GLOSSARY. 



279 



QE-sopn'A-GUS (Gr. oisos, a reed ; 

 phagein, to eat). The gullet. 



ON-TOG'E-NY (Gr. on, ontos, being; 

 gene, birth). The development 

 from the egg, of au individual 

 animal. 



O-PER'CU-LUM (Lat. operio, to 

 cover). In fishes one or more 

 "bones covering the gills ; in 

 Gastropod mollusks a horny 

 plate or solid limestone mass 

 closing the orifice of shells. 



O-PIS-THO-CCE'LOTJS (Gr. opistlten, 

 behind ; k&ilos, hollow). Those 

 vertebrates with bodies hollow 

 behind and convex in front. 



O'RAL. Related to the mouth. 



OR NI THO-DEL'PH I-A (Gr. ornis, 

 bird ; delpJius, womb). The 

 sub class of mammals and or 

 der Monotremata. 



OR THOP'TE-RA (Gr. orthos, 

 straight ; pteron, wing). The 

 order of insects with straight 

 narrow fore-wings, as the grass- 

 hoppers. 



OS-TRA'CO-DA (Gr. ostracodes, 

 shelled). A group of shelled 

 Crustacea. 



O'TO-LITHS (Gr. oun, ear ; lit?iox, 

 stone). Small bones suspended 

 in the internal ear of fishes, or 

 concretions in the auditory 

 sacs of invertebrates. 



O-VIP'A ROUS (Lat. ovum, an egg; 

 pario, I bring forth). Applied 

 to animals bringing forth eggs 

 instead of living, active young. 



O-VI-POS'I-TOR (Lat. ovum, an 

 egg; pono, I place). An organ 

 in insects homologous with the 

 sting, by which eggs are de- 

 posited in solid substances. 



O'VI-SAC. A sac or bag -like mem- 



brane attached to the parent, 

 and containing eggs. 

 O VO-VT-YIP'A-ROUS (Lat. ovum, 

 an egg; vims, alive; pario, I 

 bring forth). Applied to such 

 animals as retain their eggs in 

 the body until they are hatched. 



DO GEN'E-SFS. Parthenoge- 

 nous development in larval in- 

 sects. 



PAL'LT-UM (Lat. a cloak). The 

 mantle or body-wall of mol- 

 lusks, which secretes the shell; 

 adj. pallia!. 



PA-PIL'LA. A minute soft projec- 

 tion. 



PA-REN'CIIY MA (Gr. paregchuma, 

 from para, en, cJnw, something 

 poured in besides). Applied 

 to the proper substance of vis- 

 cera, excluding connective tis- 

 sue, blood-vessels, and other 

 accessory parts. 



PAR THE NO GEN'E-SIS (Gr. par- 

 tJtenos, virgin; genesis, genera- 

 tion). Reproduction by direct 

 growth of germs from the egg, 

 without fertilization by male 

 germs or spermatozoa, as in the 

 aphis, gall-insects, fluke-worm, 

 etc. 



PEL/A GIG. Living on the high 

 seas, away from the coast; in 

 mid-ocean. 



PER' -i SOME (Gr. peri, around; 

 soma, body). In Crinoids the 

 oral region of the cup or body. 



PER-EN-NI URAN'CHI-A TA (Lat. 

 perennis, perennial; brnncMa, 

 gill). Those Batrachia which re- 

 tain their gills throughout life. 



PER-IS-SO DAC'TY-LA (Gr. perissos, 

 uneven; daktulos, finger). 



