NO. 5 CLARK : ECHINI OF WARMER EASTERN PACIFIC 265 



Family Strongylocentrotidae 



Loxechinus albus (IMolina) 

 Plate 43, Fig. 19 



Echinus albus Molina, 1782, p. 200. 



Loxechinus albus Desor, 1858, p. 136. 



Strongylocentrotus albus H. L. Clark, 1910, p. 347, pi. 12, fig. 1. 



This large sea-urchin of the western coast of South America is exten- 

 sively used for food along the Chilean coast as Tripneustes is in the West 

 Indies. In both cases it is the voluminous gonads which are eaten, com- 

 monly roasted in the "half-shell." The largest specimen taken by the 

 Velero is somewhat less than 100 mm h. d, but specimens 120 mm in 

 diameter are reported. Altogether only 23 specimens were taken. The 

 smallest is 16 mm in diameter, the largest 84. The parasitic crab, 

 (Pinnaxoides), which so often lives in the periproct of this sea-urchin and 

 the following, Caenocentrotus gibbosus, is evidently present in at least 9 

 cases. The color is pretty uniformly green in spite of being often more or 

 less bronzed over with red-brown. In specimens less than 20 mm h. d. the 

 tips of the spines may be quite red. But in none of the specimens that I have 

 ever seen is there any obvious reason why the specific name albus should 

 have been attached to this sea-urchin. 



Distribution. — The Velero met with this urchin only three times — 

 first in 1935 along the shore in Independencia Bay, again in 1938 in San 

 Juan Bay and Independencia Bay, and thirdly, a few days later further 

 north, among the Lobos de Afuera Islands. This extends the range from 

 the Lobos de Afuera Islands, northern Peru (6° 53' 50"), southward to 

 the Straits of Magellan. 



Type. — Unknown. 



Type locality. — Chile. 



Depth. — Shore to 40 fms. 



Specimens examined. — 23 specimens from 6 stations. 



Caenocentrotus gibbosus (L. Agassiz and Desor) 

 Plate 43, Fig. 20 



Echinus (Toxopneustes) gibbosus L. Agassiz and Desor, 1846, p. 367. 

 Caenocentrotus gibbosus H. L. Clark, 1912, p. 348. 



Grant and Hertlein, 1938, p. 29, pi. 10, figs. 3, 4. 



Mortensen, 1943, p. 321, pi. 34, figs. 3, 4; pi. 



63, figs. 7, 8, 11, 13,19. 

 This is another South American urchin which has not followed the 

 coast north of the equator but unlike the preceding species it has followed 



