ioo jfirst annual Report 



NOTES ON THE CRUSTACEA OF LACUNA 



BEACH 



C. F. BAKER 



From the character of the coast at Laguna one would expect a 

 rich representation of the crabs, shrimps, prawns, and their allies, 

 and the richness of the crustacean fauna is most forcibly impressed 

 upon one by a little collecting. We took a great number of specimens 

 and species of crustaceans during this first summer, of which but a 

 very small proportion have as yet been worked up, especially among 

 the Entomostraca. A few of these latter I have examined in some 

 detail in cases where they happened to be conspicuous or to occur 

 in great numbers of individuals. Miss Stout lias done a considerable 

 amount of work on the Amphipoda of this locality, and Miss Stafford 

 on the Isopoda. They both accumulated a great wealth of material, 

 indicating a littoral fauna of great richness in these groups. 



The crabs, but few of which I have determined, are extraordin- 

 arily abundant. The tide-pools swarm with them, a stone turned 

 over frequently revealing a half dozen species at one time. One 

 small crab, apparently quite rare, was of peculiar interest because 

 it seemed to be always covered with a dense forest of small simple 

 sponges, perhaps indicating a symbiotic relationship. 



A number of species of parasitic copepods (three from one 

 shark) and isopods were taken, but these are as yet undetermined. 



MALACOSTRACA 



Order DECAPODA 



Epialtus productus Randall 



The young of the kelp crab are very common in the tide-pools 

 clinging to fucus and other brown algae, but mature specimens are 

 only to be found in the kelp beds. 



Loxorhynchus grandis Stimp. 



Large carapace shells of this deeper water crab are commonly 

 washed up on the beach. 



Cycloxanthops novemdentatus Lock. 

 Frequent under stones between tides. 



Lophopanopaeus leucomanus (Lock.) 



(Figure 53) 



Occasional under stones between tides. Examination of the ap- 

 pendages of the head of this species, in comparison with those of 



