348 MEMOIRS OF THE CARNEGIE MUSEUM 
Very considerable help was received from the Department of Agriculture in 
Harrisburg. The State Zodlogist, Professor H. A. Surface, not only sent to me for 
inspection all the crawfishes in the collection under his charge, but also submitted 
to me material collected during the summer of 1905 by Mr. W. R. McConnell, who 
was in charge of a survey conducted by the State Zodlogist in cooperation with the 
Commissioner of Fisheries, Mr. W. E. Meehan. To Mr. Meehan and Professor Sur- 
face I am under special obligation for giving instructions to Mr. McConnell regard- 
ing the collecting of crawfishes, and to the latter gentleman for carrying these out 
in the most thorough way in parts of the state not visited by myself. 
Finally, I was granted the privilege of examining the collections of the Academy 
of Natural Sciences in Philadelphia, where I found, aside from older specimens 
already used by Hagen and. Faxon, valuable additional material, collected by 
Messrs. H. A. Pilsbry, E. G. Vanatta, H. W. Fowler, and B. W. Griffiths. I also 
received specimens for examination from Oberlin College, through the late Pro- 
fessor A. A. Wright and Mr. R. L. Baird; from the New York State Museum 
through Mr. F. C. Paulmier; and from Dr. P. R. Uhler in Baltimore, and Professor 
T. D. A. Cockerell, in Boulder, Colorado. 
Last, but not least, my thanks are due to the Director of the Carnegie Museum, 
Dr. W. J. Holland, who not only granted the means for carrying on my work suc- 
cessfully, but has devoted much time to the editorial revision of the manuscript, 
and helped me in the preparation of the colored plates accompanying this memoir, 
which were made under his direction. 
Il. Hisrortcan REvIEw oF ouR SysTEMATIC KNOWLEDGE OF THE CRAWFISHES 
OF PENNSYLVANIA. 
The first species of the genus Cambarus ever described very likely came from 
our state. Astacus bartom of Fabricius (1798, p. 407) was sent to its author by Pro- 
fessor B. Smith Barton, who lived in Philadelphia, (see Faxon, 1885a, p. 65) and 
presumably was collected in the neighborhood of that city. 
The next record of a Pennsylvanian crawfish is given by Rafinesque (Nov., 1817), 
Astacus limosus, from the muddy banks of the Delaware near Philadelphia. An- 
other species mentioned by Rafinesque from this state, Astacus fossor, is not recog- 
nizable. Astacus limosus from the Delaware River was described a month later 
(Dec., 1817) by Say under the name of Astacus affinis. 
Harlan (1835) mentions A. bartoni from the vicinity of Philadelphia, and this 
record makes Philadelphia the type-locality of this species. 
Girard (1852) gives the following new localities in Pennsylvania: Cambarus 
