GLOSSARY. 3S: 



Oo^OP'o-DA (Gr. odo. eigbt ; _pow.?, foot). The tribe- o'( Cuttle-fishes witb 

 eight arms attached to the head. 



0-don-to-ce'ti (Gr. odous^ tooth ; iMos, Tvhale). The "toothed" "Whales, in 

 contradistinction to the " whalebone " Whales. 



0-don'toid (Gr. odous ; eidos^ fomi). The " odontoid process " is the centrum 

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

 and is usually anchylosed with the second cervical vertebra {axis}^ and it 

 forms the pivot upon which the head rotates. 



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

 or masticatory apparatus of Gasteropoda, Pteropoda, and Cephalopoda. 



CE-soph'a-gu3. The gullet or tube leading from the mouth to the stomach. 



Ul-i-go-ch^e'ta (Gr. oligoi., i<i^ \ chaiie, hair). An order of ^/i/tf^^^ci^a, com- 

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



0-ua'sum (Lat. for bullock's tripe). The third stomach of Euminants, com- 

 monly called the psalteriwm; or many-plies. 



Om-wiv O-Rous (Lat. omnia, e verv thing ; mvo, 1 devour). Feeding indis- 

 criminately upon all sorts of food. 



0-pek-cu-la'ta (Lat. o^yerculum, a lid). A division of pulmonate Ga8t(rop' 

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



O-per'cu-lujVT. a horny or shelly i:ilate developed in certain Mollusca. iipon 

 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 Acorn-shell ; also the chain of flat bones which cover the gills in 

 many fishes. 



0-phid'i-a (Gr. opiJddicn, a little snake). The order of Keptilcs comprising 

 the Snakes. 



Opii-i-do-ba-tra'chi-a fGr. opMs, a snake; hatracTios, a frog). Sometimes ai> 

 plied to the order of Snake-like Amphibians comprising the Ccecilia:. 



Oph-i-o-mok'pha (Gr. oijlds ; nwrpjlie, shape). The order of Amphibia com- 

 prising the 0(Bcili(B. 



Oph-i-u-roid'e-a (Gr. ophis^ a snake; owrcr, tail ■ eidos, fonn). An order of 

 A'e/dnod&rmata comprising the Brittle-stars and Sand-stars. 



0-pis-tho-bkanch-i-a'ta (Gr. opisthen, behind; hragdtia., g\\\i\). A division 

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

 body. 



0-pis-THO-ciE'Lous (Gr. opisthen, behind; loilos, hollow). Apitlicd to verte- 

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



O'ltAL (Lat. OS. mouth). Connected with the mouth. 



Ur-ni-tho-del phi-a ( Gr. or/ds, a bird ; delphus, womb). The primary divis- 

 ion of Mammals comprising the Mon-otremata. 



Or-thop'te-ra (Gr. ortkos^ straight ; pterori, wing). An order of Insects. 



Os'cu-LA (Lat. diminutive of os^ mouth). 1. The large apertures by which a 

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

 tne Toiniada (Tape-worms and Cystic Worms) are provided. 



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

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

 in the integument of the Star-fishes. 



Os-TRA-co'uA (Gr. ostraJcon, a shell ■ and eidos, form). An order of small 

 Crustaceans which are enclosed in bivalve shells. 



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

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



0-va'ri-an Ves-i-cles or Cap'sules. The generative buds of the Sertularida. 

 (VvA-RY (0-va'ri-um). The organ by which ova are produced. 

 0-vip'a-rous (Lat. ':>?''-/m, an egg; and /jc/rw, I biing forth). Applied to ani- 

 mals which bring forth Qggi-; in contradistinction to thosu which bring forth 

 theii' young alive. 

 0-vi-pos'i-TOR (Lat. ovum ; ViXidi pono, I place). The organ possessed by 

 some insects, by means of whie-h the eggs are placed in a position suitable 

 for their development. 

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

 carry their eggs after they are extruded from the body. 



