EXPLANATION OF PLATE XXI. 



106. Pleurotoina bicarinatum, (p. 638;) natural size. 

 107. Bela plicata, (p. 637 ;) natural size. 

 108. Bela harpularia, (p. 636;) natural size. 

 109. Anachis similis, (p. 644 ;) natural size. 

 110. Astyris Innata, (p. 645;) enlarged. 

 111. Astyris zonalis, (p. 645 ;) enlarged. 

 112. Tritia trivittata, (p. 641 ;) natural size. 

 113. Ilyauassa obsoleta, (p. 641 ;) natural size. 

 114. Nassa vibex, (p. 640 ;) natural size. 

 115. Neptunea pygma-a, (p. 639 ;) natural size. 

 116. Urosalpiux cinerea, (p. 641 ;) natural size. 

 117. Eupleura caudata, (p. 642;) natural size. 

 118. Purpura lapillus, (p. 642;) natural size. 

 119. The same ; banded variety. 

 120. The same ; egg-capsules, enlarged one-third. 

 121. Bucciuum uudatmn, (p. 638;) natural size. 

 122. Scalaria nmltistriata, (p. 660;) enlarged. 

 123. Scalaria lineata, (p. 660;) enlarged. 



(Figure 120 was drawn from nature by J. II. Emerton ; the rest are 1'rora Binney's Gould, drawn by 

 E. S. Morse.) 



