Tomocerus. Abdominal segments unequal, with simple hairs and scales. Antennae very long, four-jointed, the two terminal segments ringed. Eyes seven in number on each side. (The European T. plumbea, Podura plumbea of authors, is our species, and is common. Fig. 160, greatly enlarged, copied from Templeton; Fig. 159, side view, see also Fig. 161, where the mouth-parts are greatly enlarged, the lettering being the same, _md_, mandibles; _mx_, maxillae; _mp_, maxillary palpus; _lb_, labium; _lp_, labial palpus; _lc_, lacinia; _g_, portion ending in three teeth; _l_, lobe of labium; _sp_, ventral sucking disk; the dotted line's passing through the body represent the course of the intestine; _b_, end of tibia, showing the tarsus, with the claw, and two accessory spines; _a_, third joint of the spring. Fig. 162, lacinia of maxilla greatly enlarged. Fig. 169, different forms of scales, showing the great variation in size and form, the narrow ones running into a linear form, becoming hairs. The markings are also seen to vary, showing, their unreliable character as test objects, unless a single scale is kept for use.) [Illustration: 169. Scales of Tomocerus.] [Illustration: 170. Lepidocyrtus.] [Illustration: 171. Scale of Lepidocyrtus.] Lepidocyrtus. Abdominal segment unequal, with simple hairs and scales. Antennae long, four-jointed. Eyes eight in number on each side. (Fig. 170, L. albinos, an European species, from Hardwicke's "Science Gossip." Fig. 171, a scale. Two species live in New England.) Podura. Abdominal segments subequal. Hairs simple, no scales. Antennae four-jointed, shorter than the head. Eyes eight in number on each side. Saltatory appendage of moderate length. [Illustration: 172. Achorutes.] Achorutes. Abdominal segments subequal. Antennae short, four-jointed. Eyes eight in number on each side. Saltatory appendage quite short. Figure 172 represents a species of this genus very abundant under the bark of trees, etc., in New England. It is of a blackish lead color; _a_, end of tibia bearing a tenant hair, with the tarsal joint and large claw; _b_, spring; _c_, the third joint of the spring, with the little spine at the base; figure 163, the supposed ovipositor; _a_, the two blades spread apart; _b_, side view. The mouth-parts in this genus are much as in Tomocerus, the maxillae ending in a lacinia and palpus. [Illustration: 173. Lipura fimetaria.] The three remaining genera, Lipura, Anurida and Anura, are placed in the "family" Lipuridae, which have no spring. Lubbock remarks that "this family contains as yet only two[13] genera, Lipura (Burmeister), in which the mouth is composed of the same parts as those in the preceding genera, and Anura (Gervais), in which the mandibles and maxillae disappear." Our common white Lipura is the European L. fimetaria Linn. (Fig. 173, copied from Lubbock). The site of the spring is indicated by an oval scar. [Illustration: 174. 176. 175. Anurida maritima.]