﻿I'ELECYPODA 
  

  

  71 
  

  

  Pecten 
  (Plagioctenium) 
  circularis 
  aequisulcatus 
  Carpenter 
  

  

  (PI. 
  3, 
  figs. 
  1-3) 
  

  

  Pecten 
  ventricosus 
  var. 
  aequisulcatus 
  Carpenter, 
  1864b, 
  p. 
  536, 
  540, 
  592, 
  599; 
  Reprint, 
  1872, 
  

  

  p. 
  22. 
  26, 
  78, 
  85; 
  Cooper, 
  1867, 
  Geog. 
  Cat. 
  Moll., 
  Geol. 
  Sur. 
  California, 
  p. 
  12; 
  Dall, 
  

  

  Wagner 
  Free 
  Inst. 
  Sci., 
  Philadelphia, 
  Trans., 
  vol. 
  Ill, 
  pt. 
  IV, 
  p. 
  711 
  

  

  Pecten 
  aequisulcatus, 
  ? 
  n.s. 
  Carpenter, 
  1864b, 
  p. 
  645, 
  669, 
  684; 
  Reprint, 
  1872, 
  p. 
  131, 
  155, 
  

  

  170 
  

   Pecten 
  (? 
  var.) 
  aequisulcatus 
  Carpenter, 
  1865, 
  Ann. 
  Mag. 
  Nat. 
  Hist., 
  ser. 
  3, 
  vol. 
  XV, 
  p. 
  

  

  179, 
  Reprint, 
  1872, 
  p. 
  280 
  

   Pecten 
  aequisulcatus 
  Carpenter, 
  Keep, 
  1887, 
  West 
  Coast 
  Shells, 
  p. 
  166, 
  fig. 
  139; 
  Kxister 
  and 
  

   Kobelt, 
  1888, 
  Conch. 
  Cab., 
  vol. 
  17, 
  pt. 
  2, 
  Spondylus 
  and 
  Pecten, 
  no. 
  294, 
  p. 
  269, 
  tab. 
  71, 
  

   figs. 
  1. 
  2; 
  Williamson, 
  1902, 
  So. 
  California 
  Acad. 
  Sci., 
  Bull., 
  vol. 
  1, 
  no. 
  5, 
  p. 
  51-61, 
  fig. 
  

   IV-VI 
  detailed 
  description 
  of 
  animal 
  and 
  shell 
  

   Pecten 
  {Plagioctenium) 
  ventricosus 
  Arnold, 
  1903, 
  p. 
  114, 
  pi. 
  XI, 
  figs. 
  3, 
  3a, 
  6, 
  6a 
  

   Pecten 
  {Plagioctenium) 
  nezcsomi 
  .Arnold, 
  1903, 
  p. 
  113, 
  pi. 
  XI, 
  figs. 
  1, 
  la 
  

   Pecten 
  circularis 
  var. 
  aequisulcatus 
  Carpenter, 
  Keep, 
  1911, 
  West 
  Coast 
  Shells, 
  p. 
  39, 
  fig. 
  19 
  

   Pecten 
  {Plagiocentenium) 
  circularis 
  Sowerby 
  var. 
  aequisulcatus 
  Carpenter, 
  Arnold, 
  1906, 
  

   U. 
  S. 
  Geol. 
  Sur., 
  Prof. 
  Paper, 
  no. 
  47, 
  p. 
  132, 
  pi. 
  L, 
  figs. 
  1, 
  la 
  text 
  figs. 
  1, 
  2 
  synonymy; 
  

   Dall, 
  1914, 
  Nautilus, 
  vol. 
  27, 
  no. 
  11, 
  p. 
  122; 
  Oldroyd, 
  1924b, 
  p. 
  58, 
  pi. 
  42, 
  figs. 
  1, 
  2 
  Ar- 
  

   nold's 
  figs, 
  section; 
  Burch, 
  1944, 
  no. 
  35, 
  p. 
  11, 
  fig.; 
  Burch, 
  1945, 
  no. 
  45, 
  p. 
  6 
  

   Not 
  ? 
  Pecten 
  {Aequipecten) 
  aequisulcatus 
  Carpenter, 
  Dautzenberg 
  and 
  Bavay, 
  1912, 
  

  

  Siboga-Expeditie, 
  Les 
  Lamellibranches, 
  Llllb, 
  p. 
  19 
  

   Pecten 
  {Chlamys) 
  circularis 
  aequisulcatus 
  Carpenter, 
  Dall, 
  1921, 
  p. 
  19 
  section 
  Plagiocenten- 
  

   ium 
  

   Pecten 
  {Aequipecten) 
  gibbus 
  Linnaeus 
  var. 
  circularis 
  Grant 
  and 
  Gale, 
  1931, 
  p. 
  218 
  in 
  part 
  

   Pecten 
  {Aequipecten) 
  circularis 
  aequisulcatus 
  Baely, 
  1935, 
  West 
  Coast 
  Shells 
  (Keep), 
  p. 
  52, 
  

  

  fig. 
  23; 
  Hertlein, 
  1935, 
  California 
  Acad. 
  Sci., 
  Proc, 
  vol. 
  XXI, 
  no. 
  25, 
  p. 
  313 
  

   Plagiotenium 
  circularis 
  aequisulcatum 
  (Carpenter), 
  Finch, 
  1953, 
  California 
  Fish 
  Game 
  

   Marine 
  Fish., 
  Fish 
  Bull., 
  no. 
  90, 
  p. 
  42, 
  fig. 
  8 
  

  

  For 
  other 
  references, 
  see 
  Arnold, 
  1906; 
  Grant 
  and 
  Gale, 
  1931, 
  in 
  part; 
  Keen, 
  1937, 
  p. 
  19 
  

   under 
  Chlamys; 
  Hertlein 
  and 
  Strong, 
  1946, 
  p. 
  58 
  

  

  The 
  types 
  of 
  this 
  species 
  consist 
  of 
  one 
  valve, 
  left 
  marked 
  "type," 
  and 
  one 
  double 
  speci- 
  

   men, 
  in 
  the 
  U. 
  S. 
  National 
  Museum, 
  no. 
  15645, 
  with 
  the 
  label 
  "San 
  Diego." 
  In 
  regard 
  to 
  

   the 
  statement 
  of 
  Mrs. 
  Oldroyd 
  concerning 
  the 
  Boyce 
  Collection, 
  see 
  the 
  introduction 
  to 
  this 
  

   paper. 
  The 
  note 
  as 
  to 
  the 
  whereabouts 
  of 
  the 
  types 
  in 
  the 
  British 
  Museum 
  in 
  Grant 
  and 
  

   Gale 
  was 
  a 
  supposition. 
  Arnold 
  gave 
  a 
  fine 
  photograph 
  of 
  a 
  typical 
  specimen 
  in 
  the 
  U. 
  S. 
  

   Nat. 
  Museum, 
  no. 
  172703, 
  but 
  that 
  specimen 
  is 
  not 
  the 
  type. 
  Oldroyd 
  (1924b) 
  copied 
  Car- 
  

   penter's 
  original 
  description 
  (1865h). 
  In 
  addition 
  to 
  that 
  description 
  Carpenter 
  stated: 
  

   "Hab. 
  Sta. 
  Barbara 
  {Jewett) 
  ; 
  S. 
  Diego 
  {Ca-ssidy, 
  Nezvberry, 
  Cooper)." 
  

   He 
  identified 
  the 
  species 
  amongst 
  the 
  collection 
  of 
  Major 
  Rich, 
  from 
  "Near 
  S. 
  Pedro." 
  

   [Carpenter, 
  1864b, 
  p. 
  540] 
  

  

  Dimensions. 
  — 
  Length, 
  84 
  mm.; 
  height, 
  80 
  mm.; 
  thickness 
  (1 
  valve), 
  14 
  mm. 
  left 
  valve, 
  

   "type"; 
  length, 
  69 
  mm.; 
  height, 
  64 
  mm.; 
  thickness 
  (double), 
  35 
  mm. 
  

   Syntypes. 
  — 
  U. 
  S. 
  National 
  Museum, 
  no. 
  15645 
  

  

  Distribution. 
  — 
  Recent. 
  San 
  Diego, 
  California 
  (type) 
  ; 
  Monterey 
  Bay, 
  California, 
  to 
  Cape 
  

   San 
  Lucas, 
  Lower 
  California 
  (Finch, 
  1953). 
  For 
  Pliocene 
  and 
  Pleistocene, 
  see 
  Table 
  2 
  for 
  

   stratigraphic 
  distribution. 
  

  

  Subgenus 
  Leptopecten 
  Verrill, 
  1897 
  

   Leptopecten 
  A'errill, 
  1897, 
  Connecticut 
  Acad. 
  Sci., 
  Trans., 
  vol. 
  X, 
  pt. 
  1, 
  p. 
  69 
  

   Type 
  species 
  by 
  original 
  designation, 
  Chlamys 
  monotimeris 
  (Conrad), 
  1837, 
  Acad. 
  Nat. 
  Sci. 
  

  

  Philadelphia, 
  Jour. 
  vol. 
  7, 
  p. 
  238, 
  pl. 
  18, 
  fig. 
  10. 
  Recent. 
  Monterey, 
  California, 
  to 
  Gulf 
  of 
  

  

  California. 
  Oldroyd, 
  1924b, 
  pl. 
  40, 
  figs. 
  1, 
  2 
  

  

  Pecten 
  (Leptopecten) 
  paucicostatus 
  Carpenter 
  

  

  Pecten 
  paucicostatus 
  Carpenter, 
  1864b, 
  p. 
  536, 
  614, 
  645 
  ; 
  Reprint, 
  1872, 
  p. 
  22, 
  100. 
  131 
  ; 
  1865, 
  

   Ann. 
  Mag. 
  Nat. 
  Hist, 
  ser. 
  3, 
  vol. 
  XV, 
  p. 
  179; 
  Reprint, 
  1872. 
  p. 
  281 
  ; 
  Kuster 
  and 
  Kobelt, 
  

   1888, 
  Alartini-Chemnitz, 
  Conchyl. 
  Cab., 
  vol. 
  17, 
  pt. 
  2, 
  p. 
  281. 
  Not 
  P. 
  prototranquebaricus 
  

   paucicostatus 
  Vredenburg, 
  1928 
  = 
  P. 
  p. 
  noetlingi 
  Hertlein, 
  1936, 
  Nautilus, 
  vol. 
  50, 
  p. 
  54 
  

  

  