LIST OF ILLUSTRATIONS. 



Plate I. Fig. 1. Pahenionetes esilipes, (p. 041;) from Lake Erie, lateral vievr, enlarged 

 two diameters. By J. H. Emertoa. 



Fig. 2. Mysis relicta, (p. 642 ;) female, from Lake Superior, lateral view, enlarged 

 about five diameters. By S. I. Smith. 



Fig. 3. Asellopsis tenas, (p. 659 ;) male, from Lake Superior, dorsal view, en- 

 larged four and a half diameters. By J. H. Emerton. 



Fig. 4. Asellus communis, (p. 657 ;) male, from New Haveu, Conn., dorsal view, 

 enlarged two and a half diameters. By O. Harger. 

 Plate II. Fig. 5. Pontoporeia Hoyi, (p. 647 ;) female, from Lake Superior, lateral view, 

 enlarged ten diameters. Drawn by S. I. Smith. 



Fig. 6. Gammarus linmsens, (p. 651 ;) male, from Lake Superior, lateral view, 

 enlarged four diameters. Drawn by J. H. Emerton. 



Fig. 7. The same ; dorsal view of the posterior part of the abdomen, showing 

 the arrangement of the spines and the form of the telson, enlarged 

 twelve diameters. Draw^u by S. I. Smith. 



Fig. 8. Hyalella dentata, (p. 645 ;) male, from Madison, Wis., lateral view, 

 enlarged twelve diameters. By J. H. Emerton. 



Fig. 9. The same ; female, anterior portion. By J. H. Emerton. 



Fig. 10. The same ; male, telson and one of the posterior caudal stylets, dorsal 

 view, enlarged sixty diameters. By S. I. Smith. 



Fig. 11. Daphnia galeata, (p. 695 ;~; lateral view, enlarged about forty diame- 

 ters. By S. I. Smith. 



Plate III. Fig. 12. Leruseopoda fontinalis, (p. 663 ;) female, enlarged four diameters ; 

 a, lateral view ; &, dorsal view. Drawn, by J. H. Emerton. 



Fig. 13. The same; lateral view of the head, much enlarged; a, mouth; 1), 

 palpus-like appendage; c, autenuula"; d, antenna. Drawn by S. I. 

 Smith. 



Fig. 14. The same ; a, prehensile maxilliped of the right side, seen from be- 

 neath, enlarged fifty diameters ; &, one of the mandibles, enlarged 

 three hundred and fifty diameters. Drawn by S. I. Smith. 



Fig. 15. Lernajopoda siscowet, (p. 664;) female, enlarged four diameters; a, 

 lateral view ; h, dorsal view. Drawn by J. H. Emerton. 



Fig. 16. The same ; a, one of the mandibles, enlarged one hundred and seventy- 

 five diameters ; h, prehensile maxilliped of the left side, seen from 

 beneath, enlarged twenty-five diameters ; V , palpus-like appendage 

 upon the penultimate segment, enlarged fifty diameters. Drawn by 

 S. I. Smith. 



Fig. 17. Leruieopoda (?) coregoni, (p. 664 ;) a, prehensile maxilliped of the right 

 side, seen from beneath, enlarged about twelve diameters ; a', tip of 

 the same, enlarged about twenty-five diameters ; & and c, mandi- 

 bles, enlarged one hundred and seventy-five diameters. Drawn by 

 S. I. Smith. 



Fig. 18. Phrygaueidse, (p. 694 ;) larva, removed from its tube, lateral view, 

 enlarged six diameters ; a, outline of the tube, natural size. Drawn 

 by J. H. Emerton. 



Fig. 19. The same ; dorsal view. Drawn by J. H. Emerton. 



S. Mis. 74 50 



