88 j?ir0t Annual 



SOME ECHINODERMS COLLECTED 

 AT LACUNA 



C. F. BAKER 



Starfish, serpent stars, sea-urchins, and sea cucumbers are very 

 much in evidence between tides at Laguna, some species occurring 

 in enormous numbers. As yet, no special effort has been made to 

 collect the species thoroughly. Of most of those taken a set was de- 

 termined by Prof. Walter K. Fisher of Stanford University, and he 

 very kindly furnished the notes incorporated below under quotation 

 marks. 



HOLOTHUROIDEA 



Synapta inhoerens (). F. Mull 



These beautiful pale-colored little holothurians are frequent in 

 the sand under stones in tide-pools. Some of their movements are 

 extraordinarily worm-like. The peculiar character of the dermal 

 anchors and plates in this species are very distinctive. 



Stichopus californicus (Stimpson) 



The large brown sea cucumber is a common object in the tide- 

 pools. Some grow to eight and ten inches in length and even more. 

 We examined large numbers of them for commensals but did not 

 happen to encounter any. 



ASTEROIDEA 

 Linckia columbiae Gray 



The smooth red starfish is common in the tide-pools. Its capacity 

 for arm motion is very limited compared to other starfishes here, and 

 through frequent mutilations it is rarely normally armed. Prof. 

 Fisher says of it: "This curious little starfish is a member of the 

 Panamic fauna, the type having been taken on the west coast of 

 Colombia. It has been recorded previously from California at La 

 Jolla, San Clemente Island, Santa Catalina Island and San Pedro. 

 Miss S. P. Monks carried on some interesting studies on the varia- 

 bility and autonomy of this species. It is able to sever its arms, and 

 not only to regenerate new arms, but also to regenerate new disks on 

 the severed rays. The number of rays varies from one to nine, but 

 there are usually five. There may also be more than one madreporic 

 body, and as many as four anal apertures. Very rarely there are 

 two mouths." 



