GLOSSARY. 513 



Insectivorous. — Feeding' on Insects. 



Invertebrata, or Invertebrate Animals. — Those animals which 

 do not possess a backbone or spinal column. 



Lacuna. — Spaces left among the tissues in some of the lower 

 animals, and serving in place of vessels for the circulation of the 

 fluids of the body. 



Lamellated. — Furnished with lamellae or little plates. 



Larva (pi. Larv^). — The first condition of an insect at its issuing 

 from the egg, when it is usually iu the form of a grub, cater- 

 pillar or maggot. 



Larynx. — The upper part of the windpipe opening into the gullet. 



Laurentian. — A group of greatly altered and very ancient rocks, 

 which is greatly developed along the course of the St. Lawrence, 

 whence the name. It is in these that the earliest known traces 

 of organic bodies have been found. 



Legumtnos^. — An order of plants represented by the common Peas 

 and Beans, having an irregular flower in which one petal stands 

 up like a wing, and the stamens and pistil are inclosed in a 

 sheath formed by two other petals. The fruit is a pod (or 

 legume). 



Lemurid^e. — A group of four-handed animals, distinct from the 

 Monkeys, and approaching the Insectivorous Quadrupeds in some 

 of their characters and habits. Its members have the nostrils 

 curved or twisted, and a claw instead of a nail upon the first 

 finger of the hind hands. 



Lepidoptera. — An order of Insects, characterized by the possession 

 of a spiral proboscis, and of four large more or less scaly wings. 

 It includes the well-known Butterflies and Moths. 



Littoral. — Inhabiting the sea-shore. 



Loess. — A marly deposit of recent (Post-Tertiary) date, which occu- 

 pies a great part of the valley of the Rhine. 



Malacostraca. — The higher division of the Crustacea, including 

 the ordinary Crabs, Lobsters, Shrimps, etc., together with the 

 Wood-lice and Sand-hoppers. 



Mammalia. — The highest class of animals, including the ordinary 

 hairy quadrupeds, the Whales and Man, and characterized by 

 the production of living young which are nourished after birth 

 by milk from the teats {Mammce, Mammary glands) of the 

 mother. A striking difference in embryonic development has 

 led to the division of this class into two great groups; in one of 

 these, when the embryo has attained a certain stage, a vascular 

 connection, called the placenta, is formed between the embryo 

 and the mother; in the other this is wanting, and the young are 

 produced in a very incomplete state. The former, including the 

 greater part of the class, are called Placental mammals; the 

 latter, or Aplacental mammals, include the Marsupials and Mono- 

 tremes {Ornithorhynchus). 



Mammiferous. — Having mammge or teats (see Mammalia). 



Mandibles in Insects. — The first or uppermost pair of jaws, which 



