GAMMARIDEAN AMPHIPODA 11 



pratti, Oligochinus lighti, and Atylus levidensus; and southern Cheri- 

 photis megacheles, Chevalia aviculae, and Ampelisca schellenbergi. Other 

 species of weaker northern or southern affinities occur in this sample 

 grid: northern Parallorchestes ochotensis, Parapleustes nautilus, Oco- 

 singo borlus, and southern Eurystheus spinosus and Megamphopus 

 effrenus. 



The Phyllospadix zone at Hazard Canyon reef occurs as a narrow 

 strip adjacent to the steeply sloping, wave splashed edge of the main 

 reef platform; the zone was not sampled effectively because many of 

 the underwater, hand scraped samples undoubtedly suffered washing 

 losses. For instance, only 10 species and 68 individuals of Amphipoda 

 were found in sample 42-T-9 (Appendix I), whereas an average of about 

 17 species and 400 individuals per sample occurred in the gridwork 

 at Cayucos. Only 20 species of Amphipoda were found in a sample grid 

 of the reef platform (table 8 and Appendix I). The amphipodan fauna 

 of Hazard Canyon, like that of one of the grids at Carmel, is dominated 

 numerically by Oligochinus lighti. Perhaps, this is a reflection of the 

 poor protection from surf and the reduction in density of plants. Some 

 of the numerically predominant species found at Carmel also occur 

 with Oligochinus at Hazard Canyon: Elasmopus rapax mutatus, 

 Parapleustes nautilus, and Parallorchestes nautilus. The latter two 

 species apparently occur most frequently under conditions of heavy 

 surf whereas those predominant species at Cayucos, Photis brevipes 

 and Calliopiella pratti, do not. Aoroides columbiae also appears to be 

 depleted in situations of heavy surf. Hyale grandicornis and Allorchestes 

 anceps, although not of high rank numerically, are conspicuous 

 members of the fauna at Hazard Canyon. 



The Phyllospadix-pelv etiid zone at Goleta (Coal-Oil Point) is very 

 small, impoverished, and quite unprotected from surf action, although 

 the shore faces south to the Santa Barbara Channel and is far more 

 protected from northwestern Pacific swells than the region between 

 Hazard Canyon and Monterey. Hyale rubra jreguens is extremely 

 abundant at Goleta (table 10) but its high ranking codominants are 

 Lysianassa macromerus, Jassa jalcata, Ischyrocerus sp. A, and Ponto- 

 geneia rostrata, an unusual combination of species. Jassa jalcata is 

 an ubiquitous harbor dweller often found in situations impoverished 

 of other species and thus it is a logical inhabitant of Goleta. But the 

 occurrence of a lysianassid amphipod, Lysianassa macromerus, is 

 striking. Although Lysianassidae are the most diverse family of 

 marine Amphipoda, their individuals are rarely abundant in any 

 situation (except in Polar seas). Presumably Lysianassa macromerus is 

 a deposit feeder and its frequency may be related to the partial inunda- 

 tion by sediments of the habitat at Goleta. The lysianassid may feed 

 on sediments trapped in pockets among leaves and clumps of Phyllos- 



