EXPLANATION OF PLATE XXV. 



FIGURE 160. Utriculus caualiculatus, (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. Acta?on puncto-striata, (p. 664 ;) enlarged. 

 166. Tracbydermon ruber, (p. 662 ;) natural size. 

 167. Chretopleura 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; fc, bead, from above; 



c, one of the branch !;<>. 



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. Moutagua pilata, (p. 666;) natural size. 

 175. Herma-a 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, 178 wore drawn from nature, l>y A. E. Yerrill ; 169a, 170 by E. S. Morse; 

 175 by A. Agassiz ; 17(5, by J. H. Eraerton ; 177 was copied from Cuvier. (last ill. ed.). Tlie rest are from 

 Binney'a Gould, mostly by E. S. Morse.) 



