EXPLANATION OF PLATE XXV. 
Figure 160.—Utriculus canaliculatus, (p. 663 ;) enlarged. 
161.—Bulla solitaria, (p. 662 ;) natural size. 
162.—Amphisphyra debilis, (p. 663;) enlarged. 
163.—Cylichna alba, (p. 664 ;) natural size. 
164.—Cylichna oryza, (p. 664 ;) enlarged. 
165.—Actzon puncto-striata, (p. 664;) enlarged. 
166.—Trachydermon ruber, (p. 662 ;) natural size. 
167.—Chetopleura apiculata, (p. 661;) natural size. 
168.—Alexia myosotis, (p. 662;) natural size. 
169.—Melampus bidentatus, (p. 662 ;) natural size. 
169a.—The same; banded variety, (p. 662;) natural size. 
170.—Doto coronata, (p. 665;) a, dorsal view, enlarged ; b, head, from above; 
c, one of the branchiz. 
171.—Elysiella catulus, (p. 668;) enlarged three diameters. 
172.—Elysia chlorotica, (p. 667 ;) enlarged two diameters. 
173.—Doridella obscura, (p. 664 ;) a, dorsal view ; b, ventral view, enlarged. 
174.—Montagua pilata, (p. 666;) natural size. 
175.—Hermea cruciata, (p. 667;) enlarged. 
176.—Doris bifida, (p. 664;) enlarged three diameters. 
177.—Cavolina tridentata, (p. 669;) natural size. 
178.—Styliola vitrea, (p. 668;) enlarged three diameters. 
(Figures 171, 172, 173, 174, 1 
175 by A. Agassiz; 176, by 
: were drawn from nature, by A. E. Verrill; 169a, 170 by E. 8. Morse; 
Binney's Gould, mostly by E. 
78 
H. Emerton ; 177 was copied from Cuvier, (last ill. ed.). Therest are from 
8. Morse.) 
