ORTMANN: THE CRAWFISHES OF THE STATE OF PENNSYLVANIA 375 
The specimens from the Lake Erie drainage in Conneaut Creek quite often have 
two spines (eight specimens out of twenty-two), and thus correspond to the Beaver 
River form, and to those from Elk Creek, in which one specimen out of six has two 
spines. Thus it appears that the form in the drainage of Lake Erie more closely 
approaches the form found in the Beaver River than that found in French Creek, 
although it must be granted that the material at hand seems to be not entirely 
satisfactory, being somewhat too scanty from French Creek, and decidedly insuf- 
ficient from Elk Creek. 
A few freaks have come under observation in the following cases : 
1. As has been said, the rostrum reveals in old individuals a tendency to a 
shortening of the acumen. The extreme is reached in a specimen (male of-the first 
form) 74 mm. long, from Conneaut Outlet, Crawford County (D. C. Hughes coll.), 
where the acumen is broadly triangular and hardly longer than the short marginal 
spines, reaching only to the distal end of the basal joint of the peduncle of the 
antennula. The acumen is well formed (not deformed), showing no traces of injury. 
But that this specimen undoubtedly has been injured at some time earlier in its life, is 
revealed by the fact that both claws are comparatively small, and bythe characters 
of regeneration (lack of spines on the outer lower margin of the meropodite, the 
absence of a tubercle on the anterior margin of the lower side of the carpopodite, 
and the generally weak and slender shape). 
2. A female (46 mm. long) from Brokenstraw Creek, Garland, Warren County, 
has the acumen of the rostrum directed obliquely to the left side, and the right 
margin of the rostrum has five marginal spines. This seems to be due to an injury 
received in earlier life. The left claw is also smaller and of the regenerated type. 
3. A specimen (55 mm. long) from the Alleghany River at Sandy Creek (col- 
lected by the writer, Noy. 19, 1904, Cat. No. 74. 479), has the characters of a female 
in the shape of the chele and the lack of hooks on the pereiopods. The annulus 
ventralis, however, is very indistinct, although its outlines and slight median 
depression are visible, as is also the median fissure. But this individual has the 
male genital opening in the coxopodite of the fifth pereiopod, and the first pleopod 
is of the male type, although small; it is unusually short, reaching only to the 
anterior margin of the coxopodites of the fourth pereiopods ; it is of the type of the 
first form, with a distinct shoulder; the outer part is horny and distinctly longer 
than the inner part. ‘The second pleopods are entirely of the male type. Accord- 
ing to the sexual orifice and the copulatory organs, we are to regard this as a male 
with certain female characters. 
4. A pendant to the last specimen is one (67 mm. long) from the Ohio River, 
