398 GLOSSAI^Y. 



Mouth. — Formed of six pieces, an upper lij) {lahruvi), lower lip {labium), 



with two pairs of jaws opposed horizontal!}^ between them, of which 



the upper pair (mandibles) are often strong, and serve for biting 



with ; the lower pair {maxillce, or feeler-jaws) are usually smaller, 



and weaker, and are furnished with feelers or palpi, as is also the 



labium. In butterflies, Aphides, &c., that have sucker-mouths, some 



of the above-mentioned portions are variously altered in shape. — See 



Proboscis. 

 Ocelli. — Minute single eyes, usually three in number, fixed on the crown 



of the head, commonly known as simple eyes. 

 Oviparous. — Producing eggs. 



Ovipositor. — Instrument whereby the female insect lays her eggs. 

 Ovum. — Egg. 



Palpi. — Feelers, placed on the lower jaws and lower Up. 

 Poisers (see Halteres). — Appendages in the place of the hinder wings 



of the Diptera. 

 Proboscis. — In butterflies, altered lower jaws forming the spiral trunk ; 



in two-winged flies, the altered lower lip enclosing the piercers. 

 Pro-legs. — Sucker-feet, whereby caterpillars and other larvaj hold firmly 



to the substance they are placed on. 

 Pulvilli. — Cushions beneath the feet of flies and some other insects. 

 Pupa. — Second stage of insect-life, in which it is inactive, as with 



the chrysalis of butterflies, in some Orders ; and active and much 



resembling the parent, excepting in the organs of flight not being 



developed, in other Orders, as with grasshoppers. 

 nostrum. — Sometimes called snout, when applied to the prolonged front 



of the head of some kinds of beetles ; also used as well as proboscis 



for the altered labium of Aphides. 

 Scutellum. — A name sometimes applied to a portion of each segment 



of the tliorax, but especially to the triangular shield-shaped plate 



between the base of the wing-cases in beetles and bugs. 

 Segments. — Rings of which an insect is composed — considered to be 



thirteen, including the head. 

 Spiracles. — Breathing-pores, for the most part placed along sides of 



insects, or at the end of the tail, by means of which the air is di'awu 



into or expelled from the trachece, or breathing-tubes. 

 Stigma. — A small thickened spot on the front edge of the fore wing of 



various kinds of insects. 

 Sucker-feet. — Pro-legs ; fleshy appendages whereby larvae hold firmly to 



the twigs, &c., whereon they are placed. 

 Tarsi. — Feet, the fourth chief division of the leg, being that on which 



the insect rests, and composed of a variable number of joints, up 



to five. 

 Telum. — Last segment of the abdomen. 

 Thorax. — The tliree segments next to the head, known respectively as 



the pro-, meso-, and meta-thorax, of which in perfect insects the 



foremost, or pro-thorax, bears a pair of legs, the other two each a 



pair of legs and wings. 

 Tibia. — Shank; third chief division of the leg between the thigh {femur) 



and foot (tarsus). 

 Trachece. — Organs of respiration communicating with the air by 



breathing-pores {spiracles) in the sides of the insect, and conveying 



it by means of smaller tubes throughout the body. 

 Ungues. — Claws or curved hooks at the extremity of the foot. 

 Viviparous. — Producing living young. 



