LIST OF ILLUSTRATIONS. 



Plate I. Fig. 1. Pal;priionetes exilipes, (p. 641 ;) from Lake Erie, lateral view, enlarged 

 two diameters. By J. H. Emerton. 



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

 about five diameters. By S. I. Smith. 



Fig. 3. Asellopsis tenax, (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 Haven, Conn., dorsal view, 

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

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

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



Fig. 6. Gamraarus limn:eus, (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 spinas and the form of the telson, enlarged 

 twelve diameters. Drawn by S. I. Smith. 



Fig. 8. Hyalella dentata, (p. 645 ;) male, from Madison, AVis., 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. Dapbuia galeata, (p. 695;") lateral view, enlarged about forty diame- 

 ters. By S. I. Smith. 

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

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



Fig. 13. The sams; lateral view of the head, much enlarged; a, mouth; b, 

 palpus-like appendage ; c, anteuuula ; 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 ; b, one of the mandibles, enlarged 

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



Fig. 15. Lern«opoda siscowet, (p. 664;) female, enlarged four diameters; a, 

 lateral yiew ; b, dorsal view. Drawn by J. H. Emerton. 



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

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

 beneath, enlarged twenty-five diameters ; b', palpus-like ap^iendage 

 upon the penultimate segment, enlarged fifty diameters. Drawn by 

 S. I. Smith. 



Fig. 17. Lernieopoda (?) coregoni, (p. 664 ;) a, j)rehensile maxilliped of the right 

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

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

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

 S. I. Smith. 



Fig. 18. Phryganeidaj, (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. 71 50 



