  a  broad  round  front,  with  the 
breadth  one-third  greater  than  the  greatest  breadth  of  the  shell.  It 
is  thick,  leathery  and  scabrous,  everywhere  closely  covered  with 
minute  spinules;  the  lower  surface  anteriorly  showrs  many  radiating 
grooves  (not  distinct  in  the  smaller  examples) ;  between  these  are 
rows  of  slightly  raised  small  verruca,  covered  with  small  spinules. 
The  inner  edge,  or  mantle-border,  is  sharply  defined,  enclosing  an 
elliptical  area  around  the  head  and  gills,  with  a  well  marked  poste- 
rior sinus ;  its  front  edge  is  divided  into  about  seven  digitations,  the 
anterior  ones  rather  long,  tapering,  and  tentacle-like  but  coriaceous 
and  covered  with  fine  spinules,  like  the  rest  of  the  marginal  mem- 
brane. Cephalic  hood  large,  broad-lunate ;  foot  relatively  small, 
ovate.  Gills  numerous  (in  the  largest  about  sixteen  on  each  side), 
extending  nearly  the  whole  length  (more  than  two-thirds)  of  the 
foot,  but  reaching  neither  end  of  it." 

Length  of  largest  specimen  (alcholic)  32,  breadth  26  mill. ;  length 
of  shell  21,  breadth  18  mill.  Divergence  130°. 

N.  lot.  40°  01',  Jr.  I.,,,./.  68°  54',  in  MO  f**^  off  Nantueket  bland, 
and  in  N.  lat.  42°  15'  25",  W.  long.  65°  48'  40",  in  122 /m«.,  off  ^  » 


.iriroRA. 

(U.  S.  Fi>h  <  \  ll.aln..-s ',  1883.) 

Placoph  AiiM-r.   JotHI 

:ice  xxiv,  Nov.,  iw,  p.  :;•;.'»  (fbotoot  theC/oni 

mt   A. -ad. -my  O/  Natural  >.-i.-n.-,  ,.  vi.  p.  2  f.  1.  hi,  1  A.  ^ 

1884).— Placophnrn  <itl,mtic<i  V.  ,V  S..  DM  i..  Hull.  :;7,  U.  S.  Nat. 
Miis..  p.  171,  t.  l.»,  f.   la,  6;  t.  63,  f.  102,  102a  ( repp,diir-d  ; 
Verrill  &  Smith. 

A  vt-ry  peculiar  species.  The  tiiruivs  of  tin-  tail  and  head  plates 
given  by  Verrill  and  copied  on  plate  G«)  are  not  very  good,  and  I 
have  therefore  drawn  others  from  one  of  the  original  specimens,  on 
pi.  65. 

The  only  specimen  of  this  species  which  I  have  examined  has  a 
deep  cleft  in  the  posterior  margin  of  the  tegmentum  of  the  tail  valve, 
parallel  to  the  lower  border  of  the  valve.  Whether  this  is  or  is  not 
abnormal  must  be  decided  by  the  examination  of  more  material. 
It  is  well  shown  in  fig.  74,  of  plate  65. 


Subgenus  PLAXIPHORA  Gray. 
Under  this  subgenus  three  sections,  defined  above,  are  placed. 

Section  Plaxiphora  Gray. 

This  section  as  here  restricted  corresponds  to  Gray's  original 
genus,  except  that  he  was  ignorant  of  the  fact  that  sutural  pores  or 
tufts  are  absent  in  some  species.  It  is  absolutely  equivalent  to 
Shuttleworth's  section  Euplaxiphora,  but  Carpenter  restricted  this 
last  name  to  species  of  the  P.  petholata  type,  having  no  pores  or 
tufts  at  the  sutures.  The  mutability  of  this  character  has  been  dis- 
cussed under  Mopalia ;  therefore  it  is  necessary  in  this  place  merely 
to  state  that  the  presence  of  pores  at  the  sutures  is  not  even  a  con- 
stant specific  character  in  Plaxiphora,  except  when  the  tufts  are 
strongly  developed.  There  are  several  species  in  which  the  pores 
are  visible  in  some  specimens,  but  quite  absent  in  others  preserved 
in  the  same  way. 

The  corrugated  Plaxiphoras  are  in  great  need  of  revision  ;  but  the 
material  now  in  museums  is  insufficient.  Great  latitude  may  be 
expected  in  the  range  of  specific  variation,  as  in  the  genus  Mopalia. 

Partial  key  to  species  of  Plaxiphora. 
a.  Central  areas  unsculptured  save  for  growth-lines. 


316  n.AxiriiORA. 

6.  Sutural  pores  or  tufts  distinctly  developed;  sinus  shallow, 
c.  Anterior  valve  distinctly  ribbed  ;  lateral  areas  dis- 
tinct, setigcr,  biramosa. 
cc.  Anterior   valve    smooth  ;  lateral   areas    indistinct. 
Dark  brown,  banded  with  paler  at  the  ridge, 

simplex, 
bb.  Sutural  tufts  or  pores  absent. 

c.  Lateral  areas  undefined,  not  sculptured. 

d.  Sinus  deep,  narrow,  denticulate  ;  brown,  with 
a  yellow-bordered  dorsal  band  of  chestnut, 

wahlbergi. 

dd.  Sinus  wide,   smooth ;   black,   with    a  green- 
bordered  dorsal  black  triangle,  glauca. 
cc.  Lateral  areas  defined  by  a  beaded  rib,  concentric- 
ally wrinkled. 

d.  Colors  bright  and  variegated ;  size  small, 

carpenteri. 
aa.  Central  areas  corrugated,  at  least  at  the  sides, 

Group  of  P.  petholata. 
Group  of  P.  terminalit. 


Group  of  P.  setiger. 

Shell  smoothish ;  girdle  with  distinct  sutural  pore-bunches. 
P.  SETIGER  King.     PL  65,  figs.  76,  77,  78,  79. 

Shell  elliptical,  low  roof-shaped,  the  ridge  carinated,  side-slopes 
straight.  Surface  lusterless,  smooth  except  for  delicate  growth-lines. 
Color  ashy-olive  or  bluish,  with  concentric  dark  streaks,  and  gener- 
ally having  unequal  stripes  radiating  from  the  beak  of  each  valve, 
these  markings  varying  from  indistinct  to  conspicuous. 

The  median  valves  are  not  beaked.  Lateral  areas  not  raised,  but 
clearly  defined  by  a  narrow,  raised  diagonal  riblet,  and  perceptibly 
sivollen  or  ribbed  toward  the  posterior  margin,  'jiving  the  young  a 
bicostate  appearance ;  the  tiro  ribs  being  more  or  less  nodose,  especially 
in  yointg  specimens,  and  toward  the  beaks  in  adults;  and  there  are 
also  a  few  extremely  indistinct  radiating  riblets  in  the  slightly 
excavated  middle  portion  of  the  lateral  areas.  Central  areas  smooth. 
Anterior  valve  having  about  8  narrow  radiating  riblets,  becoming 
obsolete  as  they  near  the  peripheral  margin,  but  each  ending  in  a 


I'l    \  XM'IIORA. 

slight  projretion  there  ;   the  interval  -«.iii»-   iinli-ti: 

Posterior  valve  drpiv-nl,  tin-  muero  inruii.-pinioiH  and  about  at  the 
posterior  fourth  ;  posterior  aiva  ubsoletely  radi:it<-ly  ri!> 

Interior  light  blue  ^reen.  Sinus  small  and  shallow.  Sutural 
plates  low.  Anterior  valve  having  8,  central  valves  1  slit;  the  slits 
short,  continued  in  grooves  to  the  eaves;  teeth  long,  irregularly 
striated  outside,  thickest  along  the  slits,  sharp  edged.  Posterior 
valve  having  the  insertion-plate  long  and  stout  at  the  sides,  inter- 
rupted l>y  a  rounded  sinus  in  the  middle  behind;  its  edge  smooth, 
unslit.  Eaves  very  narrow  and  very  spongy. 

Girdle  rather  wide,  leathery,  having  at  each  suture  a  small  pore 
bearing  several  long  corneous  bristles,  and  with  one  or  two  more  or 
less  irregular  series  of  bristle-bearing  pores  on  the  surface  of  the 
girdle,  and  a  more  or  less  dense  clothing  of  small  soft  hairs  over  its 
outer  part. 

Length  50,  breadth  35  mill.;  divergence  125-135°. 

Chiton  setiger  KING,  Zoological  Journal  v,  p.  338  (1831). — Sow- 
ERBY,  Conch.  Illustr.,  f.  17 ;  Zool.  Beechey's  Voy.,  pi.  40,  f.  7  (bad). 
— REEVE,  Conch.  Icon.  t.  ix,  f.  48a,  t.  xiv,  f.  48c.— GOULD,  U.  S. 
Expl.  Exped.,  Moll.,  p.  330,  f.  425. — Plaxiphora  carmichaelis  GRAY, 
P.  Z.  S.  1847,  p.  68,  and  subsequent  writings,  probably  not  Chiton 
carmichaelis  GRAY,  Spic.  Zool.  1828. — Plaxiphora  carmichaelis 
HADDON,  Challenger  Report,  Polyplac.,  p.  32. — H.  &  A.  AD.,  Gen. 
Rec.  Moll,  i,  p.  481  ;  iii,  t.  55,  f.  3. —  Chcetopleura  savatieri  ROCHE- 
BRUNE,  Bull.  Soc.  Philomathique  de  Paris,  1880-1881,  p.  119; 
Miss.  Sci.  du  Cap  Horn,  Polyplacophores,  p.  135,  t.  9,  f.  3a,  3b. — 
Chwtopleura  frigida  ROCHEBR.,  Miss.  Sci.  du  Cap  Horn,  p.  137,  t.  9, 
f.  5a,  5b.  (young  shell.) 

This  is  the  only  well-established  species  known  to  inhabit  the 
extremity  of  South  America.  It  will  be  readily  recognized  by  the 
smoothness  of  the  surface,  strong  diagonal  rib,  and  generally  well- 
defined  sutural  pores,  each  bearing  several  bristles.  The  variation 
in  color  is  well-shown  on  the  plate.  The  C.  savatieri  (pi.  67,  figs. 
41,  42),  and  C.  frigida  (pi.  67,  figs.  39,  40)  of  Rochebrune  are 
merely,  it  seems  to  me,  individual  mutations  of  setiger  the  last  being 
a  young  shell.  It  will  not  escape  the  observant  zoologist  that  the 
artist  who  drew  the  plate  of  Chitons  illustrating  Rochebrune's  paper, 
did  not  see  the  lateral  slits  in  the  valves.  One  is  likely  to  infer  that 
the  other  characters  may  be  equally  erroneously  represented. 

Some  authors  have  given  Gray's  name  carmichaelis  to  this  species ; 


318  1'i.AxiriroRA. 

hut  this  identification  rests  only  upon  the  synonymy  given  in  Gray's 
several  lists.  Waiving  lor  the  moment  the  question  as  to  the 
identity  of  the  original  mnnicJutelis  with  setiger,  we  notice  that  the 
rest  of  Gray's  synonymy  of  this  species  is  in  several  respects  incor- 
rect. C.  biramosut  Quoy  for  instance,  is  not  the  same  as  *etiger ; 
and  his  list  of  Chitons  shows  a  number  of  other  errors  of  synonymy. 
It  is  not  safe  therefore  to  trust  Gray's  dictum  in  such  matters ;  and 
it  may  fairly  he  doubted  whether  the  original  cannirhaelis,  which  is 
described  as  being  "  scarcely  keeled,"  one-half  an  inch  long,  etc., 
etc.,  is  the  same  as  the  large,  strongly  carinated  Ch.  setiger.  In 
any  case,  Gray's  name  should  be  ruled  out  on  the  score  of  faulty 
definition.  The  name  setiger  was  acceptably  defined ;  the  species 
correctly  located  by  King;  and  it  was  sheer  piracy  on  Gray's 
part  to  shift  his  name  from  some  poor  little  half-inch  Cape  of  Good 
Hope  specimen  to  this  fine  large  form  from  Cape  Horn.  The 
original  description  of  carmichaelis  is  as  follows: 

Chiton  carmichaelis  Gray.  Shell  oblong,  convex,  scarcely  keeled, 
smooth,  bluish-brown  streaked  and  lined  with  white ;  front  valves 
with  distant  rather  broad  radiating  nodulose  ribs;  front  and  back 
margins  of  the  lateral  areze  of  the  middle  valves  with  a  single  similar 
rib  ;  hinder  valve  smooth.  Margin  scabrous,  brown.  Length  £  an 
inch,  breadth  |.  Icon.  Wood,  Cat.  Suppl.,  1. 1,  f.  10.  Inhab.  Cape 
of  Good  Hope.  Capt.  Carmichael,  Brit.  Mus. 

Chiton  carmichaelis  GRAY,  Spicil.  Zool.  pt.  1,  p.  6  (July  1,  1828). 
Not  ritu-ijthnra  carmichaelis  GRAY,  P.  Z.  S.  1847,  pp.  68,  169.— P. 
carmichaelis  GRAY,  Guide  Syst.  Dist.  Moll.  B.  M.,  p.  186. 

Var.  FRKMKI.YI  Broderip.     PI.  67,  figs.  37,  38. 

Shell  oblong,  flattened,  olivaceous-brown,  varied  with  whitish- 
green  lines ;  anterior  valve  with  elevated  subgranose  rays ;  inter- 
mediate valves  angular  at  the  sides,  the  lateral  areas  biradiate,  rays 
subgranose,  intervals  longitudinally  subsulcate.  Girdle  set  with 
numerous  short  bristles. 

Length  If,  breadth  1  inch.     (Brod.} 

Bay  of  Valparaiso  (Cuming). 

Chiton  frembleii  BROD.,  P.  Z.  S.  1832,  p.  28.—  C.  setiger  var. 
fremblii  SOWB.,  Conch.  Illustr.,  p.  7,  f.  4. —  Chcetopleura  huhni 
ROCHEBRUNE,  Miss.  Cap  Horn,  Polyplac.,  p.  136,  t.  9,  f.  4  (1889.) 

This  differs  from  P.  set'i<j<  /  in  being  somewhat  wrinkled  concentric- 
ally. I  have  not  seen  specimens.  Broderip  inserted  an  e  in  Frem- 


319 

l»ly's  name,  evidently  by  inadvertence. 

The  fiUMire~  represent    ('.  Imliui   Uuchebr.,  which    I    l.dic 
identical.      It  is  thus  described  : 

r/i/r/o//A-//m  h,ihni  [pi.  <I7,  li;rs.  37,  38].  Shell  broad-ovate,  flat- 
tened, «>btusely  carinated,  violaceous-bluish,  with  spots  and  lines  of 
brown  irregularly  distributed.  Anterior  valve  rounded,  with  10 
radiating  ribs.  Posterior  valve  very  small,  elliptical,  feebly  beaked. 
Lateral  areas  of  the  median  valves  narrow,  bounded  by  a  beaded 
rib;  central  areas  covered  with  deep  concentric  stria',  and  very 
minutely  striated  transversely.  Girdle  wide,  brown,  covered  with 
tawny  hairs.  Length  48,  breadth  35  mill.  (Rochebrune.} 

P.  BIRAMOSA  Quoy  &  Gaimard.     PL  68,  figs.  51-54. 

Animal  ovoid,  elongated,  flattened,  valves  very  transverse,  little 
elevated,  forming  a  low  arch,  not  carinated  ;  striated  transversely  in 
front.  White  or  green  with  a  circle  of  red-brown  on  each  valve. 
The  anterior  valve  has  9  teeth  on  its  edge,  the  posterior  valve  none. 
The  sutural  laminre  are  not  wide,  and  are  separated  only  by  a  very 
obtuse  sinus.  The  insertion  plates  are  slit  at  the  sides  at  usual.  Inte- 
rior dull  white. 

Girdle  nude,  vivid  red-brown,  having  two  spaced  series  of  rough, 
sparse  and  bifurcating  hairs,  the  inner  series  contiguous  to  the 
valves,  the  other  near  the  periphery  of  the  girdle,  which  is  also 
hairy.  (§.<£(?.) 

Length  45,  breadth  31  mill. 

Chiton  birnmosus  Q.  &  G.,  Voy.  de  FAstrol.  Zool.  iii,  p.  378, 
t.  74,  f.  12-16. — Plaxiphora  biramosa  Q.  &  G.,  HUTTON,  Man.  N.  Z. 
Moll.  1880,  p.  116  (translation  of  Quoy's  diagnosis). — Acanthochcetes 
lii-iimosus  HUTTON,  Trans.  N.  Z.  List,  iv,  p.  181  (incorrect  descrip- 
tion, from  Deshayes). — Pladphora  superba  CPR.  MS. 

The  external  form  is  noticeably  different  behind  in  the  two 
individuals  which  we  possess  ;  but  the  red  color  of  this  species  and 
its  two  series  of  bifurcating  spines  will  readily  distinguish  it.  ( Q. 
&  £.) 

I  believe  the  form  which  Carpenter  described  in  MS.  as  P. 
is   the   same   as   Quoy  and  Gaimard's   C.  biramosus.     Carpenter's 
description  is  as  follows  : 

P.  superba  (pi.  68,  figs.  55-61).  Shell  large,  oval,  elevated,  the 
dorsal  ridge  acute ;  mucro  subposterior,  little  elevated.  Reddish- 
olive,  maculated  with  darker  and  paler.  Valves  nearly  rectangular, 


320  I'LAXIPIIORA. 

but  well  indented  at  the  sutures,  having  a  "  false  apex  "  in  front. 
Lateral  areas  having  indistinct,  subobsolete  radiating  riblets.  Ante- 
rior valve  subangled  by  8  radii,  which  slightly  undulate  the 
peripheral  margin;  otherwise  nearly  smooth  except  for  growth- 
lines.  Interior  :  posterior  valve  having  the  insertion-plate  elevated, 
rounded,  interrupted  in  the  middle  behind  by  a  very  narrow,  deep 
sinus.  Anterior  valve  having  8,  central  valves  1  slit;  teeth  long,. 
slightly  striated  and  slightly  thickened  at  the  edges  of  the  slits  out- 
side. Sinus  narrow,  short.  Sutural  laminae  continuous  over  the  ante- 
rior false  apex.  Girdle  (fig.  61)  tough  ;  black,  leathery,  hardly 
sinuated  behind,  smooth,  with  a  few  bristles  at  the  sutures  and 
around  the  margin. 

Length  60,  breadth  40  mill. ;  divergence  110°. 

New  Zealand  (Mus.  Cum.,  no.  2.) 

This  very  fine  but  unsculptured  species  was  marked  as  new  in  Dr. 
Gould's  collection,  but  not  described  by  him.  It  is  abnormal  in  the 
nearly  smooth  aspect  of  the  tough  girdle,  in  which  however  the 
binary  pores  (of  which  five  surround  the  head  valve)  are  distinctly 
marked.  The  shape  of  the  valves  is  nearly  as  in  Mopalia  wosness- 
rnsk'd.  (Cjpr.) 

Professor  Hutton  has  considered  his  Tonicia  corticata  a  synonym 
of  biramosa,  in  his  Manual  of  New  Zealand  Mollusca,  1880 ;  but  the 
description  (copied  below)  would  hardly  lead  me  to  the  same 
conclusion,  although  Hutton's  species  is  undoubtedly  a  Plaxiphora* 
In  sculpture  it  must  resemble  P.  terminalis. 

Tonicia  corticata.  Oval ;  margin  naked  ;  valves  much  depressed  ; 
posterior  margins  slightly  concave  ;  lateral  areas  bounded  on  each 
side  by  a  flatly  nodulose  ridge,  the  space  between  being  obliquely 
striated,  the  striae  running  outward  and  backward ;  median  areas 
rugose,  without  either  distinct  lines  or  granules.  Length  1*25, 
breadth  1'13  inch.  Color:  margin  black  when  dry;  valves  grey; 
inside  white,  covered  over  with  white,  coralline  growth  and  small 
marine  algse.  Founded  on  a  specimen  in  the  Colonial  Museum, 
locality  not  stated.  (Hutton,  in  Trans.  N.  Z.  Inst.  iv,  p.  180,  May, 
1872.) 

P.  SIMPLEX  Carpenter.     PI.  67,  figs.  43,  44,  45,  46. 

Shell  similar  to  P.  modesta,  but  more  elevated,  longer ;  valves 
rude,  maculated  with  brown-purple;  dorsal  ridge  rounded;  mucro 
posterior,  flattened ;  lateral  areas  scarcely  defined  ;  valves  rounded, 


i-i  \\M-HMI;  L 

with  larjr  -iitures.       Entire  .-m  th,   L'«'n<Tallv   en. did.  .~ul>- 

spoiiL,ry.      Interior;    j.n>t.  rior    valve    with     a     Hindu  ah-iy     ••!<• 
insertion-plate,  moderately  Miniated  behind.      Anterior  valv    v.itli  *, 
median  valves  1  slit;  teeth  acute,  scarcely  thicken,  d  at  the  .-d^es  of 

the  slits.      Kave>  short,  sj gy.     Sinus  very  narrow,  -niooth,  straii'lit. 

Girdle  spongy,  having  very  close,  small  hairlrts,  and  loiiLr<'i 
hairs  scattered  and  at  the  sutures.     (Q?r.) 

Length  1-35,  l>readth  '7  inch,  divergence  120°. 

Var. :  length  1*1,  breadth  •<;.">  inch,  divergence  100°. 

Tristan  Inland,  Tristan  da  Cunha,  on  the  shore,  and  off  Nighten- 
gale Island,  Tristan  da,  Cunha,  100-150  fms.  ('Challenger.') 

Euplaciphora  simplex  CPU.,  J/N. —  P/axiphora  simplex  CPR.,  in 
Haddon's  Report  on  the  Polyplacophora  of  the  Challenger  Expedi- 
tion, p.  33.  Also  described  by  HADDON,  I.e.,  p.  34,  t.  3,  f.  I-'!, 
13a-c. 

This  species  I  have  not  seen.  The  P.  modesta  alluded  to  by  Car- 
penter is  a  form  of  P.  petholata. 

Haddon  describes  P.  simplex  as  follows  : 

Shell  smooth,  simply  marked  with  line  of  growth,  flat  sides  meet- 
ing at  a  variable  angle.  Anterior  valve  small,  surface  smooth. 
Under  surface  with  eight  slits,  teeth  fairly  long,  smooth  and  sharp ; 
eaves  short.  Intermediate  valve :  Central  area ;  smooth,  flat. 
Lateral  areas  inconspicuous,  with  two  or  three  very  faint  radiating 
ridges.  Under  surface  with  a  median  horizontal  rib-like  swelling ; 
sutural  laminae  broad,  but  not  deep  ;  jugal  sinus  wide  and  shallow ; 
one  lateral  slit ;  eaves  short.  Posterior  valve  very  small  and  flat, 
greatly  corroded;  umbo  apparently  flat  and  terminal;  posterior 
border  thickened.  Under  surface :  sutural  laminae  as  in  intermediate 
valves,  but  the  jugal  sinus  is  comparatively  narrow  and  deep  ;  slits 
and  teeth  absent ;  posterior  border  much  swollen. 

Girdle  very  thick  and  fleshy,  upper  surface  having  a  spongy 
appearance,  owing  to  being  beset  with  very  short  horny  spines, 
which  are  scarcely  raised  above  the  surface;  there  are  tufts  of  longer 
spines,  three  to  nine  in  each  tuft,  opposite  the  sutures  of  the  valves; 
these  have  no  definite  position  round  the  anterior  valve.  Situated 
outside  these  are  numerous  scattered  similar  tufts,  usually  somewhat 
smaller  in  size,  which  pass  into  an  imperfect  peripheral  fringe  of 
spines,  (pi.  67,  figs.  44,  46).  Color:  all  the  valves  of  a  uniform 
dark  brown,  with  a  pale  (lilac)  narrow  triangular  band  along  the 

21 


322  PLAXIPHORA. 

juiriim  of  the  intermediate  valves  (and  anterior  area  of  the  posterior 
valve).  Under  surface  of  all  the  valves  of  a  bluish-green  color ; 
lamina?  of  insertion  paler.  Girdle,  upper  surface  dark  brown  ; 
under  surface  dusky  orange. 

Length  40,  breadth  25,  height  10  mill. ;  angle  of  divergence  125° 
to  135°  (two  specimens  from  100  to  150  fathoms.) 

Length  25  to  35,  breadth  14  to  17,  height  8  to  9  mill. ;  angle  90° 
to  110°  (two  shore  specimens.) 

Group  of  P.  wahlbergi. 

No  sculpture  except  some  concentric  lines;  sinus  deep,  dentic- 
ulate ;  girdle  without  sutural  tufts. 

P.  WAHLBERGI  Krauss.     PI.  55,  figs.  17,  18. 

Shell  ovate-oblong,  slightly  convex  ;  brown  with  a  chestnut-brown 
median  band  and  two  yellowish  longitudinal  bands.  Concentrically 
sulcate.  Interior  white,  brownish-violet  in  the  middle.  Anterior 
valve  semilunar  ;  posterior  valve  subtriangular,  depressed  ;  inter- 
mediate valves  subreniform,  having  distant  concentric  grooves  on 
the  front  part  of  the  central  areas,  and  on  the  lateral  areas.  Girdle 
brown,  leathery,  velvety.  Length  15,  breadth  9  lines. 

This  species  has  rather  thick,  little  convex  valves,  rounded  on 
their  outer  ends,  and  having  the  older  or  posterior  half  of  each 
eroded,  and  deprived  of  color  and  sculpture.  Lateral  areas  not 
differentiated.  The  forward  part  and  the  sides  of  each  valve  have 
6  or  7  separated,  sometimes  finely  granulated  furrows,  parallel  with 
the  margins.  The  posterior  margin  is  eroded,  probably  beaked  in 
the  middle.  The  insertion-plates  are  narrow,  roughened  outside. 
Anterior  valve  excavated  behind,  having  8  slits.  Posterior  valve 
lacking  teeth.  The  valves  have  in  the  middle  a  chestnut-brown 
shining  band,  2  mill,  wide,  on  each  side  of  which  a  yellow  streak  of 
greater  or  lesser  width  generally  lies ;  but  usually  they  are  eroded 
and  gray.  (Krauss.) 

Table  Bay,  Cape  of  Good  Hope. 

Chiton  wahlbergi  KRAUSS,  Die  Sudafrik.  Moll.,  p.  36,  t.  3,  f.  1 
(1848). — Eupladphora  wahlbergi  CPR.,  MS. 

May  be  known  by  the  separated  concentric  grooves  of  lateral  and 
central  areas,  parallel  with  the  valve-margins,  and  also  by  the  sinus, 
which  is  deep,  narrow  and  denticulate,  the  last  being  an  unusual 
character  in  this  genus.  The  girdle  has  irregular  setae. 


I'l.  AMPHORA. 


Shell  somewhat  sculptured.  (iinlh-  covered  with  rri-p  hair-,  not 
forming  bunches  at  tin-  .-mures,  nor  having  pores  there. 

P.  PETHOLATA  Bowerby,     1M.  68,  figs.  <L'.  68,  ''.i  87, 

Shell  elliptical  or  oblong,  rather  depressed,  the  dorsal  angle 
rounded  but  side-slopes  rather  straight.  Surf  ace  finely  corrugated  at 
the  nitl'*,  nearly  smooth  in  tin  mi>l<lle.  Color  black  or  blue-black, 
with  pink,  creamy  or  greenish-white  angular  markings  at  the  sides, 
and  a  wide  triangle  of  the  same  light  tint  on  the  ridge  of  each  valve, 
generally  enclosing  a  dark,  ill-defined  dorsal  stripe. 

The  median  valves  are  slightly  beaked.  Lateral  areas  hardly 
raised,  defined  by  a  narrow,  inconspicuous  and  slightly  cum--! 
diagonal  riblet,  the  surface  finely  corrugated  in  zig-zag  or  vermic- 
ulate  pattern.  Central  areas  corrugated  zigzagly  at  the  sides,  in  front 
of  the  diagonal  ril>,  th>-  corrugation  becoming  fun.  r  toward  the  middle, 
and  giving  place  to  a  microscopic  pattern  resembling  a  dense  punctula- 
tion  united  with  a  minute  zigzag  or  vermiculate  wrinkling.  Anterior 
valve  having  about  9  narrow  radiating  riblets,  the  intervals  densely 
and  finely  zigzag-punctate.  Posterior  valve  depressed,  wide  and 
short,  the  mucro  at  the  posterior  edge,  slightly  acute  and  a  little 
elevated  ;  posterior  area  of  the  valve  very  narrow,  ill-defined. 

Interior  dark  blue-green.  Sinus  deep,  uide,  angular,  its  edge  light 
brown  and  very  spongy.  Anterior  valve  having  8  slits,  correspond- 
ing to  external  riblets,  central  valves  1  slit  ;  the  teeth  acute,  some- 
what thickened  at  the  edges  of  the  slits.  Posterior  valve  having  a 
rather  blunt,  smooth  insertion  plate,  interrupted  by  a  shallow  sinus 
in  the  middle  behind.  Eaves  very  narrow,  spongy. 

Girdle  rather  wide,  black-brown  and  brown  alternately,  rather 
densely  clothed  with  corneous  or  dark  brown  bristles,  large  and 
small,  not  in  the  least  arranged  in  series  or  issuing  from  sutural 
pores. 

Length  40,  breadth  27  mill.;  divergence  125°. 

Length  32,  breadth  18  mill.  ;  divergence  130°. 

Length  45,  breadth  25  mill. 

Australia  (Sowb.)  ;   Tasmania  (Cuming.) 

Chiton  petholatiis  SOWB.,  Mag.  of  Nat.  Hist.  New  Series,  iv,  p. 
289  (May,  1840)  ;  Conchol.  Illustr.,  f.  b'4,  65,  and  var.  porphi/ri,'*, 
f.  59.  —  REEVE,  Conch.  Icon.,  f.  74.  —  fctijilm'ijJtnra  petholata  CPR., 
MS.  Not  Plaxiphora  petholata  ANGAS,  P.  Z.  S.  1865,  p.  187  and 


324  r  i.  AMPHORA. 


1867,  p.  224.—  Eitptadpl'ora  modesta  CPR.,  MS. 

The  sinus  is  squared,  and  the  internal  layer  is  bevelled  off  expos- 
ing the.  very  porous  outer  layer  as  in  Nuttallina.  Back  of  this 
porous  area,  the  width  of  which  varies,  the  surface  shows  transverse 
cuts  or  puncture-slits.  The  hairs  of  the  girdle  show  no  trace  what- 
ever of  arrangement  in  tufts  or  pores.  The  exterior  is  finely  sculpt- 
ured with  zigzag  wrinkles,  and  the  diagonal  riblets  on  each  valve, 
as  well  as  the  radii  on  the  head  valve,  may  be  either  nearly  smooth 
or  closely  granose.  The  pattern  of  coloring  is  characteristic-  but 
still  quite  variable. 

Var.  CONSPERSA  Adams  &  Angas. 

Shell  oval,  little  elevated,  with  obtuse  dorsal  ridge.  Ashy,  with 
a  few  scattered  clouds  of  dark  and  olivaceous. 

Valves  squared,  thin  ;  apices  not  conspicuous,  jugal  areas  marked 
off  by  slight  indentations  which  are  slightly  divergent;  but  other- 
wise finely  sculptured  like  the  rest  of  the  middle  part  of  the  central 
areas  ;  pleura  having  about  20  irregularly  roughened  line  on  each 
side,  the  line  mainly  forming  right  angles  with  the  diagonal  rib,  but 
branching  and  minutely  undulating  ;  becoming  very  fine  toward  and 
upon  the  jugum  ;  interstices  very  small.  Lateral  areas  with  the 
diagonal  rib  much  elevated,  rendered  nodulous  by  the  wrinkles  pass- 
ing over  it  ;  the  same  sculpture  extending  across  the  lateral  areas 
and  becoming  more  nodulous  at  the  suture.  Anterior  valve  having 
8  ribs,  besides  those  at  the  sutures.  Posterior  valve  having  the 
mucro  at  the  posterior  fourth,  and  with  two  diagonal  ribs. 

Interior  :  anterior  valve  having  8  slits,  median  valves  1  slit,  corre- 
sponding to  the  external  ribs  ;  the  teeth  slightly  thickened  at  the 
edges  of  the  slits.  The  posterior  valve  has  well  developed,  sharp 
insertion-plates  on  each  side. 

Girdle  pale  brown,  maculated  with  black-brown  ;  bearing  fine, 
sparsely  scattered  soft  corneous  hairs. 

Length  21-22,  breadth  12-14  mill.,  divergence  117°. 

Port  Lincoln,  South  Australia,  under  rocks  (Angas.) 

Chcetopleura  conspersa  AD.  &  ANO.,  P.  Z.  S.  1864,  p.  193.  — 
ANGAS,  P.  Z.  S.  1865,  p.  ISl.—l'laciphora  conspersa  CPR.,  J/\ 

I  have  seen  no  specimens  of  this  form,  which  Carpenter  believed 
to  be  a  variety  of  P.  petholata.  The  above  description  is  from  Car- 
penter's MS.,  and  was  drawn  from  Angas'  type. 


i-i  AXii-noi:  v. 
P.  CAI:I-I  MI  to    lla.l.lon.      I'l.  o7,  Bgl  8 

Shell  smooth,  the  lidef  meeting  al  an  angli  .      Ant- 

valve  with  riirht  radiating  ridges,  not  counting  the  swollen  po-t 
Itonlrrs.     Numerous  n.n.vnt  ri<-  miii..r  ridges  cause  these  ridges  to  be 
rugose.     Under  iUrfftOQ  \\ith  nine  slits,  two  1  »•  -ing  very  close  toget 
eaves  sliort. 

Intermediate  valves:  central  area  smooth,  with  tin.-  linos  of 
growth  ;  no  distinct  keel.  Lateral  areas  prominent,  concentrically 
rugose,  with  a  beaded  ridire  aloiiLr  tlic  anterior  border,  and,  to  a  less 
extent,  along  the  posterior  border.  Under  surface  with  a  median  hori- 
zontal rib-like  swelling;  sutural  lamina  broad,  but  not  deep  ;  ju.iral 
sinus  shallow  ;  one  lateral  slit ;  eaves  short.  Posterior :  valve  anterior 
area  so  large  as  to  reduce  the  posterior  area  to  a  minimum  ;  smooth  ; 
umbo  minute,  nearly  terminal.  Posterior  area  merely  forms  a  con- 
centrically grooved  thickening  of  the  posterior  border  of  the  valve- 
Under  surface  :  sutural  lamina?  as  before,  but  the  jugal  sinus  is  com- 
paratively narrow  and  deep ;  slits  and  teeth  absent ;  the  posterior 
border  is  greatly  swollen. 

Girdle  closely  beset  with  very  minute  horny  spines.  The  specimen 
had  been  dried  when  I  received  it,  and  none  of  the  longer  spines, 
characteristic  of  other  species,  are  observable ;  but  I  think  I  can 
discern  traces  of  small  sutural  tufts. 

Color :  anterior  valve  with  a  median  triangular  area,  with  the 
apex  at  the  umbo,  is  of  a  kind  of  chocolate  color,  which  is  variegated 
with  minute  zigzag  grey  lines ;  the  lateral  spaces  are  of  a  dark  slate 
color.  Intermediate  valves:  central  area:  jugum  pink;  greenish 
toward  the  umbo  when  worn  down.  Pleura  dark  greenish-brown, 
with  irregular  longitudinal  green  bands.  Lateral  areas  madder 
brown,  blotched  with  brown.  Posterior  valve :  anterior  area  resem- 
bling  the  central  areas ;  posterior  border  pinkish.  Under  surface  of 
all  the  valves  pale  bluish  green  ;  lamina?  of  insertion  white.  Girdle 
reddish-brown. 

Length  14,  breadth  9  mill. ;  height  4  mill.     (Haddon.) 

Tristan  da  Cuntm. 

Plaxiphora  carpenteri  HADDON,  Challenger  Rep.  Polyplac.,  p.  34, 
t.  l,f.  8;  t.  3,  f.  8«-</. 

The  sculpture  of  the  shell,  slight  as  it  is,  is  sufficient  to  character- 
ize this  species.  (Haddon.) 

P.  OLAUCA  Quoy  &  Gaimard.     PI.  68,  figs.  68-72. 

Animal  oval,  widened  at  the  sides.      Valves  wide,  rounded,  little 


326  i-i.AxirnoRA. 

elevated,  subtriangular.  uniform  and  smooth  except  toward  the 
anterior  margins  where  they  are  marked  with  three  or  four  mar- 
ginal strije;  they  are  black  toward  the  lateral  margins,  with  a  tri- 
angle of  the  same  color  in  the  middle,  bordered  with  yellowish  or 
greenish. 

Inside  they  are  of  a  beautiful  emerald  green,  the  sutural  laminae 
being  of  the  same  color  and  separated  by  a  wide  sinus.  The  anterior 
valve  has  its  margin  cut  into  9  smooth  teeth.  Posterior  valve  hav- 
ing a  semi-circular  ridge  in  place  of  the  teeth.  The  valves  taken 
together  form  an  elongated  oval.  All  of  the  intermediate  valves 
have  one  slit  and  two  transverse  striae  on  the  apophyses. 

Girdle  of  a  beautiful  light  green,  covered  with  rigid  but  not  acute 
bristles  of  the  same  color.  (  Q.  &  (?.) 

Length  50,  breadth  37  mill. 

d' Entrecasteaux  Channel,  Tasmania. 

Chiton  glaucns  Q.  &  G.,  Voy.  de  1'Astrol.  Zool.  iii,  p.  376,  t.  74, 
f.  7-11  (1834).  Not  Chiton  glaucus  GRAY,  an  undetermined  species, 
see  p.  172.—lPlaxiphora  ciliata  ANGAS,  P.  Z.  S.  1865,  p.  187,  not 
Chiton  ciliatus  SOWB. 

This  species  is  evidently  allied  to  P.  petholata.  It  is  probably  the 
form  Angas  collected  at  Guichen  Bay,  South  Australia,  and  listed 
as  "  P.  ciliata"  He  found  it  on  rocks  at  low  water,  and  remarks 
that  it  is  the  largest  of  the  South-Australian  Chitonidse. 

Group  of  P.  terminalis. 

Sculpture  stronger  than  in  P.  petholata.  Girdle  generally  with 
more  or  less  distinct  sutural  pores.  Distribution,  New  Zealand. 

P.  TERMINALIS  (Cpr.)  Smith.     PI.  51,  fig.  14. 

Shell  resembling  P.  petholata  in  sculpture,  but  more  elevated, 
longer,  the  mucro  entirely  terminal,  produced.  Dorsal  ridge  striped 
with  white.  Sculpture  much  more  distinct,  consisting  of  irregularly 
zigzag  wrinkles  all  over,  coarser  at  the  sides. 

Interior  having  8  slits  in  the  anterior,  1  in  the  median  valves. 
Posterior  valve  with  subplanate  insertion  plate ;  the  subjugal  area 
punctate,  teeth,  sinus  and  eaves  as  in  7'.  ji'tholata.  Girdle  having 
bunches  of  long  horny  hairs  at  the  sutures  and  around  the  margin, 
elsewhere  smoother. 

Length  25,  breadth  12*  mill. ;  divergence  120°.     (Cpr.) 

New  Zealand  (Cuming.) 


PLAXIPHOHA.  327 

ri<t.rii>hor«  fernt  in<i/i.<  (  Vi:..  .)/>'.  in  M  IH.  (  'inning. —  f'liifnn  (  Ttaxi- 
l»horn')  trrminn/i*  K.  A.  SMITH,  \'.,y.  Kn-biis  and  Terror,  Moll.,  p.  4, 
t.  1,  f.  13  (1874).—  riajcljJiom  t'TminnIi*  Smith,  HUTK-.V,  Man.  N. 
/.  Moll.  1880,  p.  116  (reprinted  from  Smith.) 

Smith  lias  described  this  species  in  detail,  as  follows:  "Shell 
elongately  »>\ate,  rather  elevated,  roundly  angled  along  the  top  of 
the  valves,  black  or  bluish-black,  with  a  white  wedge-shaped  stripe 
with  a  black  one  within  it  down  the  centre  of  the  valves,  forming  a 
continuous  white  stripe  divided  by  the  black  one  along  the  center  of 
the  shell,  in  some  specimens  with  a  few  short  white  dashes  diverg- 
ing from  the  radiating  ridges.  The  intermediate  valves  mucronated, 
bisected  on  each  side  by  one  raised  radiating  rib,  the  posterior  mar- 
gins sinuated  and  thickened  by  coarse  concentric  lamellae ;  the 
entire  surface  is  covered  with  minute  striate-wrinkiing,  those  near 
the  ridge  being  coarser  than  the  rest  and  radiating  from  it  like  the 
webs  from  the  shaft  of  a  feather.  The  posterior  terminal  valve  has 
the  mucro  quite  terminal.  The  anterior  valve  radiately  eight-ribbed 
(at  times  one  or  two  additional  minor  ones  are  present)  with  diverging 
oblique  striations  on  each  side  of  them.  Interior  of  valves  greenish- 
blue  ;  valve  lobes  whitish,  the  sinus  between  them  deep ;  the  hairs 
or  bristles  on  the  mantle-margin  are  short,  few  and  horny,  those 
arising  from  the  nine  pores  being  thicker  than  the  rest. 

"  Largest  specimen  (in  a  contracted  state)  42  mill,  long ;  width  of 
valves,  20  mill. ;  an  average  specimen,  length  25  mill.;  width  11 
mill. 

New  Zealand  (Col.  Bolton  and  Capt.  Stokes.) 

"  Terminalis  "  appears  to  be  but  a  manscript  name  attached  to 
some  specimens  in  the  Cumingian  collection.  As  I  understand  that 
Dr.  P.  P.  Carpenter  is  engaged  on  a  work  on  Chitonidcel  retain  the 
characteristic  name  he  imposes.  The  central  white  stripe  with  the 
black  one  within  it  appears  to  be  very  constant." 

Carpenter  gave  the  varietal  name  zigzag,  (in  MS.)  to  specimens  in 
the  Cuming  collection  (no.  31)  having  stronger  sculpture,  one  more 
anterior  riblet,  etc.  It  seems  to  be,  merely  an  individual  variation. 

P.  EXCURVATA  Carpenter,  n.  sp. 

Shell  elongated,  elevated,  the  dorsal  ridge  rounded,  valves  angled 
at  the  sides,  obtusely  beaked,  the  sutures  indented.  Irregularly 
maculated  with  coppery  green  and  black. 

Lateral  areas  defined  by  an  obtuse  curved  rib ;  toward  the  rib  on 


328  PLAXIPHORA. 

each  side  closely  concentrically  sulculate.  Anterior  valve  having 
about  7  or  8  ribs,  sometimes  with  some  intercalated  subobsolete 
riblets.  Posterior  valve  small,  the  mucro  subposterior,  swollen. 

Interior  blue.  Anterior  valve  having  7-8,  median  valves  1  slit; 
teeth  long,  acute,  scarcely  thickened  at  edges  of  the  slits.  Posterior 
valve  having  an  obtuse  insertion  plate,  a  little  sinuated  in  the  middle 
behind.  Sinus  broad,  straight,  spongy. 

Girdle  wide,  thin,  hardly  sinuated  behind,  tessellated  with  brown 
and  ashy,  beset  all  over  with  sparse,  delicate,  short  setae,  longer  at 
Ihe  sutures. 

Length  70,  breadth  39  mill.;  divergence  about  110°. 

Australia?  (Haines  Coll.,  and  Coll.  McGill  University,  Mon- 
treal.) . 

Euplaciphora  excurvata  CPR.,  MS. 

This  shell  has  a  general  external  resemblance  in  size  and  shape  to 
P.  cuprea,  from  which  it  is  known  at  once  by  the  color  and  sculpture 
outside,  by  having  no  posterior  slit  in  the  girdle,  and  inside  by  the 
smoothness  and  sharpness  of  the  insertion-plates.  It  also  resembles 
P.  superba,  but  is  entirely  destitute  of  sutural  pores. 

P.  CJKLATA  Reeve.    PI.  58,  figs.  21,  22. 

Shell  oblong-ovate,  somewhat  attenuated  anteriorly,  terminal 
valves  (the  posterior  of  which  is  small  and  slanting)  and  lateral 
areas  of  the  rest  broad-ribbed  and  neatly  carved  with  close-set  waved 
lamina? ;  central  areas  very  minutely  reticulated.  Beautifully  orna- 
mented with  green  and  pink.  Ligament  horny,  here  and  there 
bristly.  (Reeve.) 

New  Zealand  (Earl,  Cuming.) 

Chiton  ccelatu*  Rv.,  Conch.  Icon.,  t.  17,  f.  101  (1847).— Strepto- 
chiton  cupreiis  CPR.,  MS.,  olim. — ?  Tonicia  zigzag  HUTTON,  Trans. 
N.  Z.  Inst.  iv,  p.  181  (1872.) 

The  verdigris  green  and  peculiar  pink  color-pattern  is  character- 
istic and  singularly  beautiful. 

Von  Martens  has  stated  that  Tonicia  zigzag  Hutton  is  a  synonym  of 
"  Acanthopleura "  ccelata  Rv.  (Crit.  Cat.,  p.  49) ;  a  conclusion 
accepted  by  Hutton  (Man.  N.  Z.  Moll.,  p.  115,  1880).  As  in  other 
cases  of  alleged  identity,  the  original  type  of  zigzag  should  be 
re-examined.  Button's  description  is  as  follows : 

Tonicia  zigzag  Hutton.  Oblong;  mantle  slightly  tomentose; 
valves  slightly  flattened  on  each  side,  but  not  keeled;  posterior 


ri. \\irn 

margins  >lopin«r   harkwanU   into    a  point,   rrennlated    on    !. 
anterior   valve  with   !'    radiatim:   rid -.:»•-  >iie  concc-i. 

zig-zag  stria*;  lateral  areas  with  two,  on  <-:i<  I  ulges 

crossed  by  line  zig-zag  stria-  ;    pOtterioi  and  median   ar«-;is  with 
fine  oblique  stria- divrr-m'j-  t'n.ni  the  dorsal  line  out  ward  ami  tor 

Md    by    others    divrririni:   outward    and    buekward    forniing  an 
en-ine  turned  pattern.      Length  88  inch.  ;   breadth  .'51   inch. 

Color,  mantle  white;   vakvs  .irivyisli-blark  with  a  white  -tripe  on 
each  side  of  the  dorsal  line  ;   interior  Lrreenish-Une. 

A  single  specimen  is  in  the  ( 'olonial  Museum,  locality  Dot  st:r 
(Button.) 


The  following  species  probably  belongs  here,  but  I  have  seen  no 
specimen,  and  it  has  not  been  figured. 

CHITON  (CH.ETOPLEURA)  PLUMOSUS  Gould. 

Shell  brown-ashy,  valves  concave  scarcely  beaked  ;  anterior  valve 
ornamented  with  plumose  radiating  line;  posterior  valve  small,  the 
apex  marginal  and  having  a  submarginal  rib  on  each  side.  Central 
area  large,  ornamented  with  divaricating  stria?,  and  lateral  plumosely 
co-united  striae.  Lateral  areas  small,  bounded  by  asutural  rib,  striae 
denticulated,  interspaces  clathrate.  Girdle  broad,  leathery,  furnished 
with  (bristly?)  tubules. 

Length  I'D,  breadth  '75  inch.     (Old.) 

Habit'tt  tnil-n 

Allied  to  C.  ccelatu*  Kv.,  which  is  said  to  be  highly  ornamented 
with  green  and  pink.  (7.  collei  and  C.  mmcosus  G.  belong  to  the 
same  group.  (Old.,  in  Proc.  Bost.  Soc.  Nat.  Hist,  vii,  p.  165.) 

Section  Guildingia  Cpr.,  1893,  n.  sect.     . 

Guildwyia  CPR.,  MS.,  and  in  Dall,  Proc.  U.  S.  Nat.  Mus.  1881, 
pp.  284,  288  (type  G.  obtecta  Cpr.  MS.) 

Shell  and  girdle  like  Plaxiphora,  except  that  the  valves  are  partly 
immersed  by  the  encroachment  of  the  girdle. 

This  section,  like  Fannettia  in  the  genus  Toniria,  rests  upon  a 
character  of  very  little  taxonomic  value ;  but  as  it  is  useful  in  break- 
ing up  a  large  genus  for  convenience  in  identifying,  it  has  been 
retained. 


330  PLAXIPHORA. 

P.  OBTECTA  Carpenter,  n.  sp. 

Shell  large,  broad,  partly  covered.  Valves  smooth,  most  minutely 
punctulate  angulate  in  front ;  sutural  sinus  large,  produced  forward 
over  the  jugum  ;  lateral  areas  scarcely  defined  except  by  an  angle 
at  the  forward  outer  margin  of  the  valves ;  dorsal  ridge  rounded. 
Intense  olivaceous,  paler  on  the  dorsal  ridge.  Mucro  of  posterior 
valve  terminal  hardly  produced. 

Interior :  posterior  valve  with  flattened  insertion-plates.  Anterior 
valve  with  8,  central  valves  1  slit ;  teeth  very  acute,  long,  smooth, 
a  little  thickened  at  the  slit-edges ;  eaves  narrow,  spongy.  Sinus 
deep,  very  obtusely  angular,  with  a  spongy  area.  Sutural  laminae 
long,  separated.  Girdle  very  broad,  sinuated  behind,  with  bundles 
of  about  three  large,  horn-like  hairs  at  the  sutures,  and  having 
smaller  ones  sparsely  scattered  all  over  more  or  less  closely.  (  Opr.} 

Length  50,  breadth  32  mill.;  divergence  120.° 

New  Zealand  (Mus.  Cum.,  no.  45.) 

This  very  interesting  shell  differs  from  the  typical  Plaxiphorw  as 
Fanneltia  does  from  Tonicia.  It  is,  however,  simply  an  exaggera- 
tion of  P.  terminalis. 

Section  Fremblya  H.  Adams,  1866. 

Frembleya  H.  AD.,  P.  Z.  S.  1866,  p.  445.  Type  F.  egregia  H. 
AD.— Fremblya  CPU.,  MS.  and  in  Proc.  U.  S.  Nat.  Mus.  1881,  p.  284. 
— Streptochiton  CPR.,  MS.  olim. 

Shell  and  girdle  like  Plaxiphora  except  that  the  former  is  short  and 
broad,  the  tail  valve  very  much  reduced  in  size,  strongly  arched 
upward  in  the  middle  behind.  Slits  in  intermediate  valves  poste- 
riorly situated.  Girdle  having  more  or  less  obvious  sutural  pores. 

The  sculpture  of  these  forms  is  like  that  of  the  more  elaborately 
carved  Plaxiphoras  of  the  same  regions;  but  the  considerable 
modification  in  the  general  form  of  the  tail  valve  may  be  held  to  be 
sufficient  ground  for  the  retention  of  Adams'  generic  name  in  a  sec- 
tional sense.  The  organization  throughout  is  otherwise  very  similar 
to  that  of  Plaxiphora.  Two  species  only  are  known  :  P.  egrcgia,  in 
which  the  shell  is  of  a  peculiar  cg.ir  shape,  wider  behind  the  middle, 
and  the  insertion  plates  are  much  thickened  outside  at  the  edges  of 
the  slits,  and  P.  ovata,  in  which  the  shell  is  widest  at  the  fourth 
valve,  rapidly  narrowing  toward  both  ends. 

The  following  description  of  his  new  genus  is  given  by  H.  Adams : 


i.  \  \  i 


/  •       ,  jni.  nov.      Testa  ovali-,  convexa.      Valv:i-   tran.-\- 

cariiiata1;  apex  p..Mrrioris  valva-  terminal!-,  produeta,  : 
Limlms  anirii>tiis,  posticr  H-sii-.  srti-  conn-is  den-e  ol».-itu-.  The 
covering  of  the  mantle,  the  form  of  the  visible  portions  of  the  valves, 
and  the  peculiarity  ot'tlie  terminal  valve,  render  thi-  ftpecfol  distinct 
from  any  form  of  Chitonidrc  yet  descril.ed.  It  lias  the  appearance 
ofa7,"nm  with  the  mantle  covered  with  long  bristles  instead  of 
imbricate  scales." 

There  seems  to  be  no  reasonable  objection  to  the  correction  of  the 
etymology  of  Frembly's  name,  which  in  H.  Adams'  article  was 
incorrectly  spelled  through  inadvertence  or  typographical  error. 

P.  EGREGIA  H.  Adams.     PI.  65,  figs.  80,  81,  82. 

Shell  ovate,  a  little  narrower  in  front,  green-brown,  paler  at  the 
sides.  Anterior  valve  radially  ribbed,  the  ribs  pustulose,  interstices 
obliquely  lirate  ;  posterior  valve  and  median  valves  subcarinate,  the 
dorsal  areas  densely  longitudinally  lirate;  lateral  areas  radially  rib- 
bed, the  ribs  pustulose.  Girdle  moderate,  furnished  with  short, 
corneous  spicules.  (H.  Ad.) 

Length  15,  breadth  9  mill. 

"Habitat  unknown"  (Ad.);  Newcastle,  Australia  (Dieffenbach, 
teste  Cpr.) 

Frembleya  egregia  H.  AD.,  P.  Z.  S.  1866,  p.  445,  t.  38,  f.  9.— 
Streptochiton  tortuosus  CPR.,  MS.,  olim. 

Of  this  species  I  have  seen  a  single  mutilated  specimen,  no.  36,638 
of  the  Smithsonian  Institution  register.  It  is  yellowish  along  the 
middle  and  at  the  side  margins  of  the  valves,  pale  green  on  the  side- 
slopes.  The  species  differs  from  P.  ovata  in  being  widest  behind  the 
middle.  Carpenter  describes  the  type  as  follows  :  Shell  olivaceous, 
maculated  with  more  or  less  intense  ;  ovate,  broad,  elevated  ;  dorsal 
ridge  rather  acute,  much  elevated,  the  side-slopes  straight.  Valves 
strongly  beaked,  each  one  eroded  in  front  from  the  attrition  of  the 
next  valve  forward.  The  central  areas  have  about  16  line  on  each 
side,  about  equalling  the  interspaces  in  width.  Lateral  areas  elevated, 
bicostate,  the  ribs  strongly  granose,  granules  larger  at  the  sutures, 
intermediate  space  obliquely  costate  or  v-costate.  Anterior 
valve  having  10  radiating  ribs,  the  interstices  sculptured  with 
v-shaped  sulci,  the  v'-s  meeting  over  the  ribs  and  rendering  them 
somewhat  nodulous.  Posterior  valve  with  posterior  elevated  mucro 
and  a  single  posterior  rib  on  each  side  ;  posterior  area  very  narrow 


332  PLAXIPHORA. 

and  smooth.  The  girdle  has  soft  hairs,  and  a  few  larger,  and  there 
is  some  trace  of  pores.  The  posterior  slit  in  the  girdle  mentioned  by 
Adams  seems  to  be  an  accidental  tear ;  H.  Adams  believes  the 
same. 

Length  15,  breadth  10  mill.;  divergence  133°. 

P.  OVATA  Hutton.     PI.  54,  figs.  34-40. 

Shell  short-oval,  very  wide  in  the  middle,  rapidly  narrowing  toward 
the  ends ;  moderately  elevated,  the  dorsal  ridge  carinated,  side  slopes 
slightly  convex.  Surface  lusterless,  sculptured  in  "herring-bone1" 
pattern.  Color  buff  along  the  ridge,  pale  olive-green  on  the  side- 
slopes,  with  a  small  curved  dark  spot  or  two  on  each  valve. 

Median  valves  broadly  v-shaped,  the  apices  of  the  valves  elevated 
and  acute.  Lateral  areas  narrow,  a  little  raised,  the  diagonal  rib 
sculptured  with  a  series  of  closely  super-imposed  v's,  their  apices 
directed  toward  the  beak  of  the  valve,  one  limb  of  each  v  direc- 
ted outward,  curving,  and  forming  the  sculpture  of  the  pleura, 
the  other  limb  forming  an  oblique  corrugation  of  the  lateral  area 
(fig.  40).  Sutural  margin  of  each  lateral  area  obliquely,  coarsely 
granose.  Central  areas  having  a  nearly  smooth  band  along  the 
dorsal  ridge,  and  numerous  slightly  curving  and  diverging  riblets  on 
each  side.  Anterior  valve  small,  its  width  about  that  of  one  side- 
slope  of  the  fourth  valve,  its  apex  elevated  and  slightly  recurved  ; 
surface  having  8  strong  ribs,  besides  those  at  the  sutural  margins, 
the  anterior  ribs  strongest  and  wider  apart;  ribs  nodose,  intervals 
obliquely  corrugated.  Posterior  valve  (figs.  36-39)  small,  forming  an 
extremely  narrow  crescent,  strongly  curved  upward  at  the  acute  pos- 
terior mucro,  the  front  ("  central ")  area  narrow,  concave  ;  viewed 
from  behind  (fig.  37)  it  presents  the  appearance  of  a  wide  inverted 
v. 

Interior  bluish-white.  Sinus  exceedingly  broad,  rounded,  the 
sutural-plates  widely  separated.  Insertion  plates  long,  having  the 
slit  near  the  posterior  edge  of  the  plate.  Anterior  valve  having  8, 
median  valves  1  slit.  Posterior  valve  (fig.  39)  having  a  keel-like 
insertion-plate  without  slits  on  each  side,  and  a  broad  sinus  in  the 
middle  behind. 

Girdle  rather  narrow,  yellowish,  bearing  a  pore-tuft  of  hyaline 
white  bristles  at  each  suture  and  a  fringe  of  bristles  at  the  edge. 

Length  15,  breadth  13  mill.;  divergence  112°. 

Cook  Strait;  Duwdhi,  Xcw  Zealand ;  on  seaweed. 

Acanthochcetes  ovatus  HUTTON,  Trans.  N.  /.  lust,  iv,  p.  182  (1872). 


ri.  \\irii< 

ovotui  Hi  PTCW,  Man.  N.  X.  M"1I.,  p.  177  -1880.) 
This  species  differs  from   /  a  in  contour  Bivalve 

the   widest,    tin-   .-ixth    mueh    n:irrnw.-r.    whilst    in    t 
species  the  fifth  and  sixth  valves  are  as  wide  as  tin-  fourth  :  i 
<»\-er  the  side  teeth  of  ovafa  do  IK.I  ieen  to  l)c  thickened  at  the  edges 
of  the  slits  as  they  an-  in   f///vv//'./.     The  specimen  described  and 
figured  was  sent  by  Professor  Iluttoii. 


ERRATA. 

Page    75,  dele  the  word  ISCHNOCHITON,  in  8th  line. 

Page    97, 1.  CURTISIANUS  is  not  an  Ischnochiton  but  a  Liolophura, 

see  p.  242. 

Page  110,  For  "7.  regulatw"  read  "  J.  rugulatiu." 
Page  133,  "  I.  PUSIO"  is  probably  not  an  Ischnochiton,  but  a  true 

Chiton,  and  it  is  likely  to  prove  identical  with   Chiton 

murrayi  Haddon,  described  on  p.  161. 

Page  151,  line  11,  for  "  indentification"  read  "identification." 
Page  182,  last  line,  remove  "  C.  scytoderma  "  from  the  synonymy 

of  C.  rubicundus. 
Page  191.  The  authority  for  C.  SULCATUS  should  be  "  Wood,"  not 

"  Sowerby." 

Page  204,  line  14,  for  "indentification"  read  "identification." 
Page  206,  fifth  line  from  bottom  ;  the  reference  to  Savijrny  should 

read  "  t.  3,  f.  6,  1-2,"  instead  of"  f.  4." 
Page  329.  "  Chiton  (Acanthopleura')  piceolus"  Shuttlew.,  included 

under  Acanthopleura  granulata  as  a  doubtful  synonym, 

is  probably  referable  to  the  genus  NUTTALLINA,  s.  g. 

Middendorffia,   and   it   should  be  compared  with   JV. 

rlnerea  Poli,  p.  283. 

NOTE. 

The  Index  to  Chitons  will  accompany  the  conclusion  of  the  mono- 
graph, to  be  contained  in  the  next  part  of  the  MANUAL. 


EXPLANATION   OF   PLATES. 


NOTE. — The  drawings  credited  to  Foord,  Smith  and  Emerton  were 
prepared  under  the  supervision  of  Dr.  Carpenter,  and  were  loaned 
by  the  Smithsonian  Institution,  for  reproduction  in  the  MANUAL. 

PLATE  1. 

FIGURE.  PAGE. 

1-13.  Lepidopleurus  benthus  Haddon.     Challenger,     .         .       9 
14-22.  Lepidopleurus  belknapi  Dall.     Challenger,         .         .       7 

PLATE  2. 

23-31.  Lepidopleurus  alveolus  Sars.     Moll.  Arct.  Norv.,  6 

39,  40.  Lepidopleurus  pagenstecheri  Pffr.     Moll.  S.  Georg.,  12 

41,  43-46.  Lepidopleurus  cajetanus  Poli.     Ross  del.,      .  15 

42.  Lepidopleurus  cajetanus  Poli.     Conch.  Icon.,    .         .  15 
47-50.  Lepidopleurus  grauoliratus  Cpr.     Pilsbry  del.,    .  14 
51-53.  Lepidopleurus  granoliratus  Cpr.     Foord  del,      .  14 

PLATE  3. 

54-57.  Lepidopleurus  cancellatus  Sowb.  Moll.  Reg.  Arct.,  .  3 
58.  Lepidopleurus  cancellatus  Sowb.  Ross  del.,  ...  3 
59-63.  Lepidopleurus  arcticus  Sars.  Moll.  Reg.  Arct.,  .  5 
64-66.  Lepidopleurus  asellus  Speng.  Ross  del.,  .  .13 

67-70.  Lepidopleurus  rugatus  Cpr.  Pilsbry  del.,  .  .  .11 
71-79.  Hanleya  hanleyi  Bean.  Moll.  Reg.  Arct.,  .  .  17 

PLATE  4. 

74-77.  Hanleya  hanleyi  var.  abyssorum   Sars.     Moll.   Reg. 

Arct 18 

|78-81.  Lepidopleurus  curvatus  Cpr.  Emerton  del.,  .  .16 
82-84,  85.  Hanleya  mendicaria  M.  &  A.  Emerton  del.,  .  18 
83.  Hanleya  mendicaria  M.  &  A.  Inv.  Mass.,  .  .  .18 

86.  Lepidopleurus  rarinotus  Jeffr.     P.  Z.  S.,  .  See  Appendix. 

87.  Lepidopleurus  catillus  Rv.     Conch.  Icon.,         .         .         .10 

88.  Lepidopleurus  fuliginatus  Ad.  &  Rv.     Conch.  Icon.,         .     10 

PLATE  5. 

89-100.  Hemiarthrum  setulosum  Cpr.    Challenger  Rep.,        .     20 

(334) 


i  \i-i  \-  -  335 

1    :;.    iromiarthnini  srtulosuni  Cpr.     Moll.  >    '  .         .     20 

4-8.  Qemiarthrom  wtolotum  Q>r,     Kmrrton  <!.•!., 

I'I.MI.  •;. 

9-11.  Mirroplax  «^rayi  A«l.  A'  An-.      K.  A.  Smith  del.,  .     21 

12-H).    Ilanli'va  ti-MpHMlis  Dull.      Km.Tton  del.,      .          .          .19 
17,  IS.    II:uilry:itr..picalis  Dall.      '  I5l:.k«-  '  Moll.,    .          .  .      !'.» 

19,  21.  Trachydrrmon  sU-im-nii  I'liV.     Moll.  S.  (ieorg.,  . 
22-24.  Trachydermon  lividus  Mi<ld.     Mai.  Ross.,  .         .     76 

25-27.  Trarhydennon  cincreus  L.     Moll.  Reg.  Arct.,     . 

28.  Trachydermon  cinereus  L.     Ross  del.,      .         .         .         ,    6fl 

29,  30.  Trachyderinoii  cinereus  L.     Pilsbry  del.,    ...     68 
31.  Trachydermon  cinereus  L.     Hist.  Br.  Moll.,     .         .         .68 
32-34.  Trachydermon  allms  L.  (head  and  tail  valves  badly 

drawn).     Emerton  del., 70 

PLATE  7. 

35.  Trachydermon  albus  L.     Moll.  Reg.  Arct.,      .         .  70 

36-38.  Trachydermon  albus  L.     Pilsbry  del.,         .         .  70 

39-45.  Trachydermon  exaratus  Sars.     Moll.  Reg.  Arct,  71 

46-49.  Trachydermon  exaratus  Sars.     Tr.  Conn.  Acad.,  71 

50-56.  Trachydermon  ruber  L.     Moll.  Reg.  Arct.,         .  80 

57.  Trachydermon  cinereus  L.     Pilsbry  del.,          .         .  68 

58.  Trachydermon  cinereus  var.  variegatus  Phil.     Moll.  Sicil.  69 
59-60.  Trachydermon  cinereus  var.  variegatus  Phil.      Moll 

Rouss., 69 

PLATE  8. 

61-65.  Trachydermon  dentiens  Gould.     Pilsbry  del.,      .  .  73 

66-68.  Trachydermon  scrobiculatus  Midd.     Mai.  Ross.,  .  76 

69,  70.  Trachydermon  pusillus  Sowb.     Conch.  Icon.,      .  .  80 

71.  Trachydermon  stramineus  Sowb.     Conch.  111.,  .  .  79 

72,  73.  Trachydermon  virgatus  Rv.     Conch.  Icon.,         .  .  78 
74,  75.  Trachydermon  virescens  Rv.     Conch.  Icon.,       .  .  7s 
76,  77.  Trachydermon  puniceus  Couth.     Expl.  Exped.,  ,  81 
78,  79.  Chsetopleura   cullierti   Rochebr.      Moll.   Cap   Horn, 

[See  Appendix 

80,  82.  Callochiton  fulgetrum  Reeve.     Conch.  Icon.,       .         .     83 

81.  Cal  loch  i  ton  fulgetrum  Reeve.     Cpr.  del.,  .         .         .         .83 
83-85.  Callochiton  lobatus  Cpr.     Emertou  del.,      .         .         .53 

PLATE  9. 

86,  87,  91.  Callochiton  castaneus  Wood.     Conch.  111.,     .  .     52 

88,  89,  90.  Callochiton  castnneus  Wood.     Pilsbry  del.,  .  .     52 

92.  Callochiton  illuminatiis  Rve.     Emerton  del.,    .         .  .51 

93,  94.  Callochiton  illumiuatus  Rve.    Conch.  Icon.,         .  .     51 


336  I  :\1  I  .A  NATION  OF  PLATES. 

95,  96.  Callochiton  lievis  Mont.     Pilsbry  del.,         ...     49 
97,  98.  Callochiton  Irevis  Mont.     Hist.  l*r.  M..11,  •     49 

PLATE  10. 

1,  2.  Callocbiton  platessa  Gld.     U.  S.  Exped.,      ...  49 

3,  4,  5.  Callochiton  platessa  Gld.     Emerton  del.,          .         .  49 

6.  Callochiton  versicolor  Ad.  (^platessa  Gld.).    P.  Z.  S.,     .  50 

7.  Callochiton  crocinus  Rve.  (probably  distinct  from  versi- 

color).    Conch.  Icon., 50 

8.  10-15.  Tonicella  marmorea  Fabr.     Moll.  Reg.  Arct,        .    41 
16-21.  Tonicella  submarmorea  Midd.     Emerton  del.,     .         .42 
22-24.  Tonicella  subnmrmorea  Midd.     Mai.  Ross.,         .         .     42 

PLATE  11. 

25,  27.  Tonicella  lineata  Wood.     Ross  del.,    .         .         .         .42 

26.  Tonicella  lineata  Wood.     Emerton  del.,  .         .         .         .42 
28.  Tonicella  lineata  Wood.     Pilsbry  del.,     .         .         .         .42 
29-31.  Tonicella  sitchensis  Midd.     Mai.  Ross.,       ...     44 
32-34.  Schizoplax  brandti  Midd.     Sib.  Reise,         ...     47 
35-37.  Schizoplax  brandti  Midd.     Emerton  del.,  .         .         .47 
38,  39.  Leptoplax  coarctatus  Sowb.     Emerton  del.,        .         .     25 
40,  41.  Ischnochiton  interstinctus  Gld.     U.  S.  Ex.  Exped.,     .  119 

PLATE  12. 

42.  Chsetopleura  peruviana  Lm.     Ross  del.,   .         .  .  .28 

43-46.  Chsetopleura  peruviana  Lm.     Emerton  del.,  .  .     28 

47.  Chsetopleura  hennahi  Gray.     Conch.  Icon.,      .  .  .29 

48,  49.  Chsetopleura  hennahi  Gray.     Ross  del.,       .  .  .29 

50.  Chsetopleura  parallela  Cpr.     Ross  del.,     .        .  .         .34 

51.  Chaetopleura  columbiensis  Sowb.     Conch.  Illust.,  .         .     34 

52.  Chsetopleura  columbiensis  Sowb.     Conch.  Icon.,  .         .     34 

53.  54.  Chaetopleura  lurida  Sowb.     Conch.  Icon.,   .  .     33 
55,  56.  Chsetopleura  scabriculus  Sowb.   (=lurida).  Conch. 

Ill,  .  ...  .      33,  34 

PLATE  13. 

57,  58.  Chsetopleura  isabellei  Orb.    Voy.  Ame"r.  Me>id,         .     35 

59.  Chsetopleura  janeirensis  Gray.     Conch.  111.,      .         .         .37 

60.  Chsetopleura  janeirensia  Gray.     Pilsbry  del.,    .         .         .37 
61,62.  Chiton  segmentatus  Rv.    Conch.  Icon.(=Chsetopleura 

janeirensis),  ...  ....     37 

63,  64.  Chsetopleura  spinulosa  Gray.    Conch.  Icon.,       .         .     38 
65,  66.  Chsetopleura  dieffenbachi  Rve.  Conch.  Icon., 
67,  68.  Chsetopleura  sowerbyana  Rve.    Conch.  Icon,     .         .     39 
69,  70.  Chsetopleura  gemmea  Cpr.     Emerton  del.,          .         .     31 
71-74.  Chsetopleura  gemmea  Cpr.    Ross  del.,         .         .        .31 


i  \ri.\\  \  i  [OX  Of  i'i  \ 

PLATE  i  i. 

80.  Chaetopleura Dobilis  Rve.    (  ouch.  Icon., 

81.  Cyanoplax  hart  uviri  <  '|>r.     Original,          .  .  .  .45 
82,83.  Cyanoplax  hart  wriri  < '|>r.      Kiin-rton  del.,  .  .  .      1-0 
84,85.  Cyanoplax  bartwegi  Cpr.     Ross  del.,  .  .  .     l."» 
86-81*.   Ischii.,rliit«.n  acrior  Cpr.     Ross  del.,  .  .  .     «:i 

90,  Cyanoplax  hipunrtatus  Sowb.     Conch.  111.,       .         .         .46 

PLATE  15. 

91,  93.  Ischnochiton  conspicuus  Cpr.     Ross  del.,    .         .         .    J63 

92,  96.  Ischnochiton  conspicnus  Cpr.     Piisbry  del.,        .         .     63 
94,  95.  Ischnochiton  conspicuus  Cpr.     Emerton  del.,      .         .     63 

97.  Ischnochiton  conspicuus  var.  solidus  Cpr.     Emerton  del.,     64 

98,  100.  Ischnochiton  magdalenensis  Hds.     Ross  del.,    .         .     62 

PLATE  16. 

1,  2.  Ischnochiton  alatus  Sowb.  Emerton  del.,  .  .  .60 
3,  4.  Ischnochiton  alatus  Sowb.  Piisbry  del.,  .  .  .60 
5.  Ischnochiton  alatus  Sowb.  Ross  del.,  .  .  .60 

6-8.  Ischnochiton  juloides  Ad.  P.  Z.  S.,  ....  55 
9,  10.  Ischnochiton  limaciformis  Sowb.  Ross  del.,  .  .  57 

11,  12.  Chiton  productus   Rv.    (=1.   limaciformis).     Conch. 

Icon 57 

13,  14.  Chiton  sanguineus  Rv.  (=1.  limaciformis).     Conch. 

Icon., 57 

15,  16.  Ischnochiton  limaciformis  Sow.     Conch.  Icon.,   .         .     57 

17,  18.  Ischnochiton  fallax  Cpr.     Emerton  del.,     .         .         .59 

PLATE  17. 

19,  20.  Ischnochiton  floridanus  Pils.     Ross  del.,     .  .  .58 

21,  22.  Ischnochiton  floridanus  Pils.     Piisbry  del.,  .  .     58 

23,  23.  Ischnochiton  purpurascens  Ad.     Ross  del.,  .  .     58 

24.  Ischnochiton  purpurascens  Ad.     Emerton  del.,  .  .     58 
25  26.  Ischnochiton  pectinatus  Sowb.     Ross  del.,    .  .  .64 
27,  28.  Ischnochiton  pectinatus  Sowb.     Emerton  del.,  .  .     64 

29.  Ischnochiton  pectinatus  Sowb.     Piisbry  del.,    .         .         .64 

30.  Chiton  acutiliratus  Rv.  (— I.  pectinatus  Sowb.).      Conch. 

Icon., .  64,  65 

32,  33.  Ischnochiton  viridulus  Couth.     U.  S.  Exped.,     .         .  141 

39.  Chsetopleura  hennahi  Gray.     Piisbry  del.,        .         .         .     29 

PLATE  18. 

35-39.  Ischnochiton  tridentatus  Piisbry.     Piisbry  del.,  .  140 

40.  Ischnochiton  trifidus  Cpr.     Cpr.  del.  (see  appendix),         .  141 
41-46.  Ischnochiton  regulari^  Cpr.     Emerton  del.,         .         .142 

22 


338  EXPLANATION  OF  PLATES. 

47,48.  Ischnochiton  dispar  Sowb.     Conch.  Icon.,  .         .  .111 

4'.),  50.  Ischnochiton  inquinatiu  Rve.     Conch.  Icon.,      .  .     90 

51-55.  Ischuochiton  adamsii  Cpr.     Pilsbry  del.,     .         .  .111 

56,  57,  59.  Ischnochiton  australis  Sow.     Pilsbry  del.,     .  .144 
58.  Ischnochiton  australis  Sow.     Conch.  Icon.,        .         .  .144 

PLATE  19. 

60,  61.  Ischnochiton  tigrinus  Krauss.     Siidafrik.  Moll.,  .  143 
62,  63.  Ischnochiton    tigrinus   var.    unicolor   Pils.     Pilsbry 

del.,       .         .  143,  144 

64-66.  Ischnochiton  hakodadensis  Cpr.     Pilsbry  del.,  .  147 

67.  Ischnochiton  novoehollandiit  Gray.     Pilsbry  del.,     .  .  145 

68.  Ischnochiton  noviehollandite  Gray.     Ross  del.,          .  .  145 

69.  Ischuochitou  novBedollandirc  Gray.    Conch.  Icon.,    .  .  145 
70-74.  Ischnochiton  albrechti  Schrenck.     Amurl.  Moll.,  .  147 

PLATE  20. 

1-4.  Ischnochiton  rissoi  Payr.     Bull.  S.  Mai.  ItaL,       .  .102 
5-7.  Ischnochiton  rissoi  Payr.  (young).     Bull.  S.  Mai.  Ital.,  102 

8-10.  Ischnochiton  rissoi  var.  meneghinii.     Journ.  Conch.,  .  103 

11.  Ischnochiton  yerburyi  Smith.     P.  Z.  S.,   .         .         .  .  101 

12,  3,  14,  15.  Ischnochiton  oniscus  Kr.     Siidaf.  Moll,  .  100 
16,  17.  Ischnochiton  reticulatus  Rv.     Conch.  Icon.,         .  .  101 
18,  19.  Ischnochiton  pertusus  Rv.     Conch.  Icon.,  .         .  .  103 
20.  Ischnochiton  striolatus  Gray.     Conch.  Icon.,    .         .  .  105 
21-24.  Ischnochiton  striolatus  Gray.     Ross  del.,    .         .  .  105 
25,  26.  Ischnochiton  caribreorum  (Cpr.)  Smith  (=1.  striola- 
tus).    J.  Linn.  Soc., 107 

PLATE  21. 

27,  28.  Ischnochiton  pruinosus  Gld.     U.  S.  Expl.  Exped.,  .  109 

29-34.  Ischnochiton  imitator  Smith.     P.  Z.  S.,  116 

35,  38.  Ischnochiton  punctulatissimus  Sowb.     Conch.  111.,  .  115 

36,  37.  Ischnochiton  punctulatissimus  Sowb.     Pilsbry  del.,  .115 

39.  Ischnochiton  interstinctus  Gld.     Pilsbry  del.,            .  .119 

40,  41.  Ischnochiton  papillosus  Ad.     Ross  del.,      ...  .  114 
42-46.  Callistochiton  shuttleworthianus  Pils.     Pilsbry  del.,  .  273 
47,  48.  Ischnochiton  catenulatus  Sowb.     Conch.  Illust.,  .  110 

49.  Ischnochiton  roseus  Sowb.     Conch.  Icon.,          .         .  .113 

50.  Ischnochiton  roseus  Sowb.     Conch.  Illustr.,      .         .  .113 

51.  52.  Ischuochiton  colubrifer  Rve.     Conch.  Icon.,        .  .     95 
•r> •').  Ischnochiton  rugulatus  Sowb.     Beechey's  Voy.,        .  .110 
54-56.  Ischnochiton  rugulatus  Sowb.     Couch  111.,           .  .110 

57.  Ischnochiton  rugulatus  Sowb.    Conch.  Icon.,    .         .  .110 


i.  \I-I\N  \  i  [OH  OF  PLJ 

I'I.M  i:  22. 


58,  [sohnochiton  loDgioymba  Q.  db  Q,     K'"-  del.,         .  .    87 

[•chnochiton  loDgicymba  Q.  <&  G.     A-tn.l..     .        .  .87 

<;o-i;»;.  Isrimorhit.m  longicjmbfl  o.  A  GK     I'iUi.rv  del.,  .    87 

Kshnoohiton  huddoni  I'ik     I'ilsb.-y  del.,  .    88 
68,70,71.  C.  longicrmba  Sow.  (     I.  haddoni  I'ik;.    Conch. 
111..       .                        .                        ... 

69.  C.  loiiLrirymhu  live.  (=1.  haddoni  I'ils.).     Conch.  Icon.,  . 

74.  Ischnochiton  divi-ri^'ns  Rve.     Pilsbry  del.,       .         .  .90 
75,76.  Ischnochiton  divergens  Rve.     Ross  del., 

77.  Ischnochiton  divergens  Rve.     Conch.  Icon.,     .         .  .90 

PLATE  23. 

78.  80.  Ischnochiton  fruticosus  Old.     U.  S.  Ex.  Exped.,  .     91 

79.  Ischnochiton  fruticosus  Gld.     Pilsbry  del.,       .         .  .91 
81,  82.  Ischnochiton  contractus  Rve.     Conch.  Icon.,       .  .     93 
83,  84.  Ischnochiton  decussatus  Rve.  (=contractus).     Conch. 

Icon..    .........  93,  94 

85.  Ischnochiton  exiguus  Sowb.     Conch.  Illustr.,    .         .  .98 

86.  Ischnochiton  exiguus  Sowb.     Conch.  Icon.,       .         .  .98 

87.  88.  Ischnochiton  castus  (—contractus).     Conch.  Icon.,  93,  94 
89,  90.  Ischnochiton  sculptus  Sowb.     Conch.  Illustr.      .  .     92 
91.  Ischnochiton  pallidus  Rve.     Conch.  Icon.,        .         .  .89 
92,93.  Ischnochiton  petaloides  Gld.     U.  S.  Exped.,       .  .118 
94,  95.  Ischnochiton  carinulatus  Rv.     Conch.  Icon.,       .  .     96 
96,  97.  Ischnochitou  pallidulus  Rv.     Couch.  Icon.,         .  .     95 

PLATE  24. 

98,  99.  Ischnochiton  crispus  Rve.     Conch.  Icon.,    .         .  .89 

100,  1-4.  Ischnochiton  ustulatus  Rve.     Emerton  del.,      .  .     96 

o.  Chiton  granulosus  Frembly.     Zool.  Journ.,       .         Appendix. 

6.  Liolophura  curtisiana  Smith.     '  Alert  '  Zool.,    .         .  .  '24- 

7,  8.  Ischnochiton  adelaidensis  Rve.     Conch.  Icon.,      .  .136 
9,  10.  Ischnochiton  muscarius  Rve.     Conch.  Icon.,       .  .132 

11,  12.  Ischnochiton  ustulatus  Rve.     Conch.  Icon.,         .  .     96 
13-15.  Ischnochiton  tessellatus  Q.  &  G.     Astrol., 

16,  17.  Ischnochiton  arbutum  Rve.     Conch.  Icon.,          .  .139 

18,  19.  Ischnochiton  milleri  Gray.     Conch.  Icon.,  .         .  .  137 
20-22.  Ischnochiton    cariosus    Cpr.    var.    subcariosus    Pils. 

Pilsbry  del.,           .......  65,  67 

23.  Ischnochiton  cariosus  Cpr.  typical.     Emertou  del.,    .  .     65 

PLATE  25. 

1-10.  Ischnochiton  dalli  Haddon.     Chall.  Rep  .....  133 

11-19.  Ischnochiton  dorsuosus  Haddon.     Chall.  Rep.,      .  .  135 


340  i:\l-LANATION  OF  PLATES. 

PLATE  26. 

20,  21.  Ischnochiton  mertensii  Midd.     Ross  del.,    .  .  .  125 

22,  24-26.  Ischnochiton  mertensii  Midd.     Pilsbry  del.,  .  125 

23.  Ischnochiton  mertensii  Midd.     Emerton,          .  .  .125 
27.  Ischnochitou  cooperi  Cpr.     Ross  del.,      .        .  .  .127 
28-30.  Ischnochiton  cooperi  Cpr.     Pilsbry  del.,     .  .  .  127 
31-33.  Ischnochiton  clathratus  Rve.     Pilsbry  del,  .  .  128 
34.  Ischnochiton  clathratus  Rve.     Emerton  del.,    .  .  .  128 

PLATE  27. 

35-39.  Ischnochiton  lindholmi  Schr.     Amurl.  Moll.,      .         .     85 
40-43.  Ischnochiton    cyaneopunctatus    Kr.    (=lentiginosus 

Sowb.)    8uda£Moll., 135 

44.  Ischnochiton  lentiginosus  Sowb.     Conch.  111.,    .         .         .  135 

45,  46.  Ischuochiton  versicolor  Sowb.     Conch.  Illustr.,  Appendix. 
47,  48.  Ischnochiton  pulcherrimus  Sowb.     Conch.  Icon.,         .  130 

49.  Ischnochiton  constant!  Velain.     Arch.  Z.  Expe>.,  Appendix. 

50.  Ischnochiton  coreanicus  A.  &  R.     Conch.  Icon.,  .         .129 

51.  Ischnochiton  bergoti  Velain.     Arch.  Z.  Expe*r.,  Appendix. 
52-54.  Ischnochiton  inca  Orb.     Voy.  Amer.  M£rid.,  Appendix. 

PLATE  28. 

1-4.  Chiton  sulcatus  Wood.     Ross,  del.,       .        .         .         .191 
5-8.  Chiton  goodalli  Brod.     Ross,  del.,         .         .         .         .191 

PLATE  29. 

9.  Chiton  goodalli  Brod.  Conch.  Icon.,  ....  191 
10.  Chiton  barnesi  Sowb.  Conch  Icon.,  ....  190 
11,12.  Chiton  barnesi  Sowb.  Pilsbry  del.,  ,  .  .190 

13,  14.  Chiton   (?)   dimorphus   Rochebr.     Miss.  Cap   Horn. 

(See  appendix). 
15-21.  Chiton  murrayi  Haddon  (?— C.  pusio  Sowb.,  p.  133). 

Chall.  Rep.,  .  .161 

PLATE  30. 

23.  Chiton  magnificus  Desh.     Ross  del.,         .         .         .         .160 

24.  Chiton  magnificus  Desh.     Emerton  del.,  .         .         .         .160 

25.  Chiton  stokesii  Desh.     Conch.  Icon.,         ....  165 
2(>.  Chiton  stokesii  Desh.     Original, 165 

27.  Chiton  granosus  Frenab.     Pilsbry  del.,     .         .         .         .167 

28.  Chiton  granosus  Fremb.     Zool.  Journ.,    ....  167 

29.  31.  Chiton  cumingi  Fremb.     Conch.  Icon.,        .         .         .164 

30.  Chiton  cumingi  Fremb.     Ross  del.,  ....  164 


i  MM.  \N  \  i  IMS  .,i  i-i  •  :;il 

PLATE  81, 

!.   Chiton  PUftidU  D.'-h.      Moll.  K.'iiri.,    .                               .  186 
8,   (  'liiton  lyratns  Sowb.      C-.nch.  Iron 184 

37, 38.  Chiton  anguttiooftatai  Q.     v  -1 187 

:;•.»,  in.  Chiton  mftorititnafl  Voy,     Voy.  Astro]..     .  .  188 

II,  I'J.  Chiton  oaptMisis  Gray  (— nigroviivns  I>lv.).     Conch. 
Icon.,     ......  . 

43.  Chiton  cymbiola  So\\l>.  (      tulipa  (,).).     Conch.  Icon., 

44,  46, 47.  Chiton  tulip*  Quoy.     KOSH  del.,   .        .        .        .185 

46.  Chiton  tulipa  Quov.    Voy.  Astrol. 185 

48,  49.  Chiton  cymbiola  Sowb.  (^tulipa  Q.)          ...  185 

PLATE  32. 

50.  Chiton  patulus  Brod.  (—stokesii  Brod.).     Conch.  Icon.,      !•;."> 
51-52.  Chiton  stokesii  Brod.     Pilsbry  del.,     .         .         .         .  I'M 

53.  Chiton    stokesii  Brod.    (1  sq.  mm.  of  girdle  indicated), 

I'.lsbrydel., 165 

54.  Chiton  virgulatus  Sowb.     Conch.  Icon.,    ....   IHO 

55.  56.  Chiton  virgulatus  Sowb.     Pilsbry  del.,        .         .         .  166 

57.  Chiton  albolineatus  Sowb.     Conch.  Illustr.,      .         .         .  160 

PLATE  33. 

58,  59,  60.  Chiton  tuberculatus  L.     Ross  del.,         .         .         .153 

61.  Chiton  tuberculatus  var.  assimilis  Rv.     Conch.  Icon.,        .  !">"> 

62.  Chiton  tuberculatus  var.  assimilis  Rv.     Ross  del.,    .         .  155 

63.  Chiton  tuberculatus  var.  assimilis  form  ater.       Ross  del.,  155 

64.  Chiton   foveolatus  Sowb.)    (•— viridis   Spengl.).      Conch. 

Icon.,     .         .         . 156 

65.  Chiton  viridis  Spengl.     Ross  del., !•">»> 

66  67.  Chiton  viridis  Spengl.     Pilsbry  del.,    ....  156 

PLATE  34. 

68.  Chiton  lievigatus   var.  arfciculatus  Sowb.,    ventral  view. 

Emerton  del., 1">9 

69.  Chiton  laevigatus  var.  articulatus  Sowb.     Conch.  Icon.,     .  159 

70.  Chiton  Isevigatus  var.  articulatus  Sowb.  interior.     Pilsbry 

del.,       .        .         .         .                  .         .         .  .  .  169 

71.  Chiton  Isevigatus  Sowb.,  typical.     Conch.  Icon.,  .  .  159 

72.  74.  Chiton  marmoratus  Gmel.     Ross  del.,         .  .  .158 

73.  Chiton  marmoratus  Gmel.     Conch.  Illustr.,      .  .  .  l.~>s 

75.  Chiton  marmoratus  Gmel.,  interior.     Pilsbry  del.,    .         .  1">* 

76.  Chiton  marmoratus  Gmel.     Conch.  Icon.,          .         .         .  158 
77-79.  Chiton  canariensis  Orb.     Moll.  Canar.,        .         .         .184 

PLATE  35. 

80.  Chiton  marmoreus  Rv.  (=squamosus  L.).      Conch.  Icon.,  155 

81.  Chiton  s«iuamosus  L.,  one-half  valve.     Pilsbry  del.,  .   !">"> 


342  i:\ri.\NATIONOFPLATE8. 

82.  Chiton  squaruosus  L.     Ross  del., 155 

83,84.  Chiton  insularis  Rochebr.  Nouv.  Arch.,  .  .  .  183 
85,  86.  Chiton  hamyi  Hochebr.  Nouv.  Arch.,  .  .  .183 
87,  88,  90.  Chiton  o'livaceus  Speng.  Pilsbry  del.,  .  .  180 
89,  91,92.  Chiton  olivaceus  Speng.  Ross  del.,  .  .  .180 
93.  Chiton  affinis  Issel.  Savigny, 181 

PLATE  36. 

91.  Chiton  jugosus  Gould.     U.  S.  Exped.,      .         .         .         .178 

92.  94,  95.  Chiton  jugosus  Gould.     Pilsbry  del.,     .         .         .  17K 

93.  Chiton  jugosus  Gould.     Ross  del., 178 

96,  97.  Chiton  jereus  Rve.     Conch.  Icon.,       .         .         .         .179 
98,  99.  Chiton  marquesanus  Pils.     Pilsbry  del.,      .         .         .  170 

100.  Chiton  marquesanus  Pils.     Ross  del.,        .  .  .  .170 

1.  Chiton  sinclairi  Gray.     Erebus  &  Terror,  .  .  .  174 

2,  3.  Chiton  sinclairi  Gray.     Pilsbry  del.,     .  .  .  .174 
4,6.  Chiton  canaliculatus  Q.     Pilsbry  del.,  .  .  .177 

5.  Chiton  insculptus  Ad.  (—canaliculatus  Q.).     P.  Z.  S.,      .  177 

PLATE  37. 

6.  Chiton  quoyi  Desh.  (color  var.).     Ross  del.,  .  .         .172 

7.  Chiton  quoyi  Desh.  (sculpture)  Pilsbry  del.,  .  .         .  172 

8.  Chiton  quoyi  Desh.     Conch.  Icon.,  .    *     .  .  .         .  172 

9.  10.  Chiton  caliginosus  Rve.     Conch.  Icon.,  .  Appendix. 

11.  Chiton  dissimilis  Rve.     Conch.  Icon.,        ....  184 

12,  13.  Chiton  muricatus  Ad.     P.  Z.  S.,          .         .         .         .175 
14,  15.  Chiton  pellisserpentis  Q.     Ross  del.,  .         .         .173 

16.  Chiton  pellisserpentis  Q.     Astrol.,  .         .         .        .173 

17.  Chiton  pellisserpentis  Q.  (1  sq.  mill,  of  the  girdle  indicated). 

Pilsbry  del 173 

18.  Chiton  pellisserpentis  Q.     Emertou  del.,  .  .173 

PLATE  38. 

19.  Chiton  subfuscus  Sowb.  typical.    Conch.  Icon.,         .    162,  163 

20.  Chiton  subfuscus  var.  mesoglyptus  Pils.     Conch.  111.,        .  164 

22.  Chiton  subfuscus  var.  mesoglyptus  Pils.     Ross  del.,          .  164 

21.  Chiton  subfuscus  var.  mesoglyptus,  valve  of  same  specimen 

as  fig.  22.     Pilsbry  del. 164 

23.  Chiton  bowenii  King.     Conch.  Illustr.,     .         .  .         .164 
•J4-26.  Ischnochiton  sulcatus  Q.  &  G.     Voy.  Astrol.,  .         .  138 
27,  28.  Chiton  tenuistriatu*  Sowb.     Conch.  111.,      .  .         .  188 
29,  30.  Chiton  cingillatus  Rve.     Conch.  Icon.,         .  Appendix. 
31,  32.  Chiton  luzonicus  Rve.     Conch.  Icon.,          .  Appendix. 
33,34.  Chiton  aquatilis  live.     Conch.  Icon.,  .  169 

PLATE  39. 
35.  Tonicia  disjunct:!  Fremb.     Conch.  Icon..  .         .         .  212 


\  N  \  TIMS  01    PI  LTBB. 


36—11.  Tonicia  disjunct*  I-'n-mh.     Kmcrton  <ld.,   . 

42—  '1.    <  'r:i-|irdi'diili>n  l:i<|  uc;it  u>  Sli  ul  (.      Kinrrtoii  del., 

52.  [iohnooniton  ragulatui  Sowb  var,    Condi.  Iron.,     .        .  no 

PLATE  40. 

1,2.  Tonieia  truncate  Sowb.    Condi.  Icon.,        .  .  .  LMI 

.3,4.  Tonioia  fortilirate  Sowb.    Condi.  Icon.,       .  .  .  _<>7 

5,6.  Tonirin  j»ii'ta  So\vh.     Conch.  Icon.,       .         .  .  .211 

7.  Tonicia  carpenteri  Angas.    P.  Z.  S.,        ....  iio.s 

8-11.  Tonicia  lamellosa  Q.  &  G.     Voy.  Astrol.,    .  .  ,209 

12.  Tonicia  /sdumi  I'flr.     Moll.  S.  Georg.,     .         .  .  ,204 

13-15.  Tonieia  tehuelchus  Orb.     Voy.  Ame>.  Me*rid.,  .  .  205 

16,  17.  Tonieia  suezensis  Rve.     Conch.  Icon.,         .  .  .  206 

PLATE  41. 

19.  Tonieia  chilensis  Fremb.     Pilsbry  del.,     .         .         .         .  l'.»7 

20.  Tonieia  chilensis  Fremb.     Conch.  Icon.,  .         .         .         .197 

21.  Tonicia  fastigiata  Sowb.     Pilsbry  del,      .         .         .         .199 

22.  Tonieia  elegans  Fremb.     Pilsbry  del.,      .         .         .         .196 
Betw.  22  and  24.  Touicia  elegans  Fremb.  (color-pattern  only). 

Pilsbry  del.,  ........         .  ]S6 

24.  Tonieia  elegans  Fremb.  (second  valve).     Pilsbry  del.,      .  196 

25.  Tonieia  lineolata  Fremb.     Conch.  Icon.,  .         .         .         .198 

26.  Tonieia  lineolata  Fremb.     Zool.  Journ.,    ....  198 

27.  Tonieia  lineolata  (var.  connecting  with  elegans).      Ross 

del.,       ..........  198 

28.  Tonieia  atrata  Sowb.     Conch.  111.,  .         .         .         .201 

29.  30.  Tonieia  atrata  Sowb.     Conch.,  Icon.,  .         .         .201 

PLATE  42. 

31.  Tonieia  elegans  Fremb.     Ross  del.,  .        .         .         .196 

32.  Tonieia  elegans  Fremb.  var.     Conch.  Icon.,      .         .         .196 

33.  34,  35.  Tonieia  elegans  Fremb.  (not  typical).      Emerton, 

del.,       .......         .         .         .196 

36-39.  Tonieia  fastigiata  Gray.     Conch.  Icon,        .         .         .199 

40.  Tonieia  chilcensis  (=fastigiata).     Conch.  Icon.,         .         .199 

PLATE  43. 

41.  Tonieia  swainsoni  Sowb.     Conch.  Icon.,   ....  201 

42.  Tonieia  swainsoni  Sowb.     Pilsbry  del.,     ....  201 
4.'>.  Tonieia  swainsoni  Sowb.     Ross  del.,          ....  201 
44,  45.  Tonieia  granifera  Sowb.     Conch.  Icon.,       .         .         .  200 
46,  47.  Tonieia  grayi  Sowb.     Conch.  Icon.,    ....  200 
48,  49.  Tonieia  (?)  martieli  Rochebr.     Moll.  Cap  Horn,         .  203 
50,  51.  Tonieia  horniana  Rochebr.     Moll.  Cap  Horn,     .         .  203 
52,  53.  Tonieia  lebruni  Rochebr.     Moll.  Cap.  Horn,      .         .  203 


344 


EXPLANATION  OF  PLATES. 


54,55.  Tonicia  sch  ram  mi  Shuttle  w.     Pilsbry  del.,          .         .  205 

56,  Tonicia  schrammi  Shuttlew.     Journ  de  Conch.,        .         .  205 

PLATE  44. 

57,  60.  Chaetopleura  watsoni  Sowb.     Conch.  Icon.,    See  appendix. 

58,  59.  Chsetopleura  watsoni  Sowb.     Conch.  111.,       See  appendix. 

61.  Chaetopleura  castanea  Q.     Voy.  Astrol.,  .   See  appendix. 

62.  Chaetopleura  fulva  Wood.     Ross,  del.,      .         .   See  appendix. 

63.  Chsetopleura  fulva  Wood.     Conch.  Icon.,          .   See  appendix. 

64.  Chaetopleura  fulva  Wood.     Pilsbry  del.,  .         .    See  appendix. 

65.  67.  Tonicia  rubridens  Pils.     Pilsbry  del.,          .         .         .202 

66.  Tonicia  rubridens  Pils.     Ross  del., 202 

68.  Craspedochiton  laqueatus  Sowb.     Conch.  Icon.,        .         .  285 

PLATE  45. 

69,  70.  Tonicia  crenulata  Sowb.     Conch.  Icon.,      .         .  195 
71,  72.  Tonicia  crenulata  Sowb.     Ross  del.,    .         .         .            195 

73.  Chiton  rubicundus  Costa.     Catal.,     ....  182 

74,  75.  Chiton  pulchellus  Phil.  (=rubicundus  Costa).    Enum.  182 
76,  77.  Acanthopleura  borbonica  Dh.     Pilsbry  del.,       .  230 
78,  79.  Acanthopleura  borbonica  Dh.     Moll.  Reun.,       .  230 
80,  81,  83,  84.  Acanthopleura  spinosa  Brug.  (valves  i,  ii,  viii) 

Emerton  del., 220 

82,  87.  Acanthopleura  spinosa  Brug.  (valve  iv).     Pilsbry  del.,  220 

85.  Acanthopleura  spinosa  Brug.     Conch.  Icon.,     .         .         .  220 

86.  Acanthopleura  spiuosa  Brug.  (girdle  spines).      Emerton 

del.,       ....  220 

PLATE  46. 

88.  Eudoxochiton  nobilis  Gray  (type).     Erebus  &  Terror,     .  193 

89,  90.  Eudoxochiton  nobilis  Gray  (valve  vii).     Pilsbry  del.,  193 
91.  Eudoxochiton  nobilis  Gray  (interior).     Emprton  del.,      .  193 
92-94.  Eudoxochiton  nobilis  Gray  (valve  viii).     Pilsbry  del.,  193 

95.  Eudoxochiton  nobilis  Gray.     Pilsbry  del.,         ;         .         .193 

96,  100.  Eudoxochiton  huttoni  Pils.  (valve  vii).     Pilsbry  del.,  194 

97.  Eudoxochiton  huttoni  Pils.     Ross  del.,     ....  194 

98,  99.  Eudoxochiton  huttoni  Pils.  (valve  viii).     Pilsbry  del.,  194 
1-5.  Chiton  miles  Cpr.     Emerton  del.,          .         .  .  188 

PLATE  47. 

6-9,  11-14.  Acanthopleura   echinatum    Barnes.      Emerton 

del., 218 

10.  Acanthopleura  echinatum  Barnes.  Zool.  Journ.,  .  .  218 
15-17.  Acanthopleura  echinatum  (young).  Emerton  del.,  .  218 
18-20.  Acanthopleura  brevi>pin<»>:i  ><i\vli.  Kmerton  del.,  .  231 
21.  Acanthopleura  brevispinosa  Sowb.  Ro&s  del.,  .  .  231 


EXPLANATION  OF  FLA1 

PLATE  48. 

22.  Acanthoplruni  spinier  Sowl).     Charlc.sworth's  Mag.  Nat. 

Hist.,     .        .  .        .  .        .  221 

23.  Aoanthopleara  ipiniger  Sowb.    Conch.  Illustr.,       .        .  L'LM 
•J  I   •_''',.  AcaiitIi(>|)l(Mira  spiniger  Sowb.  (Interior,  and  posterior 

valv,-).      1'ilsbry  del., .          .221 

27.  Acanthoploiira  spiniger  Sowb.     Conch.  Icon.,  .         .221 

28.  Acanthopleura  spiniger  var.  granata  Rv.     Pilsbry  del.,     224, 

[225 

29.  30.  Acanthopleura  spiniger   var.    granata    Rv.     Conch. 

Icon.,     .        .        .         .        .         .         .         .         .    224,  225 

31.  Acanthopleura  spiniger  var.  (Viti  Is.)     Ross  del.,    .         .  223 

32.  Acanthopleura  spiniger  var.  (Viti  Is.).     Pilsbry  del.,       .  223 

PLATE  49. 

33,34.  Acaiithopleura  spiniger  var.  cunninghami  Rve.  Conch. 

Icon 225 

35,  36.  Chiton   linter   (Chemn.)   Rve.      Conch.   Icon.,    (See 

appendix.) 
37,  38.  Chiton  piceus  Rv.  not  Linn.  (=A.  spiniger  var.  obesa 

Shuttl.) .         .226 

PLATE  50. 

39.  Acanthopleura  granulata  Gmel.  (St.  Thomas).      Ross  del.,  227 

40,  41.  Acanthopleura  granulata  Gmel.  (group  of  white  and 

of  dark  spines).     Pilsbry  del., 227 

42.  Acanthopleura    granulata   Gmel.    (occidentalis   Reeve). 

Conch.  Icon., 227 

43.  Acanthopleura  granulata  (Key  Vaccas,  Fla.).      Ross  del.,  227 
44-47.  Acanthopleura    granulata     Gmel.     (St.     Domingo). 

Pilsbry  del., 227 

48.  Acanthopleura  granulata  Gmel.  (St.  Thomas).      Ross  del.,  227 

49.  Acanthopleura  granulata  Gmel.     Emerton  del.,         .         .  227 

PLATE  51. 

1.  Schizochiton  incisus  Sowb.  235 

2.  Schizochiton  incisus  Sowb.  (half  of  head  valve).     O.  J. 

M.  S., .  235 

3.  Schizochiton  incisus  Sowb.  (eye,  x  200).     Q,  J.  M.  S.,      .  235 
4-5.  Schizochiton  incisus  Sowb.  (valves  i  and  ii).     Emerton 

del., 235 

6-8.  Schizochiton  incisus  Sowb.  (valve  viii,  ventral,  profile 

and  posterior  views).  Emerton  del.,  ....  235 
9-12.  Lorica  angasi  Ad.  &  Ang.  Emerton  del.,  .  .  .  238 


346  I :  X  I  -LANATION  OF  PLATES. 

PLATE  52. 

14.  Lorica  cimolea  Rv.  (=volvox  Rve.).     Conch.  Icon.,        .  237 

15.  Lorica  volvox  Rve.    Ross  del., 237 

16.  Lorica  volvox  Rv.  (1  sq.  mill,  of  girdle).     Pilsbry  del.,    .  237 

17.  18.  Lorica  volvox  Rv.  (posterior  valve).     Pilsbry  del.,     .  237 

19,  Lorica  volvox  Rv.  (anterior  valve).     Pilsbry  del.,    .         .  237 

20,  21.  Lorica  volvox  Rv.  (intermediate  valve).     Pilsbry  del.,  237 
22,  23.  Enoplochiton  niger  Barnes  (posterior  valve).     Emer- 

ton  del., 252 

24, 25.  Enoplochiton    niger   Barnes    (intermediate    valve). 

Pilsbry  del.,  .  .  .          .  .252 

26.  Enoplochiton  niger  Barnes.     Ross  del.,    ....  252 

27.  Enoplochiton  niger  (surface).     Q.  J.  M.  6.,      .         .         .  252 

28.  Enoplochiton  niger  (surface).     Q.  J.  M.  S.,     .  .  252 

29.  Enoplochiton  niger  (girdle  of  a  young  specimen).     Emer- 

ton  del., 252 

PLATE  53. 

30.  Liolophura  iucanaGld.(=L.  gaimardi  Blv.).    U.  S.  Expl. 

Exped., 240 

31.  Liolophura  gaimardi  Blv.  (girdle  spines).     Pilsbry  del.,  .  240 

32.  Liolophura  gaimardi  Blv.     Ross  del.,       ....  240 
33-35.  Liolophura  gaimardi  Blv.     Pilsbry  del.,      .         .         .240 
36-40.  Liolophura  georgiana  Q.  &  G.     Voy.  Astrol.,     .         .  241 

41.  Liolophura  japonica  Lisch.  (Girdle  spines).     Pilsbry  del.,  242 

42.  Liolophura  japonica  Lisch.     Ross  del.,    ....  242 

43.  44.  Liolophura  japonica  Lisch.    Jap.  Meeres-Conch.,       .242 

45.  Liolophura  japonica  var.  tessellata  Pils.     Ross  del., 

46.  Liolophura  japonica  var.  tessellata  Pils.     Pilsbry  del.,     .  243 

PLATE  54. 

21,  22.  Nuttallina  scabra  Rv.     Pilsbry  del.,  .         .  .  .280 
•2 :;,  24.  Nuttallina  californica  Nutt.     Pilsbry  del.,  .  .  279 
25-27.  Nuttallina  alternataSowb.     Conch.  111.,     .  .  .281 
28-30.  Nuttallina  cinerea  Poli.     Emerton  del.,      .  .  .  283 

31.  Nuttallina  cinerea  Poli  (edge  of  girdle  x  100).     Pilsbry 

del., 283 

32.  Nuttallina  cinerea  Poli.     Test.  Utr.  Sic.,  .         .         .         .283 

33.  Nuttallina  cinerea  Poli  (girdle  x  50  ca.)     Pilsbry  del.,    .  283 

34.  35.  Plaxiphora  ovata  Hutt.     Pilsbry  del.,        .    '     .        .332 
36-39.  Plaxiphora  ovata  Hutt.  (profile,  posterior,  dorsal  and 

ventral  views  of  posterior  valve).  Pilsbry  del.,  .  .  332 
40.  Plaxiphora  ovata  Hutt.  (sculpture  of  intermediate  valves). 

I'ilsbrydel., 332 

41-45.  O.  caliginosus  Cpr.  (=Liolophura  japonica  Lisch.) 

Emerton  del.,  .  244 

46.  Onithochiton  amicorum  Bd.  Voy.  Curacoa,  .  .  .249 


i  \I-I.\N  M  i«. N  MI-   PLJ 

* 

l'l.\  I  ! 

1.  Onjthocbiton  lyellii  8owb.    ('..ndi.  IIIu*tr 247 

2.  Onitbocbiton  lyelli)  Sowb.    Condi.  Icon.,        .        .        .  LM? 
3-7.  Onitbocbiton  lyellii  8owb,     Bmerton  del.,    .        .        .247 

8,9.  Onithodiiton  iiidi  IIv.  (  lydlii  S.»w!).).  Conch.  Icon.,  248 
10,  11.  Onithudiitoii  srmisnrlptus  Pils.  Koss  del.,  .  ,247 
12,  13.  Onithudiitoii  <|iirrdmis(;l<l.  I'.  S.  Kxped., 
14,  1.").  ( )nitlmdiit<m  undulatus  Q.  &  G.  Roes  del,  .  .245 
L6.  Onitbocbhon  undulatas  Q.  ft  G.  Voy.  Astrol.,  .  .240 
17, 18.  Plaxiphora  wahlbergi  Kr.  sndaf.  Moll.,  .  .  .322 

19.  Onithoehiton  ragulotns  Anff.    P.  Z.  S.,    .        .        .        .249 

20.  Onithoehiton  maillardi  Desh.     Moll.  Reun.,     .         .         .  250 
21-23.  Onithoehiton  literatus  Kr.     Sudafrik.  Moll.,       .         .  251 

PLATE  56. 

1,  4,  6.  Pallochiton  lanuginosus  Cpr.     Ross  del.,  .         .  257 

2,  3.  Pallochiton  lanuginosus  Cpr.     Pilsbry  del.,  .         .  257 
5,  7-11.  Pallochiton  lunuginosus  Cpr.     Emerton  del.,  .         .  2~>7 

12-16.  Nuttallina  californica  Nutt.  Emerton  del.,  .  .  279 
17,  18.  Nuttallina  californica  Nutt.  Ross  del.,  .  .  .279 
19,  20.  Nuttallina  scabra  Rve.  Ross  del.,  .  .  .  .280 

PLATE  57. 

21.  Dinoplax  gigas  Gmel.     Conch.  Icon.,        ....  255 

22.  27-31.  Dinoplax  gigas  Gmel.     Emerton  del.,   .         .         .  255 
23-26.  Dinoplax  gigas  Gmel.  (young).     Siidafrik.  Moll.,       .  255 

32.  Dinoplax  gigas  Gmel.  (young).     Ross  del.,       .         .         .  255 

33.  35.  Tonicia  confossa  Gld.     Pilsbry  del.,   .         .         .         .210 

34.  Tonicia  confossa  Gld.    U.  S.  Expl.  Exped.,      .        .         .210 

PLATE  58. 

1,  2.  Callistochiton  crassicostatus  Pils.     Emerton  del., .         .  264 
3-6.  Callistochiton  crassicostatus  Pils.     Pilsbry  del.,    .         .  264 
Fig.  below  1,  and  7,  8.  Callistochiton  palmulatus  Cpr.    Emerton 

del.,       .         .         .         .         .         .        .         .         .         .262 

9-11.  Callistochiton  palmulatus  var.  mirabilis  Pils.     Pilsbry 

del., 263 

12.  Callistochiton  palmulatus  (typical).  Pilsbry  del.,  .  .  262 
13-16.  Callistochiton  palmulatus  (typical).  Emerton  del.,  .  262 
17.  Callistochiton  decoratus  Cpr.  Ross  del.,  .  .  .  269 

18-20.  Callistochiton  decoratus  Cpr.  Pilsbry  del.,  .  .  269 
21,  22.  Plaxiphora  ccelata  Rve.  Conch.  Icon.,  .  .  .328 

PLATE  59 

21-26.  Callistochiton    pulchrior    Cpr.   (=pulchellus   Gray). 

Foord  del.,     .  .  272 


348  EXPLANATION  OF  PLATES. 

27,  28.  Callistochiton  elenensis  Sowb.    Conch.  111.,  .  .  267 

29,  34.  Callistochiton  antiquus  Rv.     Pilsbry  del,  .  .  .  274 

30-32.  Callistochiton  antiquus  Rv.     Emerton  del.,  .  .  274 

35.  Callistochiton  antiquus  Rv.     Conch.  Icon.,       .  .  .  274 

36.  Callistochiton  coppingeri  Sm.     '  A'lert '  Zool.,  .  .  .  275 
•".7-42.  Callistochiton  infortunatus  Pils.     Foord,  del.,  .  .  266 
43,  44.  Callistochiton  bicostatus  Orb.   (=pulchellus  Gray). 

V,,y.  Am.  Mrr., 272 

45.  Callistochiton  adenensis  Smith.     P.  Z.  S.,          .         .         .278 

PLATE  60. 

1.  Callistochiton  pulchellus  Gray.    Spicil.  Zool.,  .         .         .  271 

2.  Callistochiton  pulchellus  Gray.     Conch.  Icon.,          .         .  271 
3-6.  Callistochiton  pulchellus  Gray.     Pilsbry  del.,       .         .271 

7-10.  Callistochiton  gabbi  Pils.     Pilsbry  del.,         .  .         ,270 

11-15.  Callistochiton  (?)  heterodon  Pils.,        .         .  ...  276 

16.  Callistochiton   (?)   heterodon  var.   savignyi  Pils.  Savig. 

^Egypt,  .  277 

PLATE  61. 

17-22.  Callistoplax  retusus  Sowb.     Emerton  del.,  .         .  288 

23,  24.  Callistoplax  retusus  Sowb.     Emerton  del.,  .         .         .  288 

25.  Callistoplax  retusus  Sowb.     Conch.  Illustr.,      .         .         .  288 

26.  Callistoplax  retusus  Sowb.    Conch.  Icon.,          .         .         .  288 
27-32.  Angasia  tetrica  Cpr.     Emerton  del.,   ....  287 

33.  Ceratozona  rugosa  Sowb.    Conch.  111.,      ....  290 

34.  Ceratozona  rugosa  Sowb.  (Santa  Cruz).     Pilsbry  del.,       .  290 

35.  Ceratozona  rugosa  Sowb.     Pilsbry  del.,    .         .         .         .  290 

36.  Ceratozona  rugosa  Sowb.  (Jupiter  Inlet).     Pilsbry  del,    .  290 

37.  Ceratozona  guildingii    Rv.   (r=rugosa    Sowb.)      Conch. 

Icon., 290 

38.  39.  Ceratozoua  setosa  Sowb.     Emerton  del.,     .         .        .292 
40.  Ceratozona  setosa  Sowb.    Conch.  111.,       .         ,         ...  292 
41-45.  Ceratozoua  rugosa  Sowb.     Emerton  del.,    .         .        .  290 

PLATE  62. 

84,  85.  Placiphorella  stimpsoni  Gld.  (tail  valve).   Pilsbry  del.  307 

86.  I'hiriphon-lhistimpsoiii  Gld. (girdle- hair).    Carpenter  del.  307 

87.  Placiphorella  stimpsoni  Gld.     Ross  del.,           .         .  307 
88-92.  Mopalia  middendorffii  Schr.    Amurl.  Moll.,       .  301 

93.  Mopalia  mii.-c<>-a  var.  porifera  Pils.     Pilsbry  del.,    .  297 

94.  Mopalia  muscosa  var.  porifera  Pils.     Ross  del.,        .  297 

95.  Mopalia  sinuata  Cpr.  (girdle).     Emerton  del.,          .  303 
96  (upper  fig.).  Mopalia  sinuata  Cpr.     Ross  del.,            .  303 
96    (lower   three  figs.'.   M"|»;ilia    sinuata    Cpr.    (tail    valve) 

Emerton  del 303 


i AIM  \v  \  i  [OH  OF  I'LVTES.  349 

97.   M«»pali:i  >imint:i  <  'pr.  <  intrnin-di:it»-  v;,lvr  ).        I'iUbry  d«-l  . 
J».S.   Mopalia  imporcata  ('pr.  (intermediate  valve).        i'ilsbrv 

del ... 

99.   Mopalia  muscosa  var.  liindsii  I'.d.      I'iUhry  del., 
100.  Mopalia  muscosa  var.  liindsii  P,d.     Ro.ss  del.,    .         .         .  li'.MI 

PLATE  63. 

46.  Mopalia  musi-osa  ( ild.  (typical).     U.  S.  Expl.  Exped.,      . 

47,48.  Mopalia  museosa  Gld.     Ross  del.,       ....  295 

49-50.  Mopalia  muscosa  Old.     Emerton  del.,         .         .         .  295 

57.  Mopalia  muscosa  var.  hindsii  Bd.     Conch.  Icon.,      .         .  296 

58,  59.  Mopalia  lignosa  Gld.     Ross  del.,         ....  299 

60.  Mopalia  lignosa  smooth  form.     Ross  del.,         .         .  .  300 

61.  Mopalia  lignosa  smooth  form.     Pilsbry  del.,     .         .  .  300 

62.  Mopalia  lignosa  (vespertina  Gld.).     U.  S.  Ex.  Exped.,  .  300 

63.  Mopalia  insignis  Newc.  (=lignosa  Gld.)  300 

PLATE  64. 

64-68.  Mopalia   ciliata  Sowb.  (Monterey     Bay).     Ross  & 

Pilsbry  del.,  .         .         .         .         .  .         .         .303 

69,70,71.  Mopalia  ciliata  var.  wosnessenkiiMidd.   Mai.  Ross.  305 

72.  Mopalia  ciliata  var.  wosnessenskii  Midd.     Pilsbry  del.,     .  305 

73.  Mopalia  ciliata  var.  wosnessenskii  Midd.     Ross  del.,          .  305 
,  74.  Mopalia  muscosa  Gld.     Emerton  del.,      ....  295 

75.  Mopalia  acuta  Cpr.     Ross  del., 297 

76-79.  Mopalia  acuta  Cpr.  (tail  valves).  Pilsbry  del.,  .  .  297 
80,  81.  Mopalia  plumosa  Cpr.  (=racuta  Cpr.).  Foord  del.,  .  298 
82,  83.  Mopalia  lignosa  form  elevata.  Ross  del.,  .  .  .  300 

PLATE  65. 

73-75.  Plaxiphora  atlantica  V.  (tail  valve).  Pilsbry  del.,  .  313 
7H.  Plaxiphora  setiger  King.  Conch.  Icon.,  .  .  .316 

77,  78,  79.  Plaxiphora  setiger  King.  Emerton  &  Ross  del.,  316 
80-82.  Plaxiphora  egregia  Ad.  P.  Z.  S.,  ...  331 

PLATE  66. 

6,  7.  Placiphorella  velata  Cpr.     Emerton  del.,      .         .         .  306 
8-10.  Placiphorella  velata  Cpr.  (posterior  valve).      Pilsbry 

del.,       ....  .....  306 

11.  Placiphorella  velata  Cpr.  (intermediate  valve).      Pilsbry 

del., 306 

12.  Placiphorella  velata  (Insertion-plate,  seen  from  end   of 

valve).     Pilsbry  del., 306 

13.  Placiphorella  velata  (girdle-hair).     Pilsbry  del.,      .         .  306 

14.  Placiphorella  borealis  Pils.  (intermed.  valve).   Pilsbry  del.,  309 


.0>.")n  i:\ri.\NATION  OF  PLATES. 

1 .",  Placiphorella  borealis  Pils.  (Insertion-plate  seen  from  end 

of  valve).  Pilsbry  del, 309 

16,  17.  Placiphorella  borealis  Pils.  (posterior  valve).  Pilsbry 

del, 309 

18-24.  Placophoropsis  atlantica  V.    Tr.  Conn.  Acad.,   .         .  313 

25.  Placiphorella  petasus  Rv.     Conch.  Icon.,          .         .         .311 

26,  27.  Placiphorella  blainvillii  Sowb.     Conch.  Icon.,     .         .  310 
28-32.  Placiphorella  blainvillii  Sowb.     Emerton  del.,    .         .310 

PLATE  67. 

33-36.  Plaxiphora  carpenteri  Had.    Chall.  Rep.,  .         .  325 

S8.  Cha-topleura  hahni  Rochebr.  (=Plaxiphora  fremblyi) 

B.     Cap  Horn, 
39,  40.  Chietopleura  frigida  Rochebr.  (=Plaxiphora  setiger, 

young).     Miss.   Cap  Horn,  317 

41,  42.  Chietopleura  savatieri  Rochebr.  (=  Plaxiphora  setiger) 

Miss.  Cap  Horn, 317 

43-46.  Plaxiphora  simplex  Cpr.     Chall.  Rep., 

PLATE  68. 

.">l-54.  Plaxiphora  biramosa  Q.  &  G.,    Voy.  AstroL,  .  .  319 

55-61 .  Plaxiphora  superba  Cpr.  (=biramosa  Q.).  Emerton  del.  319 

62,  64.  Plaxiphora  petholata  Sowb.     Pilsbry  del.,  .  .  323 

63,  66.  Plaxiphora  petholata  Sowb.     Emerton  del.,  .  .  323 
65.  Plaxiphora  petholata  Sowb.     Ross,  del.,           .  .  .  323 
67.  Plaxiphora  petholata  Sowb.     Conch.  Illustr.,   .  .  .  323 
68-72.  Plaxiphora  glauca  Q.  &  G.     Voy.  AstroL,  .  .  326 


NOTE.— The  Parts  of  Vol.  XIV  of  the  MANUAL  were  issued  to 
subscribers  upon  the  following  dates : 

Part  53,  including  pp.  1-  64,  plates  1-15,  July  25,  1892, 
Part  54,  "  "  65-128,  "  16-30,  Nov.  25,  1892. 
Part  55,  "  "129-208,  "  31-40,  Feb.  25,  1893. 
Part  56,  "  "  209-350,  "  41-68,  June,  1893. 

The  Title  page,  Preface  and  Introduction  to  Polyplacophora, 
accompany  Part  tffl.  J"^  & 

END  OF  VOL.  XIV. 


POLYPLACOPHORA. 


PLATE     1 


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90  <*""* 


POLYPLACOPHORA. 


PLATE    2 


POLYPLACOPHORA. 


PLATE     3 


POLYPLACOPHORA. 


PLATE      4 


POLYPLACOPHORA. 


PLATE     5 


POLYPLACOPHORA. 


PLATE    6 


POLYPLACOPHORA. 


PLATE     7 


POLYPLACOPHORA. 


PLATE     8 


84 


POLYPLACOPHORA. 


PLATE      9 


91 


POLYPLACOPHORA. 


PLATE     1O 


POLYPLACOPHORA. 


PLATE      11 


POLYPLACOPHORA. 


PLATE     12 


POLYPLACOPHORA. 


PLATE    13 


POLYPLACOPHORA. 


PLATE     14 


86 


POLYPLACOPHORA. 


PLATE     15 


POLYPLACOPHORA. 


PLATE    16 


POLYPLACOPHORA. 


PLATE     17 


19 


POLYPLACOPHORA. 


PLATE     18 


POLYPJLACOPHORA. 


PLATE    19 


1 


63 


POLYPLACOPHORA. 


PLATE    20 


.;] 


24- 


POLYPLACOPHORA. 


PLATE     21 


POLYPLACOPHORA. 


PLATE   22 


74- 


POLYPLACOPHORA. 


PLATE    23 


PLATE    24 


POLYPLACOPHORA. 


I 


POLYPLACOPHORA. 


PLATE    25 


POLYPLACOPHORA. 


PLATE  26 


I 


34 


POLYPLACOPHORA. 


PL. ATE    27 


POLYPLACOPHORA. 


PLATE     28 


POLYPLACOPHORA. 


PLATK 


Ib 


POLYPLACOPHORA. 

4^1 


PLATE     3O 


POLYPL.ACOPHORA. 


PLATE   3! 


POLYPLACOPHORA. 


PLATE     32 


56 


POLYPLACOPHORA. 


PLATE    33 


63 


67 


POLYPLACOPHORA. 


PLATE    34 


74 


POLYPLACOPHORA. 


PLATE    35 


POLYPLACOPHORA. 


PLATE   36 


91 


POLYPLACOPHORA. 


PLATE  37 


POLYPLACOPHORA, 


PLATE    38 


33 


POLYPLACOPHORA. 


PLATE     39 


POL.YPLACOPHORA. 


PLATE  40 


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14 


POLYPLACOPHORA. 


PLATE    41 


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POLYPLACOPHORA. 


PLATE     42 


J3J 


5R» 

34 


37 


POLYPLACOPHORA. 


PLATE     43 


POLYPLACOPHORA. 


PLATE    44 


63 


POLYPLACOPHORA. 


PLATE     45 


|P 


POLYPLACOPHORA. 


PLATE      46 


POLYPLACOPHORA. 


PI-ATE     47 


POLYPLACOPHORA. 


PLATE     48 


POLYPLACOPHORA. 


PLATE     49 


37 


POLYPLACOPHORA. 


PLATE     5O 


48 


POLYPLACOPHORA. 


PLATE      51 


POLYPLACOPHORA. 


'-:'i.:i:j. 

28 


POLYPLACOPHORA. 


PLATE     53 


1mm 


POLYPLACOPHORA. 

I  - 


PLATE    54 


.! 


Imin 


POLYPLACOPHORA. 


PLATE     55 


POLYPLACOPHORA. 


PLATE     56 


POLYPLACOPHORA. 


POLYPLACOPHORA. 


PLATE    58 


u  ^ 


POLYPLACOPHORA. 


1  mm 


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31 


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PLATE    50 


26 


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POLYPLACOPHORA 


PLATE    6O 


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1mm. 


POLYPLACOPHORA. 


PLATE     61 


PLATE     62 


POLYPLACOPHORA. 


F 


96  N 


& 


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POLYPLACOPHORA. 


PLATE    63 


POLYPLACOPHORA. 


PLATE    64 


POLYPLACOPHORA. 


PLATE     65 


78 


POLYPLACOPHORA. 


PLATE    66 


?.(T 


POLYPLACOPHORA. 


PLATE    67 


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45 


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