Asagena americana.—This resembles Steatoda, but the abdomen is longer and flatter, and the whole appearance more like some of the Drassidæ. Like Steatoda, it is usually found with its web under stones. It is about a sixth of an inch long. The cephalothorax is dark reddish brown, slightly rough in the females and with sharp points along the sides in the males. The legs are yellow brown and in the males have two rows of small teeth under each femur. They are stout, as in Steatoda marmorata, and differ little in length. The abdomen is oval and dark brown in color, with two white spots across the middle [(fig. 287)]. The front of the head is rounded and a third as wide as the thorax. The eyes are close together and all about the same size. The males have the cephalothorax larger and rougher, but in size and color resemble the females.

Latrodectus mactans.—This is the largest spider of the family. It is sometimes half an inch long, with the abdomen round and the whole body black, except a bright red spot underneath and one or more red spots over the spinnerets and along the middle of the back (figs. [289, 290]). The spots turn yellow or white in alcohol. The cephalothorax is about as wide as long, and the grooves between the head and thorax are deep. The lateral eyes are farther apart than usual in this family. The legs of the male are much larger than those of the female, and each joint is orange brown in the middle and black at the ends. The abdomen of the male has a row of red and white spots in the middle line, as some females do, and across the front end, and along the sides four pairs of stripes, red in the middle and white at the edges [(fig. 291)]. The young of both sexes are colored somewhat like the male and, when very small, have very little black on them. The males vary much in size, some being only a quarter as large as the female. This spider makes its nest among loose stones, on plants, or in houses. Around its hiding place it spins a large funnel-shaped tent that widens into a flat or curved sheet of web, closer in texture toward the tube and more open toward the edges, spreading two or three feet over plants and stones. It is found all over the United States, as far north as Massachusetts and New Hampshire and south through Florida, the West Indies, and South America, as far as Chile. It is everywhere feared as poisonous and dangerous, probably on account of its large size and conspicuous colors, as there is no good reason for considering it more poisonous than other spiders.

Argyrodes trigonum.—A little yellow triangular spider, with a high, pointed abdomen [(fig. 292)]. Large females measure an eighth of an inch from the head to the spinnerets and nearly as much from the spinnerets to the tip of the abdomen. Seen from above, the end of the abdomen is a little flattened and notched in the middle [(fig. 293)]. In the female the part of the head around the eyes is slightly raised and the lower part of the front of the head carried forward a little beyond it [(fig. 294)]. In the males there are two horns on the head, one between the eyes and one below them [(fig. 295)]. The color is light yellow, sometimes with a metallic luster, as though gilded. On the back of the cephalothorax are three light brown stripes, and sometimes there are dark spots at the sides of the abdomen and over the spinnerets. The legs are slender, without markings, the front pair longer than the others. The point of the abdomen is movable and is sometimes curved downward when the spider is disturbed in the web, as shown by the dotted line in [fig. 292]. They make webs like those of Theridium, between branches of shrubs [(fig. 296)] and also among the upper threads of the webs of larger spiders. They have been found in the webs of Agalena, Theridium, and Linyphia, in the looser parts, out of reach of the maker of the web. Hanging in the web, they look like straws or the scales of pine buds that have fallen into it. The cocoons of eggs hang in the web and have a peculiar shape [(fig. 296)], the upper part conical and the lower part contracted into a narrow neck. The species is common in New England and is found all over the country as far south as Florida.