$Tetragnatha extensa.$--Female a quarter to three-eighths of an inch long, with the first leg three-quarters of an inch. The abdomen is shorter than in _grallator_, about twice as long as the cephalothorax, and not as much widened in front (fig. 462). The mandibles are two-thirds as long as the cephalothorax and not much inclined forward. The lateral eyes are near together. The colors are often dark, dull yellow brown or gray, with three lines on the cephalothorax and a middle dark stripe on the abdomen, with a light silvery stripe on each side. The male is smaller and more slender, with the legs longer. The male palpi are one-half longer than the cephalothorax, the femur forming nearly half its length (fig. 466). [Illustration: FIG. 460. The same web shown in Fig. 459, treated so as to show the inner spiral and the hole in the middle of the web.] $Tetragnatha laboriosa.$--A little smaller than _extensa_, with shorter legs and mandibles, the latter short enough in the female to be almost vertical (fig. 463). The abdomen is proportionally longer than in _extensa_, usually in the females three times as long as the cephalothorax. The first legs are about seven times as long as the cephalothorax. The upper row of eyes is a little curved, so that the lateral pairs of eyes are as far apart as the middle ones (fig. 467). The general color is light yellow. The abdomen is silvery white, with some indistinct gray markings along the middle, and dark stripes on the under side. In the males the mandibles (fig. 467) are short compared with the other species, and are about two-thirds as long as the cephalothorax, and the tibia is very little longer than the patella. [Illustration: FIGS. 461, 462, 463, 464. Backs of females of four species of Tetragnatha.--461, grallator. 462, extensa. 463, laboriosa. 464, straminea.] [Illustration: FIGS. 465, 466. Cephalothorax, mandible, and palpus of males.--465, Tetragnatha grallator. 466, Tetragnatha extensa.] [Illustration: FIGS. 467, 468. Cephalothorax, mandibles, and palpus of male.--467, Tetragnatha laboriosa. 468, Tetragnatha straminea.] $Tetragnatha straminea.$--A quarter to three-eighths of an inch long, about the same size as _laboriosa_, and the same color. The legs, palpi, and mandibles are all a little longer than in _laboriosa_, and the lateral eyes are farther apart than the middle pairs (fig. 464). In the males the abdomen is shorter and smaller, and the legs longer. The male palpi (fig. 468) are one and a half times the length of the cephalothorax. In females the abdomen is usually three times as long as the cephalothorax and more slender than in _laboriosa_. THE CINIFLONIDÆ, OR CRIBELLATA [Illustration: FIGS. 469, 470.--469, cribellum. 470, calamistrum of Amaurobius sylvestris.]