GLOSSARY. 217 



Endoderm. The inner embryonic layer. 



Endoparasite. A parasite inside of the body. 



Endo-phragmal skeleton. Chitinous plates that cover the nerve-chain 



and ventral blood-sinus in the thorax of certain crustaceans. 

 Endoplasm. Inner portion of an Amoeba and other Protozoa. 

 Endopod. The branch of a biramous appendage of an arthropod that is 



nearest the mid-line of the body. 

 Endoskeleton. An internal skeleton. 

 Endostyle. A ciliated groove in the ventral wall of the pharynx of an 



ascidian. 

 Ephyra. An embryonic stage of Discomedusae. 

 Epicardium. A hollow process from the pharynx of some ascidians. See 



Amaroecium. 

 Epipharynx. A projection from the roof of the mouth of some insects. 

 Epiphysis. A plate joined to the base of the alveolus in the mouth-parts 



of an echinoid. 

 Epipod. A membranous projection found on certain crustacean limbs, 



that extends into the gill chamber. 

 Episternum. A lateral piece next to the sternum of arthropods. 

 Epistome. A projection above the mouth. See Pectinatella. 

 Esophagus. The portion of the alimentary canal that leads back from 



the mouth or pharynx. 

 Euglenoid. Similar to Euglena, especially in movements. 

 Exopod. The branch of the biramous appendage of an arthropod that is 



away from the mid-line of the body. 

 Exoskeleton. An outer covering, as a shell. 

 Exumbrella. The convex side of a medusa. 



Eye-spot. A pigment spot generally supposed to be associated with per- 

 ception of light. 



Femur. The third segment from the body of the leg of an insect. 



Fission. A method of asexual reproduction by division. 



Flagellum. An elongated vibratory projection of a cell. 



Flame-cell. The terminal cell of one of the excretory tubes of the Platy- 



helminthes. 

 Foot. A locomotor organ. See Venus. 

 Funiculus. A strand of connective tissue that connects the stomach with 



the body-wall in Polyzoa. 

 Funnel. The tube through which water is expelled from the mantle 



chamber by cephalopods. 



Ganglion. A group of nerve cells. 



Gastric filament. One of the filaments in the stomach of Scyphozoa. 



