Different kinds of spiders mature and breed at different times of the year, most of them living only one season. Those that mature late, like _Agalena nævia_ and Argiope, pass the winter as eggs, while those that mature early, like _Epeira sclopetaria_ and _Lycosa nidicola_, pass the winter half grown. Some species, like _Theridium tepidariorum_ (p. 112), breed several times in the year, and old and young are found at all seasons. The spiders are naturally divided into two groups of families: (1) the hunting spiders, which run on the ground or on plants, catching insects wherever they find them, or waiting among leaves and flowers until insects come within their reach; (2) the cobweb spiders, which make webs to catch insects and live all the time in the web or in a nest near it. The hunting spiders include: (1) the Dysderidæ (p. 22), a few species with six eyes only and with four breathing holes at the front end of the abdomen; (2) the Drassidæ (p. 1), or ground spiders, which live among stones and dead leaves or among plants, making tubular nests and flat egg cocoons but no cobwebs; (3) the Thomisidæ (p. 24), the flat and crab-like spiders living on plants or under bark and stones; (4) the Attidæ (p. 41), the jumping spiders, with wide heads and large front eyes, many of them brightly colored and active in their habits; (5) the Lycosidæ (p. 67), the long-legged running spiders, living on the ground and, a few of them, in holes and carrying about their round egg cocoons attached to the spinnerets. The cobweb spiders include: (1) the Agalenidæ (p. 91), making flat webs on grass or in corners of houses, with a tube at one side in which the spider lives; (2) the Therididæ (p. 107), round spiders with flat or irregular webs in corners and on plants; (3) the Linyphiadæ (p. 134), with flat webs, small spiders of a great number of species living near the ground and in shady places; (4) the Epeiridæ (p. 154), the round web spiders; (5) the Cribellata, having a calamistrum (see p. 205) on the hind legs and making rough webs that gather dust. Cobwebs are of four principal kinds: 1. The flat webs, closely woven of long threads crossed by finer ones in all directions and connected with a tubular nest where the spider hides, and from which it runs out on the upper side of the web after insects that may fall upon it. These are made by Agalena and Tegenaria (pp. 91 to 104). 2. The net-like webs, made of smooth threads in large meshes, sometimes in a flat or curved sheet held out by threads in all directions. The spider lives on the under side, back downward. These are made by Therididæ and Linyphiadæ (pp. 107, 134). 3. The round webs, made of threads radiating from a common center and crossed by circular loops and spirals, part of which are adhesive. 4. The webs of the Ciniflonidæ, composed in part of loose bands of silk (p. 205).