152 MARINE AND FISHERIES 



5 GEORGE v., A. 1915 

 Eucrangonyx gracilis (Smith). Fig. 4, c. 



Crangonyx gracilis^Smith, 1871, p. 453; 1874, p. 654. 



(?) Crangonyx (?) sp. Nicholson, 1873, p. 501. 



Eucrangonyx gracilis Weckel, 1907, p. 32. 



This species does not appear to be very common. It is found in shallow 

 water among weeds and down to 13 fathoms (Smith). According to Weckel 

 it ranges from Rhode Island to Wisconsin. 



Localities. — Lakes Superior, Michigan and Huron (Smith and Weckel). 



Georgian Bay: Go Home (R); Shawanaga (Wo). 



Bond Lake (near Toronto). 



Stomach of Mud-minnow {Umbra limi) (Forbes). 



This species is well characterized by the features mentioned in the keys and 

 by the figure. Among other things it can be distinguished from the two species 

 of Gammarus, which it very much resembles, by the absence of stout bristles on 

 the dorsal surface of the abdomen and by the structure of the secondary flagellum 

 of the antennule, which consists of two joints, the last one very short. 



Length up to 18 mm. 



Hyalella knickerbockeri (Bate).' Fig. 4, d. 



H. dentata Smith, 1874, p. 645. 



H. knickerbockeri Weckel, 1907, p. 54; Jackson, 1912. 



This species is extremely abundant among weeds in shallow water, both in 

 the Georgian Bay and in Lake Ontario. Smith reports it from Maine to Wisconsin 

 on the north. 



Localities. — Lakes Superior and Michigan (Smith and Weckel). 



Georgian Bay: Go Home (C and R); Matchedash Bay (R); Waubaushene, 

 Shawanaga, French River, Killarney, Tamarac Bay (Manitoulin Id.), Fitzwilliam 

 Id. (Wo). 



Lake Ontario: Toronto. 

 "Stomachs of the following fishes according to Forbes (1888), — Perca flavescens, 

 Percina caprodes, Micropterus dolomieu, Eupomotis gibbosus, Lepomis pallidus, 

 Ambloplites rupestris, Aphredoderus sayanus, Fundulus diaphanus, Notropis cor- 

 nutus, N. heterodon, Ictalurus punctatus, Ameiurus natalis, A. nebulosus, Amia 

 calva and Polyodon spathula. . 



This species is easily recognized by the exceedingly broad and clumsy hands 

 of the second gnathopods of the male, by the absence of a secondary flagellum 

 on the antennule and also by the spines projecting backward from the middle of 

 the posterior margin of each of the first two abdominal segments. Weckel includes 

 in this species forms without these spines. In my material I have not seen any 

 individuals without them. Length up to 7 mm. 



Order MYSIDACEA. 

 Of this group only a single species occurs within our limits. 



