230 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 8 



Galapagos), but not at great depths. Mortensen reports it in 45 fms in 

 the Gulf of Panama, while the Velero took specimens at depths of 62-76 

 fms of? Angel de la Guardia Island in the Gulf of California. The most 

 northerly point from which it is reported is near Consag Rock in the Gulf 

 of California. It is noteworthy that it has not been taken along the western 

 coast of Lower California. Its southern limit, on the continental coast, is 

 La Plata Island, Ecuador. It is very common among the Galapagos 

 Islands where the Velero collected specimens at no fewer than 70 stations. 



Type. — Paris Museum? 



Type locality. — "Californie (Neboux.) Galapagos." 



Depth. — Shore to 76 fms. 



Specimens examined. — 1,201 specimens from 175 stations. 



Hesperocidarls panamensis (A. Agassiz) 

 Plate 35, Fig. 2 



Dorocidaris panamensis A. Agassiz, 1898, p. 73; 1904, p. 20, pis. 1-4. 

 Hesperocidaris panamensis Mortensen, 1928, pp. 73-74; 1928a, Mon. 

 Ech. p. 416. 

 The material hitherto known of this sea-urchin consists of a few 

 specimens taken by the Albatross in 1891 and now distributed in the U.S. 

 National Museum, the Museum of Comparative Zoology and the British 

 Museum. The Velero, however, has secured no fewer than 84 specimens, 

 ranging from 4 to 49 mm in diameter ; the height of the test is about half 

 as much or a little more; both the upper and lower surfaces are definitely 

 flattened. The very young individuals are white orally but more or less 

 light coral red above ; the primary spines are whitish with a tinge of red 

 (at least basally) and have one or two ill-defined dusky bands and orange- 

 red or flesh-red collar. In one specimen from the Galapagos Islands 

 (Station 183-34) in 50-70 fms, the primaries are white except for more 

 or less of the tip which is to some extent dusky or reddish ; the contrast 

 between such primaries and the dull red secondaries is striking. With 

 increasing size, however, the primaries become unicolor, gray or brown- 

 ish, save for the collar, and rapidly increase in darkness until in adults, 

 they are deep brown or brownish purple, except where more or less in- 

 crusted with bryozoa, or other symbiotic forms. As a rule incrusta- 

 tion is not extensive and the primaries are slightly flattened at the tip. 

 In young specimens the collar tends to be conspicuously orange red, but 

 with age the color deepens and in adults is dark red or even reddish 

 purple of a very dark shade. The secondary spines are brownish red in 

 small specimens but become dark, almost a deep blood red in adults. 

 A full grown specimen is thus a very striking and rather handsome urchin. 

 In some individuals the young primaries at the upper end of each series 



