Studies in Laguna Amphipoda. 657 



witli tlie palni and finger like 1. Pereiopod 1, second Joint widened. 

 Pereiopod 2 siinilar, but a little smaller. Pereiopods 3 — 5 sncces- 

 sively longer. Pleopods developed, not large, biramous. Uropod 1, 

 rami sliorter tlian peduncle; outer ramus broader and slightly 

 shorter thau inner; peduncle and outer ramus spinöse on outer 

 edges. Uropod 2, rami and peduncle about subequal in lengtli; the 

 inner a little longer and somewhat narrower. Uropod 3, tlie sub- 

 equal rami shorter than the peduncle ; the outer ramus shorter, with 

 two lioöks; the inner ramus with several short spines and longer 

 setae. Telson small, entire, longer than broad, apex rounded and 

 with a few setae on either side. 



Color, varying from olive green to tan. 



L. 4—7 mm. 



From coralline algae between tides. Laguna Beach, Calif. 



Ischyrocerus parvus n. sp. 



Body slender. Head not rostrate. Eyes small, on side-lobes 

 betwT.en the antennae. Side-plates not as deep as their segments; 

 third and fourth broadest and deepest; the fifth almost as deep as 

 the fourth; the sixth much shallower. Antennae 1 and 2 stout. 

 Antenna 1, peduncle with first Joint short and thick; second and 

 third much longer, subequal; peduncle longer than the five-jointed 

 flagellum; accessory flagellum two-jointed. Antenna 2, somewhat 

 longer than I; antepenultimate, penultimate, and ultimate joints of 

 peduncle successiveiy longer; peduncle longer than the 4 — 5-jointed 

 flagellum. Lower lip well developed with prominent mandibular 

 processes. Mandible with palp large, the second Joint longer than 

 the third, the third broadly rounded and setose ; cutting plates den- 

 tate; plumose spines in spine-row; molar normal. Maxiila 1, inner 

 plate small with two or three setae on the inner margin; outer 

 plate with nine or ten spines ; palp long, spinöse on the broad apex. 

 Maxilla 2, both plates apically fringed, the inner fringed on the 

 inner margin. Maxillipeds, inner plates small, setae and the usual 

 three spines on the apex; outer plates longer, with spines; fourth 

 Joint of the palp short. 



Gnathopod 1 of the male with the second Joint expanded distally ; 

 fifth nearly as wide, but much shorter than the sixth; palm long, 

 oblique, setose, with two terminal spines; finger long and serrate. 

 Onathopod 1 of the female similar to the male, palm serrate. 



