370 GLOSSAliY. 



INVERTEDRATA (Lat. in, without ; vertebra, a bone of tlie 'back). Animals 



without a spinal column or backbone. 

 IsOPODA (Gr. isos, equal ; podes, feet). An order of Crustacea in which the 



feet are equal and like one another. 



Labium (Lat. for lip). Restricted to the lower lip of Articulate animals. 



Labrum (Lat. for lip). Restricted to the upper lip in Articulate animals. 



Labyrinthodontia (Gr. laburinlhos, a labyrinth ; odous, a tooth). An extinct 

 order of Amphibia. 



Lacertilla (Lat. lacerta, a lizard). An order of Rcptilia, comprising the 

 Lizards and Slow-worms. 



LiEMODiPODA (Gr. laimos, throat ; dis, twice ; podes, feet). An order of Crus- 

 tacea with two legs under the throat. 



LAjrELLIBKAKCHlATA (Lat. lamella, a plate ; Gr. brac/chia, gills). The class of 

 Mollusca comprising the ordinary Bivalves with leaf-like gills. 



Larva (Lat. a mask). The insect in its tirst stage after its emergence from 

 the egg, when it is usually very different from the adult. 



Lepjdoptera (Gr. lepis, a scale ; pteron, a wing). The order of Insects, com- 

 prising the Butterflies and Moths, characterised by having four wings usually 

 covered by minute scales. 



Lingual (Lat. lingita, tongue). Connected with the tongue. 



LUCERNARIDA (Lat. luccrria, a lamp). An order of the Jlydrozoa. 



Lu.mbar (Lat. lumbus, a loin). Connected with the loins. 



MaCRUKA (Gr. makros, long ; oura, tail). A tribe of Decapod Crustaceans 

 with long tails (e.o., the Lobster, Shrimp, &c. ) 



M.\DRt:PORiFOR.M. Perforated by small holes, like a coral (or madrepore), 

 applied to the spongy tubercle by which the water-vascular system of 

 Echiuoderms mostly communicates with the exterior. 



Malacodermata (Gr. malakos, soft; derma, skin). Applied to a group of 

 tlie Actmozoa, comprising the soft-skinned Sea-anemones. 



Mallophaga (Gr. inallos, a fleece ; phago, I eat). An order of Insects, com- 

 prising the Bird-lice. 



Mammalia (Lat. mamma, the breast). The class of Vertebrate animals which 

 suckle their young. 



Mandible (Lat. mandibulum, a jaw.) The mandibles are the first pair of 

 jaws in Insects and Crustaceans. In Spiders tliey are the nioditied antennse. 

 In Ccphalopods they constitute the horny beak. The lower jaw of \'erte- 

 brates is the mandible. 



Mantle. The external integument of most of the Mollusca, which is largely 

 developed, and forms a cloak lor the intei'nal organs. Technically called the 

 " pallium." 



Manubrium (Lat. a handle). The central polyjjitc which is suspended from 

 the roof of the swiinining-l)ell of a Medusa or niedusiforin gonophore amongst 

 the Jlydrozoa. 



MAi!SIPOBnANCiiII(Gr. marsipos, a pouch; bragcliia, gills). An order of Fishes, 

 comprising the Uag-hshes and Lampreys, with pouch-like gills. 



Marsupialia (Lat. marsupium, a pouch). An order of Mammals, in which 

 the females are usually turn shed with an abdominal pouch in which the 

 young are carried. 



Masticatory (Lat. mastico, 1 chew). Adapted for chewing. 



Medusa. A group of H'ldm-.na., commonly known as Jelly-fishes, so called 

 because of the resemblance of their tentacles to the snaky hair of the Medusa. 



Medusifobm. Resembling a Medusa in shape. 



Medusoid. Like a Medusa. Used as a noun to designate the medusiform 

 generative buds (gonophores) of the Hydrozoa. 



Membrana nictitans (Lat. nicto, I wink). The third eyelid present in Birds, &c. 



Meiiostomata (Gr. me)'on, thigh ; stoma, mouth). An order of Crustacea. 



Me.senteries (Gr. mesos, intermediate; entermi, intestine). The membrane 

 by which the intestine is attached to the walls of the abdomen. In a re- 

 stricted sense, the vertical plates which divide the somatic cavity of a Sea- 

 anemone into chambers. 



