146 U.S. NATIONAL MUSEUM BULLETIN 258 



be considered. Because the only specimen of M. martesia having a 

 first antenna is identified with reservations, the generic allocation 

 must remain dubious also. 



Material. — cayucos: PA^os^aefar-pelvetiid grid, abundant (209 

 per sq. m.) ; soft polychaete tubes, rare; sponge, moderately abundant; 

 Amaroucium sp., scarce. 



Distribution. — A southern species, described from Bahia Mag- 

 dalena, Baja California, apparently with its northern limits at 

 Cayucos, California; not collected in southern California, its abun- 

 dance at Cayucos possibly resulting from sea warming of the late 

 1950's or its existence as a northern disjunct. 



Eurystheus thompsoni (Walker) 



Eurystheus thompsoni (Walker): Shoemaker, 1955b, p. 59 (with synonymy). — 

 J. L. Barnard, 1959, p. 36, pi. 11; 1961, p. 182. 



Material. — carmel: algal holdfasts, rare; tunicates and sponges* 

 rare, cayucos: Phyllospadix-pelvetiid grid, scarce (168 per sq. m.) ; 

 buried cobbles, scarce; Macrocystis holdfast, abundant; sponge, rare. 

 hazard canyon: kelp holdfasts, moderately abundant; algal turf, 

 rare; Egregia-Laminaria holdfasts, moderately abundant; sponge, 

 scarce, goleta: Macrocystis holdfast, 3 m., abundant, pt. dume: 

 loose rocks, rare; sandy social tunicates, rare, corona del mar: 

 Phyllospadix-coraWine grid, rare (12 per sq. m.) ; loose rocks, rare; 

 calcareous worm tubes, moderately abundant; Egregia stipe, rare; 

 soft polychaete tubes, scarce; Laminaria holdfast, scarce; Phragma- 

 topoma masses, scarce; tunicates, scarce; Phragmatopoma masses, 

 most abundant species, la jolla: underrock grid, rare. 



Distribution. — A cold-temperate species of northeastern Pacific, 

 rare in intertidal of southern California, but moderately abundant 

 on coastal shelf benthos; Puget Sound, Washington, to the Gulf of 

 California, in southern Baja California as the variety lobata. 



Megamphopus effrenus J. L. Barnard 



Figures 32, 33 

 Megamphopus effrenus J. L. Barnard, 1964a, pp. 238-239, figs. 8, 9. 



Material. — cayucos: Phyllospadix-pelv etiid grid, scarce (92 pei 

 sq. m.) ; soft polychaete tubes, scarce, corona del mar: Phyllospadix- 

 coralline grid, scarce (8 per sq. m.) ; tunicates at base of Phyllospadix, 

 moderately abundant, la jolla: Phyllospadix-coraWme grid, moder- 

 ately abundant (142 per sq. m.) ; short-tufted red algae, scarce (44 per 

 sq. m.) ; underrock grid, rare; corallines, rare; mixed red algae below 

 water, scarce. 



Distribution. — La Jolla to Cayucos, California, intertidal. 



