GLOSSARY. S41 



Oo-Top'o-DA (Gr. octo, eight : pims, foot), 

 eight arms attached to the head. 



The tribe of Cuttle-fishes with 



0-don-to-oe'ti (Gr. odous, tooth ; hetos, whale). The "toothed" Whales, in 

 contradistinotion to the " whalebone " Whales. 



O-don'toid (Gr. odous ; eidos, form). The " odontoid process " is the centrum 

 or body of the first cervical vertebra (atlas). It is detached from the atlas, 

 and is usually anohylosed with the second cervical vertebra (axis), aiid it 

 forms the pivot upon which the head rotates. 



0-don'to-phoee (Gr. odous, tooth ; phero, I carry). The so-called " tongue " 

 or masticatory apparatus of GaMeropoda, Pteropoda, and Cephalopoda. 



CE-soph'a-ods. The gullet or tube leading from the mouth to the stomach. 



0L-i-G0-0Hi:'TA (Gr. oUgoi, few ; ehaUe, hair). An order of Armelida, com- 

 prising the Earth-worms, in which there are few bristles. 



O-MA'smt (Lat. for bullock's tripe). The third stomach of Euminants, com- 

 monly called the psalterium, or many-plies. 



Om-niv o-ROtJs (Lat. omnia, everything; voro, I devour). Feeding indis- 

 criminately upon aU sorts of food. 



0-pee-oc-la'ta (Lat. operculum, a lid). A division of pulmonate Gasterop- 

 oda, in which the shell is closed by an operculum. 



0-PEE'on-LrM. A homy or shelly plate developed in certain Molhisca upon 

 the hinder part of the foot, and serving to close the aperture of the shell 

 when the animal is retracted within it ; also the lid of the shell of a Bala- 

 nus or Aoom-shell ; also the chain of fiat bones which cover the gUls in 

 many fishes. 



O-phid'i-a (Gr. ophidion, a little snake). The order of Keptiles comprising 

 the Snakes. 



Oph-i-do-ba-tea'chi-a (Gr. opTiis, a snake : batraehos, a frog). Sometimes ap- 

 plied to the order of Snake-like Amphibians comprising the Gmcilim. 



Oph-i-o-moe'pha (Gr. opTiis; morp/is^ shape). The order of Amphibia com- 

 prising the CcBcilice. 



Oph-i-u-eoid'e-a (Gr. ophis, a snake ; ourra, tail : eidos, form). An order of 

 EcMnodermMta compnsing the Brittle-stars and Sand-stars. 



0-pis^ho-beanoh-i-a'ta {Qr. opisthen, behind: Sro^c&'a, gills). A division 

 of Gasteropoda in which the gills are placed on the posterior part of the 

 body. 



0-Pis-THO-ccE'Lous (Gr. opisfhen, behind; loilos, hollow). Applied to verte- 

 brae, the bodies of which are hollow or concave behind. 



O'eal (Lat. OS, mouth). Connected with the mouth. 



Oe-ni-tho-del phi-a (Gr. ortds, a bird ; delphus, womb). The primary divis- 

 ion of Mammals comprising the Monotremata, 



Oe-thop'te-ea (Gr. oHhos, straight ; pteron, wing). An order of Insects. 



Os'ou-LA (LaX. diminutive of os, mouth). 1. The large apertures by which a 

 sponge IS perforated (" exhalant apertures"). 2. The suckers with which 

 the Tcmiada (Tape-worms and Cystic Worms) are provided. 



Os-sio'u-LA (Lat. diminutive of os, bone). Literally, small bones. Often used 

 to designate any hard structures of small size, such, as the calcareous plates 

 in the integument of the Star-fishes. 



Os-tea-co'da (Gr. ostralcon, a shell ; and eidos, form). An order of small 

 Crustaceans which are enclosed in bivalve shells. 



Ot'o-liths (Gr. ous, ear ; and Uthos, stone). The calcareous bodies connected 

 with the sense of hearing, even in its most rudimentary form. 



O-va'ri-an Ves-i-oles or OAp'srLES. The generative buds of the Sertularida. 



( I'vA-ET (O-va'ei-um). The organ by which ova are produced. 



0-vip'a-eou8 (Lat. ovum, an egg ; and pario, I bring forth). Applied to ani- 

 mals which bring forth eggs, in contradistinction to those which bring forth 

 their young alive. 



O-vi-pos'mtob (Lat. ovum; smdpono, I place). The organ possessed by 

 some insects, by means of which the eggs are placed in a position suitable 

 for their development. 



O'vi-SAO. The external bag or sac in which certain of the Invertebrates 

 carry their eggs after they are extruded from the body. 



