DESCRIPTION OF THE PLATES. 



PLATE IV. 



Exhibits the osteology of the Mastodon entire, with the tusks as found on 

 the same skeleton. 



PLATE V. 



WHEAT INSECTS, AND THEIR ANATOMY. 



Fig. a. Kernel of wheat, with its husks, and the worms feeding upon its 

 pulp. m 



Fig. b. Pupa greatly magnified. 



Fig. c. Wheat-head, with the chaff bent down by the yellow-bird, in 

 getting at the worms leaving the grain, as at * * *. 



Fig. e. Male antenna. 



Fig. / Ovipositor when drawn out, with three segments of the abdomen. 



Fig. g. Leg of the insect, showing its joints, greatly magnified. 



Fig. h. Female antenna magnified. 



Fig. i. Insect in its natural size. 



Fig. 1. Clear-winged wheat-fly. 



Fig. 2. Spotted-winged wheat-fly. 



Fig. 3. Cecidomyia tergata. 



Fig. 4. Male of the Clear-winged wheat-fly. 



Fig. 5. Cecidomyia thoracica. 



Fig. 6. Insect at rest, with its wings in their natural position. 



