86 U.S. NATIONAL MUSEUM BULLETIN 258 



corallina as the senior synonym of A. simulans because there is some 

 confusion over a possible phenotype of A. pollex. Specimens of that 

 phenotype have slender lobules on the lower lip but have been iden- 

 tified with A. simulans, nevertheless. Perhaps they represent a sibling 

 species similar to A. simulans or a hybrid between A. simulans and 

 A. pollex. The solution to this problem must be reserved until after 

 the life histories of the organisms have been studied. 



Cymadusa uncinata (Stout) 



Acanthogrubia uncinata Stout, 1912, p. 146, figs. 81-83. 



Paragrubia uncinata: Shoemaker, 1941b, p. 188. — Hewatt, 1946, p. 199. 



Cymadusa uncinata: J. L. Barnard, 1965a, p. 40, figs. 26-28. 



Material. — goleta: Macrocystis holdfast, 3 m. abundant. 



Distribution. — San Juan Islands, Washington, to Laguna Beach, 

 California. Apparently this is a northern species associated with giant 

 kelps; collections at hand made by Dr. Erik Dahl show it to be very 

 abundant in the Washington sound area. 



Pleonexes aptos, new species 



Figures 3-4 



Diagnosis of female. — Antenna 1 nearly as long as antenna 2, 

 peduncles of both antennae short in comparison to P. gammaroides, 

 peduncular article 5 of antenna 2 shorter than article 4; lateral cephalic 

 lobe truncated; mandibular palp small, article 3 much shorter than 

 article 2; lower lip with outer lobes strongly bilobed distally, lateral 

 bilobation very long; gnathopods small, second scarcely stouter than 

 first, palms very oblique and poorly defined from sloping posterior 

 margins of article 6, each bearing one striated defining-spine, fifth 

 article of gnathopod 2 with hind lobe more slender and projecting than 

 on gnathopod 1; second articles of pereopods 3-5 each with distinct 

 posteroventral lobe armed with one seta, sixth articles strongly ex- 

 panded and essentially subchelate, the false palms bearing 2 straight 

 proximal spines, followed distally by one large curved distal spine 

 adjacent to one much smaller straight spine, all spines and dactyls 

 striate; telson triangular, with 2 recurved, subacute, distal protrusions; 

 major spines of uropod 3 striate. 



Male. — Gnathopod 2 much larger than in female, article 6 nearly 

 twice as long as broad, palm oblique, quadrately convex, much shorter 

 than posterior margin of article 6, defined by one truncated, striate 

 spine; antenna 2 larger and longer than in female, articles 4 and 5 of 

 peduncle equal in length. 



Figure 3. — Pleonexes aptos, new species, holotype, female, 6.0 mm., station 48-H-l: 

 a,b,c,d, pereopods 1, 3, 4, 5; e, end of pereopod 4;/, telson; g,h, gnathopods 1, 2; i, coxa 4; 

 ;', maxilla 2; k, pleonites 1-3, left to right. Male, 7.0 mm., station 48-H-10: /, gnathopod 

 2; m, palmar spine of gnathopod 2. 



