410 GLOSSARY 



LAMELLATKD. Furnished with lamellae or little plates. 



LARVA (pi. LARVJE). The first condition of an insect at its issuing from the 



egg, when it is usually in the form of a grub, caterpillar, or maggot. 

 LARYNX. The upper part of the windpipe opening into the gullet. 

 LAVRENTIAN. A group of greatly altered and very ancient rocks, -which is 



greatly developed along the course of the St. Laurence, whence the name. 



It is in these that the earliest known traces of organic bodies have been 



found. 

 LEGUMINOS;E. 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 enclosed 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, characterised 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 seashore 

 LOESS. A marly deposit of recent (Post-Tertiary) date, which occupies a 



great part of the valley of the Rhine. 



MALACOSTRACA. The higher division of the Crustacea, including the ordinary 

 Crabs, Lobsters, Shrimps, &c., together with the "Woodlice and Sand- 

 hoppers. 



MAMMALIA. The highest class of animals, including the ordinary hairy 

 quadrupeds, the Whales, and Man, and characterised by the production of 

 living young which are nourished after birth by milk from the teats 

 (Mamma;, 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 Placenta! mammals ; the latter, or Aplacental mammals, 

 include the Marsupials and Monotremes (Ornithorhynchus) 



MAMMIFEROUS. Having mammae or teats (see MAMMALIA). 



MANDIBLES, in Insects. The first or uppermost pair of jaws, which are 

 generally solid, horny, biting organs. In Birds the term is applied to 

 both jaws with their horny coverings. In Quadrupeds the mandible is 

 properly the lower jaw. 



MARSUPIALS. An order of Mammalia in which the young are born in a very 

 incomplete state of development, and carried by the mother, -while sucking', 

 in a ventral pouch (marsupium), such as the Kangaroos, Opossums, &c. 

 (see MAMMALIA). 



MAXILUE, in Insects. The second or lower pair of jaws, which are composed 

 of several joints and furnished with peculiar jointed appendages called 

 palpi, or feelers. 



MELANISM. The opposite of albinism ; an undue development of colouring 

 material in the skin and its appendages. 



METAMORPHIC ROCKS. Sedimentary rocks which have undergone alteration, 

 generally by the action of heat, subsequently to their deposition and 

 consolidation. 



MOLLUBCA. One of the great divisions of the Animal Kingdom, including 

 those animals which ha\e a soft body, usually furnished with a shell, and 



