INDEX OF SCIENTIFIC TERMS 223 



Labium — lower 'lip' or lower surface of mouth between the maxillae of 

 an arthropod 



Labrum — upper 'lip' of an arthropod 75, 107 



Lacuna — space among the tissues serving in place of vessels for the cir- 

 culation of the blood 47 



Lamella — one of an aggregate of thin plates which compose gills, lung- 

 books, etc . 



Lamina — blade-like structure. On fingers of false-scorpion 100 



Laterigrade — able to run sideways 



Luciferin — substance oxidised in the presence of luciferase to form oxy- 

 luciferin. The reaction is accompanied by the production of light 26 



Luciferase — enzyme in the presence of which luciferin is oxidised and 

 light produced 26 



Lyriform organ — lyre-shaped sensillae of harvest-spiders 138 



Malleoli — organs of unknown function on the legs of the fourth pair in 

 Solifugae, otherwise known as 'racquet organs' 87 



Mandibles — ^modified anterior limbs of arthropods forming jaws primi- 

 tively adapted for chewing. The chelicerae of Arachnids 



Marsupium — brood pouch of woodlice 1,12 



Maxilla — one of the anterior appendages of insects and other arthropods 

 so modified as to serve the purpose of mastication 



Maxillipede — poison claw or toxocognath of centipedes, literally 'jaw- 

 foot' 40, 50-4 



Mesopeltidium — central portion of carapace in Schizomida 121 



Metapeltidium — posterior portion of carapace in Schizomida 121 



Metachronal wave or rhythm — ^wave of rhythmic movement of similar 

 objects, such as cilia or the legs of a millipede in which each is slightly 

 and equally out of phase with the next 20 



Metamorphosis — ecdysis accompanied by a change in form from larva 

 to nymph, or nymph to adult instar {q.v.) 



Metapodosoma — posterior part of prosoma of mites, bearing third and 

 fourth pairs of legs 1 83 



Metasoma — hind region of opisthosoma of scorpions, etc., forming a tail 

 region 70, 99 



Metatarsus — penultimate segment of an Arachnid's leg 



Miillerian mimicry — imitation of the conspicuous or aposematic ap- 

 pearance of one distasteful animal by another, resulting in a reduction 

 in the losses required to teach would-be predators to avoid this par- 

 ticular appearance or colour pattern and thus benefiting both species 

 equally 194-5 



Myrmecophilous — living in company with ants 



Ocellus — simple type of eye, sometimes occurring in groups, but which, 

 by itself, cannot provide form-vision 40, 44, 47, 138 



