Mayer, Sars and others in that they lack the pair of serrated spines at the base of the palm. Finger stout and half as long as the palm. Length of specimen, 12 mm. Color white or flesh color. The specimens were collected during the latter part of July at Laguna Beach, from the seaweed in the inner tide pools. _Caprella æquilibra_ Say The peræon (Plate IV, Fig. 12) is comparatively smooth, with the cephalon devoid of a horizontal spine; the first three segments are long and narrow, of nearly equal length, the fourth a little longer than the third, the fifth twice as long as the sixth and seventh combined. The branchia are ovate in shape and moderate in size. Between the bases of the second gnathopods is a sharp projection (Fig. 13), and on each side another spiniform process pointing anteriorly. Superior antennæ slightly over half as long as the body, first joint about half as long as the second, but broader; second twice as long as the first, and third a little longer than the first, but narrower; flagellum with sixteen or seventeen joints and about as long as the peduncle. Inferior antennæ reaching just beyond the peduncle of the superior. First gnathopod small, attached far forward, palm triangular in shape, tapering toward the finger, which reaches back entirely over the inner margin of the palm, armed with two sharp spine-like teeth at the base of the palm, and scattered hairs. Second gnathopod (Fig. 14), attached at the posterior end of the segment, basal joint quite short; other joints have their lobes ending in spine-like processes; palm slightly convex on the inner margin, with a spined lobe about a third of the way along, and a blunt tooth two-thirds of the way along separated from a broad tooth by a deep sinus; claw regularly concave; whole gnathopod with but few hairs. Third, fourth and fifth peræopods (Fig. 15) similar in size and structure; palm thick, with two serrate teeth a third of the distance from the base. Length of specimen, 12 mm. Color a dark brown to flesh color. Two specimens taken on a holdfast that was thrown up on the beach at Laguna Beach during July, 1914. BIBLIOGRAPHY _Bate, C. S._ 1862 Catalogue of Amphipodous Crustacea, pp. 357, 362. _Holmes, S. J._ 1903 Synopses of North American Invertebrates, xviii, The Amphipoda. The American Naturalist, vol xxxvii, No. 436, p. 291. Bulletin of Bureau of Fisheries, vol. xxiv, Amphipoda of Southern New England, p. 526. _Mayer, P._ 1882 Fauna und Flora des Golfes von Neaples, vi, Monographie, pp. 45-50. _Mayer, P._ 1890 Fauna und Flora des Golfes von Neaples, xvii, Monographie, pp. 48-57.