18 U.S. NATIONAL MUSEUM BULLETIN 25 8 



serricatus, Ampithoe pollex, A. plumulosa, Micro jassa litotes, Aoroides 

 columbiae, Microdeutopus schmitti, and Photis brevipes. At Pt. Dume 

 only Aoroides columbiae and Ampithoe pollex are as frequent as they 

 are at La Jolla, and at Pt. Dume they occur with Lysianassa macro- 

 merus, an apparent indicator of sand inundation, and Parallorchestes 

 ochotensis, a species presumably near its southern limits in the area. 



Corallines are scarce at Carmel and Hazard Canyon but those 

 familiar amphipods, Hyale and Aoroides, dominate in conjunction 

 with Oligochinus lighti (a northern species) and Elasmopus rapax 

 mutatus. Parapleustes nautilus appears to have a strong positive 

 association with corallines in middle California. 



Dense, almost pure stands of various species of corallines occur in 

 many places in southern California but few Amphipoda are confined 

 to them obligatorily. Indeed, the amphipodan fauna of coralline 

 substrates is poorly diverse in contrast to the faunas of Phyllospadix- 

 stands, kelp holdfasts and some of the larger masses of sponge and 

 arenaceous polychaetes. Only 5 species of Amphipoda appear to have 

 a strong association with corallines: Amphilochus ^litoralis (also on 

 stipes of Egregia), A. neapolitanus , Ampithoe plumulosa, Pontogeneia 

 quinsana, and Stenothoe estacola. Only the latter species is obligatorily 

 restricted to corallines; the others are found in other situations, A. 

 plumulosa especially having been collected frequently on floating 

 docks in harbors. 



Interstitial rock nestlers, foulers, and sedimentary bur- 

 rowers. — The most conspicuous rock nestlers discovered in this 

 survey are the pale pink Maera vigota, n.sp., individuals of which were 

 lying partially desiccated between rocks in the intertidal of Cayucos. 

 Their clusters gave the appearance of colonies of pink encrusting 

 organisms. 



Sedimentary substrates under rocks are poorly inhabited by 

 Amphipoda. Samples from Cayucos (43-B-2, 43-C-l, 43-H-l), 

 Corona del Mar (table 20), and La Jolla (table 22 and Appendix I) 

 are representative. At La Jolla the underrock substrate is dominated 

 by Elasmopus rapax serricatus, Photis brevipes, and Microjassa 

 litotes. Six of the first 11 species of table 22 are tube dwellers, 4 are 

 nestlers, and one, Heterophlias seclusus, is an unusual member of this 

 habitat in view of the previously stated supposition that it is a woody- 

 algal burrower or scavenger. The only prominent sediment burrowers 

 in the intertidal are the several species of Paraphoxus, P. obtusidens, 

 P. spinosus, and P. stenodes. They are found primarily under rocks 

 on sands and fine sands. Tubes of domiciliary Amphipoda rarely 

 dominate a wave dashed rock to the extent they dominate pilings 

 in protected harbors (table 17). Presumably wave dash is too severe 

 for tube dwellers to colonize rocks unless protection has been estab- 



