362 MEMOIRS OF THE CARNEGIE MUSEUM 



General color, oUve-grccn (Ridgway, 1886, X, 18), sides of carapace cream-color 

 (VI, 20). A rufous (IV, 7) spot on anterior margin of carapace. Lower side 

 whitisli. Anterior half of abdominal segments hazel (IV, 12). Chelte olive-yelhw 

 (VI, 16), mottled with olive-green. Finger tips oranrje (VI, 3), followed proximally 

 by a citron-yellow (VI, 15) band. One rufous articular tubercle above on the baud. 

 Articular membranes of hand lake-red (Vll, 2). Finger tips of chelte of second and 

 tbird pereiopods, and dactylopodites of fourth and fifth pcreiopods orange. Pereio- 

 pods pale brownish-white, mottled and niarlded with olive-yt'llow. Antennal Hag- 

 elluni annulated oli re-green and nvhracrous (V, 7). Spines on sides of carapace and 

 rostrum buff (V, 13). Antennal scale olive-i/ellow, its center olive-green. 



It is to be remarked that in this specimen no dark olive-green band is found 

 near the finger-tips. The same was the case generally in specimens from Temple 

 Creek, Albion, and from Elk Creek (all collected in autumn). However, specimens 

 from Conneautville Station, Crawford County, collected in June, generally bad a 

 dark green, almost black band, succeeding the pale band. A similar dark Ijand 

 ajjpeared in some of the Temple Creek specimens, after they had been preserved 

 for some time in alcohol, but it disappeared again with tbe progress of the bleach- 

 ing action of the preserving fluid. In collecting the specimens of this species and 

 of C. obscurus in Erie County in October, 1904, I was generally able to distinguish 

 the two species, where they were found associated, by the color of the finger tips. 

 However, too much reliance should not be placed upon this character, since I was 

 not subsequently able to test this observation. 



The description of this species, as given above, is drawn from si.\tv-one speci- 

 mens preserved in the collection of tbe Carnegie Museum. Of these, fifty-three are 

 from the State of Pennsylvania (forty-eight from streams flowing into Lake Erie, 

 five from tbe lake itself). One specimen is from Lake Erie, Erie County, Ohio, and 

 seven are from the northern parts of ^Michigan. 



DISTRIBUTION (see Plate XLll, Fig. 3). 

 LOCALITIES REPRESENTED IX THE CARNEGIE MUSEUM. 



Pennsylvania: Erie Couufg, Lake Erie, Presque Isle, (1). A. Atkinson coll.); 

 Lake Erie, Miles Grove ; Walnut Creek, Swanville ; Elk ( 'reek, Girard ; Elk Creek, 

 Miles Grove; ('onneaut Creek, Albion; Temple Creek, Albion; (^'rairfanl Cuuntg. 

 tributary of Conneaut Creek, Conneautville Station. 



Ohio : Erie (_'(/unlij, Lake Eiie, Cedar Point, near Sandusky, (O. E. Jennings 

 coll.). 



Michigan: Enrmd (hvniji, Crooked Lake, Oden near Petoskey, (E. B. William- 

 son coll.). 



