KEY TO THE SPECIES OF THE SUBGENUS PENNIDES

1.     Basis of cheliped with spine on mesial surface (Fig. 53a; see also Fig. 54a):...................................
        ...................................................................................................  Procambarus (Pe). versutus  (Hagen, 1870).

       (Streams from western Alabama to the Apalachicola River in Florida.
        Literature: Hobbs, 1942d).

• Basis of cheliped without spine on mesial surface (Fig. 53b):.................................................................  2

2(1).   First pleopod with distinct angular shoulder on cephalic surface (Fig. 54b):..................................
           .................................................................................  Procambarus (Pe.) lylei  Fitzpatrick and Hobbs, 1971

       (Tributaries of the Yalobusha River in Calhoun County, Mississippi.  Literature:
        Fitzpatrick and Hobbs, 1971).

• First pleopod without distinct angular shoulder on cephalic surface (Figs.  54c-i, 55):........................  3

3(2).  Cephalic process of first pleopod well developed (Figs.  54c-i, 55a, b):...............................................  4

• Cephalic process of first pleopod absent or rudimentary (Fig. 55c-g):.................................................  11

Fig. 53.  Ventral view of basal portion of left pereiopods.  a, Arrow indicating spine on basis of first pereiopod (cheliped);  b, First pereiopod lacking spine on basis.

4(3).   Cephalic process of first pleopod situated entirely mesial to central projection and completely
           obscured by latter in lateral aspect (Fig.  54c, d):...............................................................................
           ...................................................................................................  Procambarus (Pe.) suttkusi  Hobbs, 1953.

       (Tributaries of the Choctawhatchee River in Alabama and Florida.  Literature:
         Hobbs, 1953b, 1962).

• Cephalic process of first pleopod situated cephalic, lateral, or cephalomesial to central
  projection, never entirely obscured by latter in lateral aspect (Figs. 54e-i, 55a,b):..............................  5

5(4).   Cephalic process of first pleopod subtruncate with acute angle caudodistally (Fig. 54e):..............
           ......................................................................................................  Procambarus (Pe.) vioscai  Penn, 1946.

       (Tributaries of the Red River in Arkansas and Louisiana eastward to the Pascagoula
        River in Mississippi.  Literature:  Penn, 1959;  Hobbs, 1962).

• Cephalic process of first pleopod tapering from base (Figs.  54f-i, 55a, b):.........................................  6

6(5).   Cephalic process of first pleopod directed caudodistally (Fig. 54h, i):.................................................  7

• Cephalic process of first pleopod directed distally (Figs. 54f, g; 55a, b):.............................................  8

Fig. 54.  a-c, e, g,  Lateral view of distal portion of left first pleopod;  d, Mesial view of same;  h, i, Lateral view of left first pleopods.  a, Procambarus versutus;  b, P. lylei;  c,d, P. suttkusi;   e, P. vioscai;  f, P. penni;  g, P. elegans;  h, P. echinatus;  i,  P. dupratzi.  (c, caudal process;  ck, caudal knob;  cp, cephalic process;  e, central projection;  m, mesial process.

7(6).   First pleopod with subapical setae abundant, no part of central projection evident in lateral aspect cephalodistal to cephalic process (Fig. 54i):..................................................................................................
....................................................................................................................  Procambarus (Pe.) dupratzi  Penn, 1953.

       ( Streams in the Trinity, Red, Neches, Sabine, and Calcasieu river systems in Texas,
         Arkansas, and Louisiana.  Literature:  Penn, 1956d;  Hobbs, 1962).

• First pleopod with subapical setae sparse; part of central projection evident in lateral aspect
  cephalodistal to cephalic process (Fig. 54h, note arrow):.................................................................
  ......................................................................................................  Procambarus (Pe.) echinatus  Hobbs, 1956.

       (Streams in the Edisto and Salkehatchie river systems in South Carolina.  Literature:
         Hobbs, 1956a, 1962).

8(6).   Cephalic and mesial processes of first pleopod in lateral aspect diverging at angle of at least
           50 degrees (Fig. 54f):............................................................................................................................
           ............................................................................................................  Procambarus (Pe.) penni  Hobbs, 1951).

       (Tributaries of the Pearl and Pascagoula rivers in southcentral Mississippi and Louisiana.
        Literature:  Penn, 1956b;  Hobbs, 1962).

• Cephalic and mesial processes of first pleopod in lateral aspect subparallel or diverging at
  angle of much less than 50 degrees (Figs. 54g, 55a, b):.............................................................................  9

9(8).  Cephalic process of first pleopod not reaching so far distally as caudal knob or caudal process
          (Fig. 54g):.....................................................................................  Procambarus (Pe.) elegans  Hobbs, 1969.

       (Streams in the Ouachita River system in northern Louisiana.  Literature:  Hobbs, 1969c).

• Cephalic process of first pleopod reaching farther distally than caudal knob or caudal process
  (Fig. 55a, b):.....................................................................................................................................................  10

10(9).   Central projection of first pleopod with cephalic margin rounded; caudal process small (Fig. 55a):....
              .......................................................................................................  Procambarus (Pe.) ablusus  Penn, 1963.

       (Streams in the Hatchie River system in Tennessee and Mississippi.  Literature:  Penn, 1963).

• Central projection of first pleopod with cephalic margin virtually straight; caudal process prominent
  (Fig. 55b):...............................................................................  Procambarus (Pe.) natchitochae  Penn, 1953.

       (Tributaries of the Red, Bayou Teche, and Calcasieu rivers in Texas, Arkansas, and Louisiana.
         Literature:  Penn, 1956b, 1959;  Hobbs, 1962).

11(3).   Distolateral surface of shaft of first pleopod with longitudinal excavation extending proximally
             from base of central projection (Fig. 55c):.........................  Procambarus (Pe.) lagniappe  Black, 1968.

       (Tributaries of the Tombigbee River in Kemper County, Mississippi.  Literature:  Black, 1968).

• Distolateral surfaces of shaft of first pleopod without such excavation (Fig. 55d-g):.................................  12

12(11).   Central projection of first pleopod arising from level distinctly proximal to base of caudal
                process (Fig.  55d, e):................................................................................................................................  13

• Central projection of first pleopod arising from level distinctly distal to base of caudal process
  (Fig.  55f, g):......................................................................................................................................................  14

13(12).   Caudodistal portion of shaft of first pleopod subtruncate with caudal element and central
                projection situated on cephalic 1/2 of tip (Fig. 55d):..........  Procambarus (Pe.) gibbus  Hobbs, 1969.

       (Streams in the Flint River system in southwestern Georgia.  Literature:  Hobbs, 1969c).

• Caudodistal protion of shaft of first pleopod tapering with caudal element and central projection
  constituting almost entire tip (Fig. 55e):............................  Procambarus (Pe.) spiculifer  (LeConte, 1856).

       (Streams from western Alabama to the Savannah River in Georgia.  Literature:  Hobbs, 1942b, 1962).

Fig. 55.  Lateral view of distal portion of left first pleopods.  a, Procambarus ablusus;  b, P. natchitochae;  c, P. lagniappe;  d, P. gibbus;  e, P. spiculifer;  f, P. ouachitae;  g, P. raneyi.

14(12).   Caudal knob of first pleopod conspicuous; caudal process broad and leaflike in lateral
                aspect (Fig. 55f):..................................................................  Procambarus (Pe.) ouachitae  Penn, 1956.

       (Tributaries of the Arkansas and Ouachita rivers in Arkansas and Mississippi.
         Literature:  Penn, 1956a;  Hobbs, 1962).

• Caudal knob of first pleopod vestigial; caudal process narrow and elongate (Fig. 55g):...........
  ..........................................................................................................  Procambarus (Pe.) raneyi  Hobbs, 1953.

     (Tributaries of the Savannah River in South Carolina and Georgia, and headwaters of the
      Ocmulgee River in Georgia.  Literature:  Hobbs, 1953c, 1962).

END OF PENNIDES

Last Updated:  10 September 2004