of the Pacific Shores of North America. 527 



six rows of larger tubercles, between which smaller ones are 

 interspersed ; the tubercles of the two rows next within the 

 exterior ones are largest. Auricles slender. Spines of 

 moderate length, rather stout and blunt. Color, deep pur- 

 ple. Diameter, 2| inches ; height, 1\ inch. 



Found at low-water mark on rocky ocean shores near 

 San Francisco. It is often sold in the market, being used 

 as food by some classes of the citizens, chiefly those from 

 Southern Europe. 



DENDRASTER EXCENTRICUS. Esch. 



Scutella excentrica, Eschscholtz ; ZoGlogischer Atlas, PL XX. f. 2. 

 Echinarachnius excentricus, Valenciennes ; Voy. Venus, Zotiph. PL X. 

 Dendraster excentvicus, Agassiz ; Cat. des Echinides, 77. 



This is the common cake-urchin of the coast, ^nd is 

 found at all points from Sitka to Monterey. 



ASTERIAD^E. 



ASTERIAS OCHRACEA. Brandt. 

 PL XXIII. f. 2. 



Asterias ochracca, Brandt ; Prod. desc. anim. Mertens, 69. 



Rays five, each scarcely twice as long as the disk is wide. 

 Larger dorsal spines capitate, somewhat reticulating, and 

 forming a pentagon at the middle of the disk which en- 

 closes the madreporic body. Diameter, eight inches. 



It is very common near San Francisco, on rocks at low- 

 water mark, and was also taken at Tomales Bay by 

 Mr. Samuels. It was originally found at Sitka. A. ian- 

 thina, Brandt, is probably only a variety. 



The figure represents a small portion of the upper sur- 

 face of one of the rays, to show the arrangement of the 

 spines. 



