OKTMANN: THE CRAWFISHES OF THE STATE OF PENNSYIA'AN'IA 425 



B. Geogkai'hical Distribution. 



(Plates XLII and XLIII.) 



1. Camharus lirao.fus. 



a. Summarji of Facts (see above, pp. 35G-358). 



This species belongs to the rivers, ponds, and canals of the lowlands of the At- 

 lantic (yoastal Plain and tlie Piedmont region *" in the states of New Jersey, Penn- 

 sylvania, Maryland, District of ("olumbia, and Virginia. It has not been reported 

 from the State of Delaware, but must certainly occur there also. 



In Pennsylvania it extends up the rivers to a certain distance and in the Sus- 

 quehanna iviver enters the Alleghany Mountain region. In Maryland it goes up 

 i\w i'otonuic River, reaching the eastern extremity of West Virginia, thus also en- 

 ti'i-jng tlie Alleghany Mountain region. 



Thus it is found in Pennsylvania in the drainages of the Delaware, Susque- 

 hanna and Potomac Rivers ; but it decidedly prefers the region of the lower Dela- 

 ware, from the bend of the river at Trenton downward. Here it is exceedingly 

 abundant, as also in the lower and quieter parts of the Schuylkill River at Philadel- 

 phia. It goes up the Delaware and Schuylkill, and is found in their tributaries 

 within tlie Piedmont region, but here it is by no means as abundant as in the Dela- 

 ware. It seems to be absent in the great Alleghany Valley between the Susque- 

 hainia and the Delaware, but reaches the foot of the Blue Mountain between the 

 Su.squehanna and Potomac, occupying the Cumberland \^illey (part of the great 

 Alleghan}' Valley), and in the Susquehanna and Juniata it a^scends even further, 

 far into the Alleghany Mountains (Center and Bedford Counties). 



h. OrUi'iii of the distribution of C. limosus. 



III. J'cii.nsi/lraitia. 

 ill the Delaware Kiver al)ove Trenton this species goes up as far as Nrw IIo|)e 

 in lUuks ('i)unty; but is very rare there, (only one specimen was secured liy tiie 

 writer after a prolonged search), and it seems that it does not go far lieyond tliis 

 point, if at all. Professor A. E. Davison informs me that it is not found near 

 Easton, North^impton County, about ten to lifteen miles from the Blue Mountain, 

 and I was unable to find it in the Little Lehigh Creek lu'ar Emaus, Lehigh Coinity. 



•"As to tlie division of Pennsylvania into Cnastnl Plain, Pinlmnnl Plttlrnii, GrrnI Allfi/hnny f llry. ilhi/hnnii .l/.m..- 

 (dins nn<l Alleghany I'laliaii, see Davis, I8S9, p. I><7, an<l IIolli«t(T, IOm), j, |o, niiip. Fit; I • lUn |'.iw,-ll l-(ii'. j. 

 13ei seq. nncl map, and Willis. lU9ii, p. I(i9. 



