1913.] Clark, Echinoderms from Lower California. 221 



wish to correct, so far as possible, the errors concerning the Echini. The 

 Arbacia siellafa recorded is undoubtedly from somewhere in the Panamic 

 region, on the west coast of Central America or Mexico, or in the Gulf of 

 California. The same is true of the Diadema mexicanum, Toxopncustcs 

 scmitubcrculatus and Clypeaster rotundas. As near as can be determined 

 now the "Echinometra oblonga" was an Echinometra lucurder from the West 

 Indies but as the specimen seems to be no longer extant, the matter cannot 

 be positively determined. 



None of the Arbacias in the present 'Albatross' collection are adult, the 

 largest being only 17 mm. h. d. 



San Josef Island, Gulf of California. 



San Esteban Island, Gulf of California. 



Agua Verde Bay, Gulf of California. 



Twelve specimens. 



Lytechinus anamesus. 

 H. L. Clark, 1912. Mem. M. C. Z., Vol. 34, p. 254. 



This recently described species was met with at only one place, although it 

 is widely spread in the region. The largest specimen is very much larger 

 than any previously known, measuring 37 mm. h. d. and 23 mm. high. 



San Bartolome Bay, west coast of Lower California. 



Off Pt. San Bartolome, west coast of Lower California, with "boat- 

 dredge." Depth not given. March 14, 1911. 



Six specimens. 



Lytechinus pictus. 



Psarnmechinus pictus Verrill, 1867. Trans. Conn. Acad. Vol. 1, p. 301. 

 Lytechinus pictus H. L. Clark, 1912. Mem. M. C. Z., Vol. 34, p. 258. 



All of the specimens are young, the largest only about 16 mm. h. d. 



"Lower California." 



Agua Verde Bay, east coast of Lower California. 



Twenty-six specimens. 



Strongylocentrotus fragilis. 



Jackson, 1912. Mem. Boston Soc. Nat. Hist., Vol. 7, p. 128. 



This is still another species represented only by young specimens, the 

 largest only about 40 mm. h. d. 



