GLOSSARY OF TECHNICAL TERMS. 605 



Oosperm. Fertilized egg. 



Oostcgopod. Brood-foot, or modified appendage to hold ova, as in some 



phyllopods. 

 Ophthalmic. Relating to the eye. 

 Ophthahnopod. Eye-stalk. 

 Oral. With reference to the mouth. 

 Orbiculate. Round or circular. 

 Ostia. Entrance or opening. 

 Ovisac. Egg-pouch. 



Palm. Inner part of the hand. 



Palp. Appendage (feeler) ; usually to the mouth-organs. 



Papillifonn. Formed like a nipple. 



Paragnatha. Pair of small processes between maxillae and mandibles, as in 

 some phyllopods. 



Parasitic. An animal living or deriving its existence at the expense of 

 another. 



Paries. Free middle part of shell as distinguished from the lateral wings in 

 barnacles ; plural parietes. 



Parthenogenetic. Said of certain forms in which only females occur, repro- 

 duction taking place without the aid of the male. 



Pauciarticulate. With few joints. 



Pectinate. Comb-like. 



Pedicel. Foot-stalk. 



Pedigerous. Bearing feet. 



Pedipalp. Foot appendage or feeler. 



Peduncle. Basal joint or joints of antenna; stalk of certain barnacles. 



Pedunculate. Stalked. 



Pelagic. Oceanic. 



Pencil. Brush. 



Pendant. Streamer. 



Penniform. Shaped like a feather. 



Pentagonal. Like a figure with five angles. 



Pcrccoi. The thorax as distinguished from the head and abdomen Some- 

 times written pereion. 



Perceopods. Third to seventh pairs of legs or appendages of mesosome, in 

 amphipods and macrurans ; also called first to fifth pairs of perjeopods. 

 Sometimes called pereiopods. 



Pericardial. Relating to the membrane enclosing the heart. 



Petasma. Or andricum, the male organ on first pair of abdominal appendages 

 of some prawns. 



Phyllobranchice. Leaf-like gills. 



Phylum. A primary division, as a sub-kingdom of the animal kingdom. 



Piliferous. Bearing or tipped with hairs. 



Pinnate. Shaped like a feather. 



Plastic. Capable of being moulded. 



Plastron. The lower shell, as opposed to the carapace. 



Pleocleis. Tubercle or wart-like protuberance on first somite of pleon, pre- 

 venting elevation of carapace behind. 



