ILLUSTRATIONS xxiii 



FiGnRE Page 



121. Stages of growth of the lophophoru in Thecidea, Cistella, and 



Megalhyris .... . 279 



122. StaL^us of growth of the lophophore in the Terebratellidaj and 



Tert-bratulidfe .... 280 



123. Metamorphoses of the brachidiura in Dielasma turgidum . . . 281 



124. Early stages of lophophore of Glottidia and adult brachia in 



Lingula and Heviilhyris 282 



125. Metamorphoses of brachidium of Zygospira and adult brachid- 



ium of Rkynchospira . . . ... 284 



126-128. Development of internal apparatus in Homceospira evax . 365 



129. Deltidial development in Splrifer . . .... . 384 



130. Deltidial development in 1, 2, Spiriferina pinguis Deslong- 



champs ; 3, 4, Spiriferina WalcoUi Sowerby ; 5, Spiriferina 



rostrata Schlotheim .... . ... 393 



131. Bdnhites various Co^r?nl; ventral area . .... 402 



132. Genesis of Bilobites 404 



