LIST OF ENGRAVINGS. XXV 



Fig. Page 



107 Directions of the fibres in the component strata of 



shells 234 



108 Shell of Achatina zebra, (De Blainville) 242 



1 09 Longitudinal section of ditto, (id.) 242 



110 Shell of Pterocerus scorpio, at an early stage of growth, 



(id.) ". 246 



111 Shell of the same when completely formed, (id.) 246 



1 1 2 Shell of Cyprcea exanthema at an early period of 



growth, (id.) 246 



113 Shell of the same animal, when completed, (id.) .... 246 



114 Transverse section of the shell of the Cyprcea exan- 



thema, (Huterian Museum) 248 



115 Shell of Conus 248 



1 16 Longitudinal section of the same, (original) 248 



1 1 7 Transverse section of the same, (Bruguiere) 248 



118 Inner surface of the Epiphragma of the Helix pomatia, 



(De Blainville) 253 



1 19 Outer surface of the same, (id.) 253 



120 Clio borealis, (Cuvier) 258 



121 Sepia loligo, (De Blainville) 259 



122 Suckers of the same (id.) 259 



123 Suckers of the Octopus, (original) 260 



1 24 Shell of Spirula australis, (De Blainville) 265 



125 Longitudinal section of the same (id.) 265 



126 Shell of Nautilus pompilius (id.) 265 



127 Longitudinal section of the same (id.) 265 



128 Pontobdella muricata, (Bruguiere) 27 1 



129 Nereis, (id.) 271 



130 Erpobdella vulgaris (Lam.) Hirudo hyalina 271 



131 Diagram illustrating the rings and muscles of Annelida, 



(original) 271 



1 32 Gordius aquaticus 276 



1 33 Serpula opercularia 276 



134 Terebella conchilcga, (De Blainville) 276 



135 Arenicola piscatorum, or Lumbricus marinus 276 



136 Aranea diadema, (Rresel) 283 



1 37 Divisions of the limb of a Crustaceous animal 287 



138 Mandible and palpus of My sis Fabricii, (Bruguiere) 287 



