562 GEOLOGICAL SURVEY OF THE TERRITORIES, 
Tie 
' EXPLANATION OF PLATE XXIV. 
. 1. Estheria belfragei, edge of carapace, greatly enlarged, x ¢ Tolles, A. ocular 
. 2. Estheria jonesii, edge of shell, with a portion chipped off, x 4 A. 
. 3. Estheria mexicana, Ohio, X% A. 
. 4, Hstheria dawsoni (fossil). Drawn by L. Trouvelot. 
. 4a. Estheria dawsoni, showing the granulated ridges, x 4 A. 
. 4b. Estheria dawsoni, showing the pits between. the ridges. 
. 0. Hstheria californica, X4 A. 
. 6. Hstheria mexicana, Kansas, X 4 A. 
. 7. Lstheria morsei, lowa; edge of the shell. 
. 8. Estheria compleximanus, Kansas; edge of shell, x 225 diameter. 
. 9. Hstheria mexicana, section through the entire animal, through the front part 
of thorax; ant!, antenn; ani?, base of second antenn ; shg, section through 
the shell-gland; br’, upper, br’, lower division of the flabellum ; int, intes- 
tine; ng, nerve-ganglion ; 1-6, first to sixth endites. 
. 10. Estheria compleximanus. Section through the posterior part of the thorax, 
the shell haying been removed ; lettering asin Fig. 9; mus, dorsal mus- 
cles. 
All the figures, except Fig. 4 drawn by the author, 
