82 
John E. Cooper and Martha Riser Cooper 
Table 2. Data for six laden female Orconectes ( P .) carolinensis, new spe- 
cies, collected at the same site on 6 May 1981. 
TCL (PCL) 
Condition 
17.1 (11.5) 
28 ova (1.8-1. 9 mm diam) 
19.5 (13.7) 
59 ova (1.7-1. 9 mm diam), 3 of them 
beginning eclosion, and several empty egg cases 
20.4 (14.3) 
76 ova (1.7-1. 8 mm diam) 
21.2 (14.9) 
29 first-instar young and 1 unhatched ovum 
23.8 (16.7) 
16 first-instar young and 60 ova (1. 9-2.0 mm diam) 
undergoing eclosion 
25.3 (18.0) 
109 first-instar young and 2 unhatched ova 
lobiform cephalolateral prominences overhanging fossa and separated 
by deep trough) are typical of subgenus Procericambarus (Fitzpatrick 
1987:57-58). However, the upper limit of the range for length of 
the terminal elements of the mature gonopod, expressed as percent 
of total length of the appendage, is slightly higher for O. carolinensis 
(range = 46.5-57.9% * = 51.6%, n = 54) than for the subgenus (range 
= 34-55%). In addition, the range for areola length, expressed as 
percent of TCL, is considerably lower for O. carolinensis (range = 
25.5-31.1%, x = 28.5%, n = 113) than for the subgenus (range = 
29-37%). Within Procericambarus , O. carolinensis clearly has its greatest 
affinities with several members of the Spinosus Group, as defined 
by Fitzpatrick (1987:58). Its closest relatives almost certainly are 
Orconectes (. Procericambarus ) spinosus (Bundy), of the Tennessee and 
Coosa river basins, and Orconectes (Procericambarus) putnami (Faxon), 
which occurs in parts of the Ohio River drainage. 
The new species may be distinguished from its relatives in the 
Spinosus Group by the following: (1) the greater length of the terminal 
elements of the mature gonopod (range for the Spinosus Group is 
40-48% of total gonopod length); (2) the shorter, broader areola, and 
the greater number of punctations across the narrowest part; (3) the 
somewhat longer acumen and rostrum, the latter being deeply excavate, 
much more punctate and setiferous, and with thicker margins; (4) the 
smaller size (see section on “Size” for data); (5) the lack of a clearly 
defined ventral row of tubercles subtending the row on the mesial 
margin of the palm; (6) fewer tubercles in the ventralmost and dorsalmost 
rows of the mesial margin of the dactyl; (7) the far greater number 
of spiniform tubercles on the ventrolateral ridge of the merus, these 
being generally strong, acute spines, especially in the distal half to 
