EXPLANATION OF PLATE XXIII. 
Fiaure 125.—Crucibulum striatum, (p. 651;) natural size. 
126.—The same; side view. 
127.—Crepidula plana, (p. 650;) natural size. 
128.—C. convexa, (p. 650 ;) natural size. 
129.—C. fornicata, (p. 649 ;) natural size. 
129a.—The same; young specimen, 
130.—Neverita duplicata, (p. 646 ;) natural size. 
131.—Lunatia immaculata, (p. 646 ;) natural size. 
132.—Natica pusilla, (p. 647 ;) slightly enlarged. 
133.—Lunatia heros, (p. 646;) natural size. 
134.—The same; with the animal extended, as in crawling; dorsal view. 
135.—The same, variety triseriata, (p. 354;) young, natural size. 
136.—The same variety ; natural size, lower side. 
(From Binney's Gould, drawn by E. S. Morse.) 
