ORTMANN: THE CRAWFISHES OF THE STATE OF PENNSYLVANIA 387 



Fayette. All of these are west of the Chestnut Ridge. East of the (.'hestnut Rulge. 

 but west of the Alleghany Front, specimens over 80 niin. in length are rare; only 

 one was found at Saml Patch, Somerset County, (86 mm. long). Specimens over 

 70 mill, in Icnutli ai-e not infrequent here. In the .\llegliany .Mountain region, 

 (between the Alleghany Front and the Blue Ridge) only a few instances of speci- 

 mens over 70 mm. in length iiave been found, and none as large as 80 ram. The 

 largest is from Mc(Jonnelsburg, Fulton County, 77 mm. East of the Blue Ridge 

 (South Mountain) the length 70 mm. is never attained. In the easternmost extrem- 

 ity of the state (Xortliampton and Bucks Counties) even the length of GO mm. is 

 not represented among my material, although I possess large series of specimens 

 from this region. Thus it appear.s that the size gradually decreases from west to 

 east. There is hardly any appreciable decrease in .size from south to noi-th. The 

 smaller number of large individuals from the northwestern section of the state is 

 very likely due to the fact that large collections were not made in that part of the 

 state. 



Freaks have been observed in several cases. Aberrant forms of the rostrum 

 have been repeatedly found, atid one variation has been encountered four times in 

 which the rostrum has a very slightly developed acumen, so that it is almost evenly 

 rounded off anteriorl}', witli only a small and indistinct median angle or point, 

 (female, 2-5 mm., Schenley Park, Pittsburgh ; female, 50 mm., Templeton, Arm- 

 strong County ; male, first form, (34 mm., Branchton, Butler County ; female, 80 mm., 

 MoiKjngahela City, Washington County). The rostrum, in these cases, is exception- 

 ally short, due to a reduction of the acumen. A case of an unsymmetrical rostrum, 

 with the left angle at the base of the acumen cut off, has also been observed ; this 

 is clearly a malformation due to some previous external injury. 



We may class with the freaks a single specimen in which the carapace possesses 

 a lateral spine. The specimen is a female (42 mm. long) from Weskit, Armstrong 

 County, and it has a small, sharp, lateral spine, but only on the left side of the 

 carapace. This is the more remarkable since it demon.strates the importance of this 

 specific character. There is not a single other individual among tiie large material 

 at hand which possesses such a spine, although granulations in its place are not 

 infre([uent. 



Two interesting cases of aljnormally developed sexual characteristics have been 

 noticed (compare the other ca.ses mentioned under C (Fa.ro)iiits) o/wtvnv/.v). 



1. A large female, 71 mm. long, found March 31, 1905, at llollidays C»)ve. Han- 

 cock County, W. Va., (Cat. No. 74. 491), which is normal in every respect l)Ut one. 

 antl be.sides, is undoubtedly sexually normal, since it carried under the abdomen 



