﻿Marsipobranchs 
  of 
  the 
  Order 
  Ilyperoartii. 
  199 
  

  

  8. 
  720 
  mm. 
  Coruna. 
  Mons. 
  V. 
  L. 
  Seoane. 
  

  

  9. 
  800 
  mm. 
  Lisbon. 
  Rev. 
  R. 
  T. 
  Lowe. 
  

  

  10. 
  170 
  mm. 
  Mediterranean. 
  

  

  11. 
  210 
  mm. 
  W. 
  Africa. 
  J. 
  C. 
  Salmon, 
  Esq. 
  

  

  12. 
  180 
  mm. 
  Nova 
  Scotia. 
  M. 
  Jones, 
  Esq. 
  

   13, 
  14. 
  620-640 
  mm. 
  New 
  York. 
  

  

  15. 
  530 
  mm. 
  Merrimack 
  R. 
  

  

  16. 
  270 
  mm. 
  Muscatine, 
  Iowa. 
  Field 
  Mus. 
  

  

  17. 
  170 
  mm. 
  Val-de-Grace, 
  U.S.A. 
  Dr. 
  F. 
  Day. 
  

  

  Specimen 
  no. 
  11 
  has 
  the 
  supraoral 
  cusps 
  small 
  and 
  close 
  

   together 
  and 
  the 
  intraoral 
  cusps 
  weak, 
  as 
  described 
  for 
  

   Bathymyzon 
  bairdii. 
  

  

  4. 
  ICIITHYOMYZON. 
  

   Ichthyomyzon, 
  Girard, 
  Pac. 
  R. 
  R. 
  Surv. 
  x. 
  p. 
  381 
  (1858). 
  

  

  Disc 
  covered 
  with 
  radially 
  arranged 
  teeth. 
  A 
  single 
  

   narrow 
  bicuspid 
  or 
  tricuspid 
  supraoral 
  lamina 
  ; 
  intraoral 
  

   lamina 
  cuspidate. 
  Anterior 
  lingual 
  lamina 
  with 
  a 
  single 
  

   transverse 
  denticulated 
  ridge. 
  Dorsal 
  fins 
  united. 
  

  

  Eastern 
  North 
  America. 
  

  

  1. 
  Ichthyomyzon 
  bdellium. 
  

  

  Petromyzon 
  aryenteus 
  (non 
  Bloch), 
  Kirtland, 
  Bost. 
  Journ. 
  N. 
  H. 
  iii. 
  

  

  1840, 
  p. 
  342, 
  pi. 
  iv. 
  fig. 
  3. 
  

   Petromyzon 
  bdellium, 
  Jord. 
  Cat. 
  Fish. 
  N. 
  Am. 
  p. 
  4 
  (1885). 
  

   Ichthyomyzon 
  concolor, 
  Jord. 
  & 
  Everm. 
  Bull. 
  U.S. 
  Nat. 
  Mus. 
  xlvii. 
  

  

  1896, 
  p. 
  11 
  *. 
  

  

  Supraoral 
  lamina 
  bicuspid 
  ; 
  all 
  the 
  labial 
  teeth 
  unicuspid 
  ; 
  

   intraoral 
  lamina 
  with 
  7 
  cusps. 
  

  

  Great 
  Lakes 
  and 
  Upper 
  Mississippi. 
  

  

  1. 
  240 
  mm. 
  Louisville, 
  Kentucky. 
  Smithsonian 
  Inst. 
  

  

  2. 
  Ichthyomyzon 
  castaneus. 
  

  

  Ichthyomyzon 
  castaneus, 
  Girard, 
  Pac. 
  R. 
  R. 
  Surv. 
  x. 
  p. 
  381 
  (1858) 
  ; 
  

  

  Giinth. 
  Cat. 
  Fish. 
  viii. 
  p. 
  507 
  (1870) 
  ; 
  Jord. 
  & 
  Everm. 
  Bull. 
  U.S. 
  

  

  Nat. 
  Mus. 
  xlvii. 
  1896, 
  p. 
  11. 
  

   Ichthyomyzon 
  hirudo, 
  Girard, 
  t. 
  c. 
  p. 
  382; 
  Giinth. 
  /. 
  c. 
  

  

  Supraoral 
  lamina 
  tricuspid; 
  some 
  of 
  the 
  lateral 
  labial 
  

   teeth 
  bicuspid; 
  infraoral 
  lamina 
  with 
  7 
  to 
  12 
  cusps. 
  

   Mississippi. 
  

  

  * 
  I 
  cannot 
  see 
  that 
  the 
  larva 
  described 
  by 
  Kirtland 
  as 
  Ammoccetes 
  

   concolor 
  differs 
  in 
  any 
  way 
  from 
  that 
  of 
  Lampetra 
  planeri. 
  

  

  