CONTKXTS. 



I'Ai.i;. 

 I. iNTKODirnoN : Scoi'K 1)1' W'nllK ; .MlCTlIODS ; AcKNOWr.EDGMEXTS .'MS 



II. HisToiucAi. Review of our Systematic K.NowLEiifiE of the Crawfishes of 



Pennsvevaxia 348 



III. -MoRpiioMXJY AND C'horoi.o(;v of the Pe.nnsyi.vania Species ."^.^O 



.1. General Remarks oSO 



/>. Key for tiie Pennsylvania species 351 



C, De.scription and Distribution of the species 352 



1. Cambarus (Faxoniiis) limosus (Raf.) 352 



2. Caiiiharus (Faxonins) propin(|uns (iir 358 



'2a. Cambarus (Faxonius) propin(jnns sanljorni (Fax.) (cxlraliniital) 3G5 



3. Camharus (Faxonius) obscurus Hag 369 



4. Cambarus (Bartonius) bartoni (F.) 377 



Ad. Cambarus (Bartonius) bartoni robustus ((jir.) 388 



5. Cambarus (Bartonius) carolinus Er 394 



(I. Cambarus (Bartonius) monongalensis Ortni 398 



7. Cambarus (Bartonius) diogenes Gir 402 



IV. EcOEOdV A.ND GeOGRARHICAE DISTRIBUTION 410 



-1. Ecology 410 



1. The River-S])ecies : C. limosus, pr()pin(iuus, obscurus 410 



2. The Mountain-Stream Species : C. bartoni 4 I ."! 



•">. The Burrowing Species : C. carolinus, monongalensis, diogenes 41 (J 



II. General Habitat 4 1 (5 



'6. Shape of Burrows . . . . , 418 



r. Constniction of IJurrows 419 



B. Geographical Distribution 425 



1. Cambarus limosus ; . -125 



II. Summary of facts 425 



h. Origin of distribution 425 



2. Cambarus propinquus, stinborni, and obscurus 433 



a. Summary of facts 433 



b. Origin of distribution 434 



3. Cambarus bartoni 447 



II. Summary of facts ' 4 47 



iii 



