PLATE I. 



FIGURE 1. PMloscia vittata Say (p. 306); dorsal view, enlarged sis diameters; 

 natural size indicated by cross at the right. 



2. Scyphacella arenicola Smith (p. 307) ; dorsal view, enlarged about twelve 

 diameters; natural size indicated by cross at the right. 



3. Actoniscus ellipticus Harger (p. 309) ; dorsal view, enlarged ten diame- 

 ters; natural size indicated by line at the right. 



4. Jgera albifrons Leach (p. 315) ; female ; dorsal view, enlarged about ten 

 diameters. 



5. The same ; maxilliped from the left side, exterior view, enlarged twenty- 

 five diameters ; P, palpus ; I, external lamella. 



6. The same ; maxillae, enlarged twenty-five diameters ; a, outer, or second, 

 pair of maxillse; &, inner, or first, pair of maxillae; i, inner, e, outer 

 lobe. 



7. The same ; inferior surface of the pleon of a female. 



8. The same ; inferior surface of the pleon of a male. 

 (All the figures were drawn from nature by O. Harger.) 



