ILLUSTEATIONS xxi 



PAGE 



126. The formation of the appendages in the embryo of Peripatus capensis . 175 



127. Two sections through the developing egg of ^stocijs . . .179 



128. Sagittal section through the blastiila of Astacus fiuviatiUs in order to 



show the primary yolk pyramids ...... 180 



129. Ventral view of an embryo of Astacus fluviottilis, the gastrula stage, in 



order to show the ventral plate ...... 181 



130. Sagittal section through a portion of the embryo of Astacas fluviatiUs in 



order to show the invagination of the endodermic rudiment . . 182 



131. Two sagittal sections through developing eggs of Astacus fluviatiUs in 



order to show the development of the endoderm .... 182 



132. The " Nauplius " stage in the development of Astacus fluviatiUs, viewed 



from the ventral side . . . . . . .184. 



133. Three transverse sections through the developing nerve cord of Astacus 



fluviatiUs ......... 185 



134. Two views of developing eggs of Astacus fluviatiUs from the ventral surface 186 



135. Transverse section through the region of the heart in an embryo of 



Astacus fluviatiUs in about the same stage as that represented in Fig. 



134 B ■. . .187 



136. Longitudinal section through advanced embryo of Astacus fluviatiUs 



parallel to the sagittal direction but to one side of the middle line . 187 



137. Advanced embryo of Astacus fluviatiUs, viewed from the ventral side. The 



abdomen and hinder part of the thorax are cut off and spread out 

 separately ......... 188 



138. Two ommatidia from the eye of a newly-hatohed Astacus fluviatiUs in 



longitudinal section ..... 



139. Two sagittal sections through advanced embryos of Astacus 



140. Portions of two sagittal sections through developing eggs of Hmnarus 



americanus ....... 



141. Sections through the developing egg of Mysis chamaeleo 



142. Stages in the development of the egg of Polyphemus pediculus 



143. Four sagittal sections through the developing eggs of Lepas anatifera in 



different stages of development ..... 



144. The Naupliiis larva of Cyclops canthocarnoidcs from the ventral surface 



145. Three stages in the further development of the larva of Cyclops 



146. Two types of Nauplius larva 



147. The " Cypris " larva or Pupa of Lapas fascicularis, seen from the side 



148. The fixation of the Cypris larva of iepas/ascicMtoris 



149. The Nauplius larva of Cypris ovum ..... 



150. The Protozoaea larva of Nyctiphanes australis 



151. Dorsal and ventral views of the " Copepodid " larva of Adheres arnbloplitis 205 



152. Dorsal and lateral views of the just-fixed female of Adheres arnbloplitis 

 153.- Lateral view of female Adheres arnbloplitis after the adult characteristics 



have been attained . . . . . 



154. Enlarged view of gnathites and lips of female Adheres 



from the side ..... 



155. " Calyptopis " Zoaea of Nyctiphanes australis, lateral view 



156. Zoaea larva of Penaeus, ventral view 

 157.- Zoaea larva of Crangon vulgaris, lateral view 



158. Zoaea larva of Poreellana longicornia after the first moult 



159. Zoaea larva of the Crab Xantho 



160. " Mysis " larva of Somarvs americanus, lateral view 



161. "Fhjllosoma," letrya. of Palinurus vulgaris, ventral view 



162. "Mysis" la,rva,ol Crangon allmanni, Isiteralviewf . 



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 190 



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206 



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