LIST OP ENGRAVINGS. XXi 



Fig. 



81 Medusa Pulmo, (Maori) . , . . . rS 



82 Beroe ovatus, (Bruguiere) • • • . 144 

 SZ Beroe pileus, {vi\,) j^ 



84 Velella limbosa, (Guerin) .... 144 



85 Phijsalia atlantica, (id.) . . . ^ .144 



86 Actinia rvfa, (original) ..... \/^a 



87 Ditto expanded, (original) .... 145 



88 Asterias serrulata, (Bruguiere) .... 147 



89 Asterias regularis, (id.) . . • . ^ -i/Vl 



90 Echinus Ananchites ovata, (id.) .... 147 



91 Clypeaster rosaceus, (id.) ..... 147 



92 Ophiura lacertosa, (id.) ..... 147 



93 Euryale muricatum, (id.) . . . ^ 24^ 



94 Pentacrinus europa^us, (Thomson) . . .147 



95 Ambulacra, and feet o^ Asterias, viewed from the under side, 



(Reaumur) ' 148 



96 Ditto, viewed from the upper side, (id.) . . .148 



97 Vesicles appended to the feet of the Asterias . .148 



98 Polygonal pieces composing the test of the Echinus . . 150 



99 Structure of a detached piece of ditto . . . ' 15() 



100 Spine of the Cidaris, (Carus) . . . * . 150 



101 Shell o^-Unio batava, (Goldfuss) . . . , ' j^g 



102 Adductor muscle of Oyster, (Hunterian Museum) . . I'eo 



103 Shell orPholas Candida, with abductor muscle, (Osier) . 161 



104 Foot of Cardium edule, (Reaumur) . . . .162 



105 Planorbus cornutus (Cuvier) ... * 166 



106 Magnified view of the striae on the surface of Mother' of 



Pearl, (Herschel) •• ... 169 



107 Directions of the fibres in the component strata of shells . 170 



108 Shell of Ac/i«fm«ze6r«, (DeBlainville) . . I'ya 



109 Longitudinal section of ditto, (id.) . . , ' j-^g 



110 Shell ofPterocerus scorpio, at an early stage of growth, (id.) ' 178 



111 Shell of the same when completely formed, (id.) . . 173 



112 Shell of Ci/proia exanthema at an early period of growth, (id.) ' 178 



113 Shell of the same animal, when completed, (id.) . 179 



114 Transverse section of the shell of the CyprcBa exanthema, ' 



(Hunterian Museum) . i-o 



115 Shell of CoMMs . ..'.** jQj 



110 Longitudinal section of the same, (original) . . .181 



117 Transverse section of the same, (Brug°jiere) . * . * 181 



118 Inner surface of the Epiphragma of the Helix pomatia, (De 



^l^'"vil^e) • 183 



