1 882.] Zoology. 241 



season was at hand, in fact they were evidently mating when 

 killed. I will add that a short time after Mr. Aldrich's visit I 

 obtained for the college museum a nest with eggs from that same 

 " little knoll " of which he speaks, while another nest was found 

 with young, which was very likely the one that he saw, which 

 may satisfy him that the bird had made no mistake. — F. E. L. 

 Beal, Ag. College, Ames, Iowa. 



Notes on some Fresh-water Crustacea, together with 

 Descriptions of two New Species (Continued). — Crangonyx 

 gracilis Smith. — (C. gracilis Smith S. L, Crustacea of the 

 Fresh-waters of the U. S., Report U. S. Fish Commission 

 for 1872-3, 654; S.A.Forbes, Bulletin Illinois Museum Nat. 

 Hist, No. 1, 6.) Numerous specimens of the Western variety of 

 this species were obtained in the ponds and slow streams around 

 Irvington during the winter and early spring of 1879-80. They 

 differ in no appreciable way from specimens of the same species 

 obtained at various localities in Illinois. 



Crangonyx mucronatits Forbes. — [C. mucrouatus Forbes, S. A., 

 Bull. Ills. Mus. Nat. Hist, No. 1, 6.) Two males of this curious 

 species were obtained from a well in Irvington during the latter part 

 of the year 1879. On the anterior edge of the sternal portion of 

 each of the last two thoracic segments, I have observed two ap- 

 pendages, no mention of which is made in the original description 

 cited above. They call to mind the appendages mentioned by 

 Prof. S. I Smith (op. cit 647) as occurring on some of the an- 

 terior segments of Pontoporcia hoyi. In form these appendages 

 are elongated, oval, and pointed. They are as long as the 

 ■ branchial sacs, of longer, and seem to be corneous. They may 

 occur on the sternal portion of other of the thoracic segments ; 

 but in the very few specimens that I have had the opportunity to 

 examine, I have not observed this. 



As e Hits communis Say. — (A. communis Smith, S. I., op. cit. 657 

 A. militaris Hay, O. P., Bulletin Ills. Mus. Nat. Hist, No. 2, 90.) 

 This species is very common in the streams about Irvington, 

 during the early months of spring. I am now pretty well con- 

 vinced that the form that I described as cited above is the same 

 as the Eastern species. It differs certainlv from Eastern speci- 

 mens in the armature of the hand, in the form of the genital 

 plates, in size, and in some other respects ; but I do not believe that 

 these characters are sufficiently marked and constant to enable us 

 to found species on them. The specimens obtained at Irvington 

 differ in the details of the hand and genital plates from all others 

 that I have seen; but these differences are accompanied by no 

 others of importance. As I now recognize this species, it extends 

 in its distribution from Massachusetts and Connecticut on the 

 east to the Mississippi on the west, and to Central Mississippi on 

 the south. About the middle of August of the present year I 



