_Legs_: Lack trochantins, III and IV stouter than I and II; mandibles large; serrula not attached throughout length of moveable finger; spinnerets long and transparent. _Habitat_: Claremont, Ice House Canyon, under leaves. _Ideoroncus obscurus_ Banks _Description_: Length of animal, including mandibles, 3 mm.; length of pedipalps, 3 mm. Color--Cephalothorax and pedipalps dark yellow brown; abdomen and legs very light yellow. _Cephalothorax_: A little longer than broad; front margin slightly truncate, rounded; sides so slightly convex as to be almost straight; lower margin slightly recurved; no transverse sutures; one pair of eyes. _Abdomen_: Elongate and slender; scuta entire; both abdomen and cephalothorax with a few simple scattered hairs. _Palps_: Long and slender; coxa smooth; trochanter lacks large protuberance of many of the Cheliferidæ; femur hardly as long as cephalothorax, very slender and not pedicellate; tibia shorter and broader than femur, pedicellate, convex on inner edge, only slightly so on outer edge; trochanter, femur, and tibia covered with short, stout simple hairs; claw long and slender; finger little longer than hand, and only slightly curved; hand twice as long as broad; hand and claw covered with long, simple hairs; mandibles large, serrula attached only at base; spinnerets long and transparent. _Legs_: The femur and tibia of the first two pairs of legs rather stout; no trochantins; covered with simple hairs. _Habitat_: Found in oak trees in the wash around Claremont. This differs slightly from that described by Banks in that: 1. The upper margin of the cephalothorax is not rounded, but truncate. 2. The fingers of the claw are not shorter than the hand. 3. The femur and tibia of the first two pairs of legs are not stout. (_Contribution from the Zoological Laboratory of Pomona College_) Some Points in the Nervous System of a Large Deep Water Crab WILLIAM A. HILTON During the summer of 1914 several living specimens of the large crab _Loxorhynchus grandis_ Stimp. were obtained at Laguna Beach. One of these was kept for some time in a tank of sea water, and its general movements were observed as it walked about on the bottom or attacked the sharks or other fish in the aquarium. Its movements were slow and its senses seemed not very acute in this situation. A gross and microscopical examination of the nervous system gave much the appearance of these organs in other decapods, but the remarkably small size of the brain or head ganglion was especially noticeable. The nerves connected with this ganglion were long and slender. The optic was large, the tegmental a little smaller and the first antennal about as large as this last. Closely associated with the optic was the small oculomotor, and near the connectives the small second antennal. Other small nerves were connected with the brain, whose courses were not traced, including a pair of small frontal nerves.