LIST OF ILLUSTRATIONS 



FIG. 



106. Nereis dumerilii, natural size 



107. Nereis dumerilii, parapodium 

 10S. Nereis dumerilii, setae . 



109. Nereis dumerilii, anatomy . 



1 10. Nereis dumerilii, transverse section 



111. Section through the eye of Nereis 



112. Brain and connecting nerves of Nereis 



1 13. Serpulae in their tubes . 



114. Trochosphere of Eupomatus 



115. Lumbrieus agricola ... 



116. Lumbrieus, setse .... 



117. Hirudo rnedicinalis .... 



118. Head of Hirudo rnedicinalis, showing the th 



119. Head of Hirudo quinquestriata . 



120. Nephridium of the medicinal leech 



121. Transverse section of Hirudo 



122. Diagram of blood-channels of leech 



123. Astacus fiuviatilis 



124. Appendages of Astacus 



125. Astacus fiuviatilis, dissection from right side 



126. Respiratory organs of Astacus fiuviatilis 



127. Thorax of crayfish, transverse section . 

 12S. Diagram of the circulation in the crayfish 



129. Nervous system of Astacus fiuviatilis . 



130. Reproductive organs of Astacus fiuviatilis 



131. Cancer pagurus . 



132. Pagurus bernhardus 



133. Apus glaciahs 



134. Development of Apus . 



135. Cyclops and Calocalanus 



136. Lepas anatifera . 



137. Peripatus capensis 

 13S. Peripatus capensis. head, etc. 



139. Internal organs of Peripatus 



140. Scolopendra 



141. Periplaneta americana . 



142. Mouth-parts of the cockroach 



143. Pieris rapae, larva, and pupa 



