The webs usually have a large flat sheet, supported by threads above and below, under which the spider lives. Some species have the sheet of web curved upward or downward. Linyphia marginata forms a dome-shaped web four or five inches in diameter.

THE GENUS LINYPHIA

These spiders vary in size like the species of Theridium, from a quarter of an inch to a tenth of an inch long. In appearance they differ greatly from Theridium; the cephalothorax is longer and higher in front, the legs are long and slender, with distinct spines, and the abdomen is sometimes a little flattened on the back as in Steatoda, but oftener high in front and a little pointed toward the spinnerets. The sexes differ little in size, but often in color and markings. The palpal organs and the terminal joints of the palpi of the males are very large and complicated, and in the smaller species form the best means of distinguishing them. There are a great number of minute species of Microneta, Bathyphantes, and other allied genera, but only the larger and more common are here described.

Linyphia marginata.—This is one of the most common web spiders in shady woods all through the summer. It is a sixth of an inch long, with slender legs, the longest of which are usually half an inch. The cephalothorax is two-thirds as wide as long, the middle of it brown and the edges light. The abdomen is flat on top and widest and thickest behind, the colors light yellow and purplish brown [(fig. 319)]. In the middle there is a dark stripe, consisting usually of three parts united by a narrow line, and behind this is another dark spot. At the sides are several dark stripes, the front ones lengthwise and the hinder vertical, all connected with the dark color of the under side. The legs are light yellow without markings, and the hairs and spines fine and not easily seen. In the males all the colors are darker and the abdomen narrower, with only a few light marks at the sides. This spider has no nest, but lives all the time in the middle of its web. It matures in June, and the young brood are common in their small webs in August and September.