. Text-book of embryology. Embryology. 216 INVEKTEBEATA CHAP. crabs, just as clearly as the Mysis larva represents a Schizopod stage in the ancestry of Macrura. The Megalopa is transformed into the adult by one or two moults. The life-history of the Anomura closely resembles that of the Brachyura; in their case also the Mysis stage is omitted, but the third appendage of the thorax, the third maxillipede, becomes func- tional before the critical A , . , 2 moult which ends the free- z^,***'*'^ swimming life. The post- -*' larval stage of the Paguridae or hermit crabs, which corre- sponds to the  - Stock Image