ILaguna Marine Laboratory 143 



peduncle somewhat longer than the first joint and about three times 

 as long as the third joint. Antenna two about two-thirds as long 

 as antenna one; thirteen-jointed flagellum about one-half as long 

 as peduncle. Upper lip slightly hi-lobed. Mandibular palp ([iiite 

 large, second joint broader and longer than the third, both armed 

 with long, slender spines. Maxilla one with rather large, triangular 

 shaped inner plate, fringed with line seta? on the inner edge, and 

 armed with one compound, apical spine. Maxillipeds with outer 

 plates much larger than the inner, and carrying several compound 

 seta? along the apical margin, finely toothed and setose along the 

 inner margin ; palp long and strong. Pleopods rather large and 

 very much alike, the sub-equal rami bearing long, compound setae. 

 Tel son long. Pleon segments all toothed posteriorly. Length 5-7 

 mm. 



Laguua Beach, California. Frequent in kelp holdfasts from deep 

 water. Coll. V. B, Stout. 



Genus Acanthogrubia n. gen. 



Head without rostrum. Side-plates one to five well developed, 

 fifth the broadest and deepest. Antenna one not as long as peduncle, 

 with four-jointed accessory flagellum. Antenna two, two-thirds as 

 long as antenna one, with peduncle slightly longer than flagellum. 

 Mouth parts prominent. Upper lip broadly rounded. Lower lip 

 with well developed inner lobes, and bifid outer lobes with prominent 

 mandibular processes. Mandible normal, third joint of palp broadly 

 rounded at apex, and armed with numerous long seta?. Maxilla one 

 armed with ten apical spines, second joint of palp broad with several 

 spines on the apex and inner margin. Maxilla two outer plate the 

 broader; inner plate as long as outer and thickly fringed on inner 

 margin. Maxillipeds, outer plates large. Gnathopods one and two 

 subchelate, gnathopod two the larger. Pera?opods one and two long, 

 slender, second joint slightly expanded. Pera?opod three, second 

 joint expanded, broader than long. Peraxipods four airl five the 

 longest. Uropod three, outer ramus with two hooks. Telson short 

 and broad, armed only with set.T. 



This genus differs from Amphithoe in having an accessory flagel- 

 lum on the first antenna. It also differs from Paraf/nihin in having 

 a four-jointed instead of one-jointed accessory flagellum, in having 

 the flagellum of the second antenna not elongate, and the second 

 joint of the third peraeopod as broad as long. 



