The present paper is based upon a collection of Phalangiidae kindly sent me at various times during the last three years by my brother, Mr. Howard Evarts Weed, of the Mississippi Agricultural College. Nearly all of the specimens were taken in the vicinity of the College, which is located in Oktibbeha County, a little north of the center of the State, so that the northern and southern extremities of Mississippi are not represented. This probably accounts, in part at least, for the fact that in

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... e large number of specimens collected only three species are found. The most remarkable thing connected with these phalangiids is the large size of their bodies and the length of their legs. Each form is the southern representative of a northern species in which the body is smaller and the legs are larger. I presume this variation in size is due to the longer period of growth and feeding at the south, but the discussion of variations is not the purpose of the present paper. Family PHALANGIIDAE. Subfamily PHALANGIINAE. Arachnids having the body composed of a single piece, and long, slender legs. The teguments are not coriaceous, though often quite solid. The seglnents are only indicated by striae, which are often obsolete. There are five ventral abdominal segments a single anal piece, and two distinct lateral pores on upper margin of cephalothorax. The maxillary lobe of the palpus has two tubercles. The two eyes are placed upon a blunt tubercle (the eye-eminence) on the median line of the cephalothorax not far from its front margin. The three Mississippi forms all belong to the single genus Liobunum, the principal characters of which are the following :--Anterior and lateral borders of the cephalothorax smooth. Eye eminence relatively small; smooth, or rarely provided with small, slightly distinct tubercles; widely separated from the cephalic border. Lateral pores small, oval, and marginal. Anal piece large, transverse-oval or semi-circular, much wider than long. Mandibles short, similar in the two sexes; first joint furnished at the base below with an acute tooth. Palpi simple; femur, patella and tibia without any process and without projecting angles; maxillary lobe provided at the base with two strong, conical teeth. Maxillary lobe of the second pair of legs very long, nearly straight from the base, not attenuated, directed mesad nearly horizontally, and united on the ventromeson to the lobe from the opposite side without forming a sensible angle; the two together lightly arched on the cephalic border, and forming an even curve. Sternal piece large, slightly contracted between the