358 MEMOIRS OF THE CARNEGIE MUSEUM 
Co.; Susquehanna River, Northumberland, Northumberland Co.; Fishing Creek, 
Bloomsburg, Columbia Co.; Bald Eagle Creek, Milesburg, Center Co. ; Conoco- 
cheague Creek, Chambersburg, Marion, and Williamson, Franklin Co.; Maiden 
Creek, Maiden Creek, Berks Co. 
REMARKS. 
Cambarus limosus is the common river species of eastern Pennsylvania. Its 
morphological characters are very constant, and give it a rather isolated position 
within the genus, which is also expressed by, and very likely due to, its geograph- 
ical isolation, the most closely allied species being found far to the west, in Indiana 
and Kentucky, (see Ortmann, 1905), p. 114, 127). The most prominent specific 
characters are furnished by the male sexual organs, and the spinosity of the sides 
of the carapace. The description, as given above, does not indicate any important 
variations, and the specimens are generally very uniform. The spinosity of the 
carapace, however, changes with age, young specimens being much less spinose than 
old ones. In the spines of the chelipeds and of the anterior section of the telson, 
there is some variation, but this is only sight and not subject to any rule. The 
shape of the carapace and rostrum is very constant, the only differences of age no- 
ticed are found in the acumen of the rostrum, which in young specimens is slen- 
derer than in those which are older, and in the bulging out of the branchial regions 
of the carapace, which is most marked in old individuals. The changes in the 
pubescence of the whole body are apparently due to wear. The short hairs gener- 
ally present in newly moulted individuals slowly wear off, and specimens with a 
distinct coat of dirt upon them, indicating age, generally have the pubescence more 
or less, sometimes entirely, worn off. Only on the hands and fingers are traces of 
it left. 
I myself have never found any freaks in this species. But Mr. W. R. McConnell 
found a male (first form), 66 mm. long, at Bloomsburg, Columbia County, (the only 
specimen taken at this locality), in which the rostrum had two pairs of marginal 
spines. The additional pair in this specimen is smaller, and stands about midway 
between the normal pair and the base of the rostrum. 
2. CamBarus (FaAxontus) propinquus Girard. 
(Plate XX XIX, Fig. 6a and 6b.) 
Cambarus propinquus, Girard, 1852, p. 88 ; Hagen, 1870, p. 67, Pl. 1, f. 34-38, Pl. 3, f. 153; Smith, 1874, p. 638 ; Forbes, 
1876, p.4, 19; Bundy, 1877, p. 171 ; Bundy, 1882, p. 181; Bundy, 1883, p. 402; Faxon, 1884, p. 147 ; Faxon, 18851, 
p- 91; Faxon, 1885), p. 360; Underwood, 1886, p. 371 ; Faxon, 1890, p. 628; Hay, 1896, p. 497, Fig. 11; Ward, 
1896, p. 15 ; Faxon, 1898, p. 651; Hay, 1899, p. 960, 962 ; Ortmann, 1905a, p. 400. 
Cambarus (Faxonius) propinguvs Ortmann, 1505b, p. 112, 132. 
