C54 REPORT CF COMMISSIONER OF FISH AND FISHERIES. 



Oil the inner edge. Divisions of the telson with a spine and one or two 

 hairs on the outer edge as well as a few spines and bairs at the tip. 



Length, from the front of the head to the tip of the telson, lO'""^ to 

 15-". 



This species is probably common throughout the Northern States. It 

 is abundant in the fresh-water streams and ponds about Isew Haven, 

 Conn. ; Say's specimens were from near Philadelphia ; Professor Yerrill 

 has collected it at Eastport, Me. ; Mr. N. Coleman, at Grand Rapids, 

 Mich. ; and Mr. J. W. Milner has found it in abundance at Ecorse, Mich. 

 Specimens collected at Madison, Wis., by Professor Yerrill, and at 

 Waukegan, 111., by Mr. Milner, are considerably larger than usual, and 

 differ slightly in the number of spines upon the hands, but apparently 

 belong to this species. 



Fragments of a Gammarus from the stomachs of shad taken in the Dela- 

 ware Kiver appear to belong to this species. 



? Gammarus minus Say. 



Journal Academy Nat. Sci. Philadelpliia, vol. i, p. 376, 1813; Bate, Catalogue 

 Ampbipodous Crustacea British Maseum, p. 221, 1862. 



I have not yet been able to rediscover this species, which is very 

 likely not a true Gammarus, and, as it seems to have given rise to much 

 confusion, I quote the original description : "Body whitish, with a few 

 pale fulvous lateral spots; eyes reniform, blackish, placed at the ex- 

 terior base of the superior antennse ; superior antennae obviously longer 

 than the inferior ones ; seta [secondary flagellum] short, attaining the 

 tip of the second articulation of the terminal joint [flagellum;] terminal 

 joint with about twelve articulations. Length, three-twentieths of an 

 inch, [nearly 4™"".] Found in brooks under stones, and may be readily 

 discovered by taking a stone out of the water, and inspecting its inferior 

 surface." 



According to Bate, specimens sent to the British Museum as this 

 species by Say, agree in no way with the description, and are described 

 by Bate as a species of J-^Zorc/^es/es,* although he quotes the " Gammarus 

 minimus Say," of White's List of Crustacea in the British Museum under 

 Gammarus minus, while White must have had the same specimens which 

 afterward became the types of the new species of '■'■Allorchestes.'''' The 

 Gamtnarus minus of DeKay (Natural History of New York, p. 37, pi. 9, 

 fig. 29) is made up principally of Say's original description ; but he ap- 

 parently had before him some other species, (probably small specimens 

 of G.fasciatus,) from which the rude attempt at a figure given in his work 

 may have originated. 



CrANGONYX GRACILIS Smith. 



American Journal of Science, 3(1 series, vol. ii, p. 453, 1371 ; and Preliminary 

 Report on Dredging in Lake Superior, p. 1022, 1871. 



Female. — Eyes slightly elongated, composed of a few black facets. 



* A. Knickerbockeri. See p. 647. 



