382 GLOSSARY. 



NoTAL, (Gr. notos, the back.) Belonging to the back. 



Nucleated. Having a nucleus or central particle ; applied to the elementary 

 cells of animal tissues, the most important properties of whicli reside in the nu- 

 cleus. 



NuDiBRACHiATE. (L,at. nudits, naked ; tracAm, arms. ) The Polypes, whose arms 

 are not clotlied with vibratile cilia. 



NuDiBRANCHiATE. (Lat. iiudus, naked; bragchia, gills.) An order of Gasteropods 

 in which the gills are exposed. 



OcTOPODA. (Gr. octo, eight ; pous, a foot.) Animals with eight feet. The name 

 of the tribe of Cephalopods with eight prehensile organs attached to the liead. 



CEsorHAGUs. The gullet or tube leading from the mouth to the stomach. 



Olfactory. (Lat. olfactus, the sense of smelling ) Relating to that sense. 



Onychoteuthis. ( Gr. onnx, a hook ; teuthis, a calamary.) The genus of Cala- 

 maries armed with hooks or claws. 



Oolite. (Gr. oon, egg; lif/ws, stone.) An extensive group of secondary lime- 

 stones composed of rounded particles, like the roe or eggs of a fish. 



Operculum. (From the Latin for lid.) Applied to the horny or shelly plate 

 which closes certain univalve shells ; also to the covering of the gills in fish, and 

 to the lids of certain eggs. 



Oral. (Lat. os, the mouth.) Belonging to the mouth or to speech. 



Orthocera and Orthoceratite. (Gr. or^Aos, straight ; ^eras, horn.) The extinct 

 Cephalopods whicli inhabited long conical chambered shells like a straight horn. 



Orthoptera. ( Gr. or</ios, straight ; j}tero7i, a wing.) The order of insects, with 

 elytra and longitudinally folded wings. 



Osseous. ( Lat. os, a bone. ) Bony. 



Otolithes. ( G r. o?<s, an ear ; lithos, a stone.) The stony or chalky bodies belong- 

 ing to the internal ear. 



Ovarium. (Lat. ovum, an egg.) The organ in which the eggs or their elementary 

 and essential parts are formed. 



Ovigerous. (Lat. ovum, an egg ; gero, I bear.) Parts containing or supporting 

 eggs. 



Oviparous. (JLat.ovum ; pario, I bring forth. ) The animals which bring forth eggs. 



Ovipositor. {\^at. ovum ; pono, I place.) The organ in insects, which is often 

 large and complicated, for the transmission of the eggs, during exclusion, to 

 their appropriate place. 



OvoviviPAROus. (Lat. ovum, egg; vivus, alive; pario, I produce.) The animals 

 which produce living young, hatched in the egg within the body of the parent, 

 without any connection with the womb. 



Palaeontology. (Gr. pa/a!os, ancient ; o«<a, beings ; Zo^os, discourse. ) The his- 

 tory of ancient extinct organised beings. 



Pallial. (^hat. pallium, a cloak.) Relating to the mantle or cloak of the Mol- 

 lusca. 



Palliobranchiata. (Lat. pallium; branchia, gills.) The class of acephalous 

 Mollusca in which the gills are developed from the mantle. 



Palpi. (Lat. palpo, I touch.) The organs of touch developed from the labium 

 and maxillas of insects. 



Papilla. (Lat. for nipple.) Minute soft prominences, generally adapted for 

 delicate sensation. 



Papyraceous. (Gr. papuros, paper.) Of the consistency of paper. 



Parenchyma. The soft tissue of organs ; generally applied to that of glands. 



Parietes. (Lat. paries, a wall.) The walls of the diflf'erent cavities of an animal 

 body. 



Pectinated. (Lat. pecten, a comb.) Toothed like a comb. 



Pectinibranchiata. (Lat. joec/ew, a comb ; branchia, gills.) The order of Gas- 

 teropods in which the gills are shaped like a comb. 



Pediform. (Lat. pes, a foot.) Shaped like a foot. 



PEnuNCLE. From the Latin pedunculus, a stalk. 



Pedunculated. Suspended or supported by a stalk. 



Pelagic. (Gr. pelages, sea.) Belonging to the deep sea. 



