376 HAWAIIAN AND OTHER PACIFIC ECHINI. 



PODOPHORA. 



L. Agassiz, 1840. Cat, Syst. Ectyp. Echinod., p. 19. 

 Type-species, Echinometra atrata de Blainville, 1830. Diet. Sci. Nat., LX, p. 206. 



As this genus and the following have been so fully discussed in a recent 

 Monograph (A. Agassiz, 1908, Mem. M. C. Z., XXXIX), it would be quite 

 superfluous to go into any details here. There are two distinct species in 

 the genus, one of which (atrata) is wide spread in the Indo-Pacific region, 

 ranging from Zanzibar to Hawaii, while the other (pedifera) is confined, so far as 

 known, to the southeastern Pacific. 



The two species are readily distinguished from each other as follows : - 



Color abactinally, usually deep purple, rarely greenish; marginal primary spines with 

 rounded, sometimes swollen ends, not forming a close-set, even margin; actinal 

 petaliferous areas of ambulacra moderately developed, not abruptly constricting 

 the interambulacral spaces; pore-pairs at ambitus in arcs of 9 or 10 atrata. 



Color, abaetinally olive-green; marginal primary spines with flattened, chisel-like tips, 

 forming a close-set, even margin; actinal petaliferous ambulacral areas greatly 

 developed, abruptly constricting the interambulacral spaces; pore-pairs at ambi- 

 tus in arcs of 10-12 pedifera. 



Podophora atrata Agass. 



Echinus atratus LinnS, 1758. Syst. Nat., ed. 10, p. 655. 



Podophora atrata L. Agassiz, 1840. Cat. Syst. Ectyp. Echinod., p. 19. 



"Colobocentrotus Quoyi Brandt," A Agassiz and Clark, 1907. Bull. M. C. Z., L, p. 240. 



This appears to be one of the common and characteristic sea-urchins of the 

 Hawaiian Islands, and was found by the "Albatross" in considerable numbers 

 particularly at Puako Bay, Hawaii. A collector's note with a jar of specimens 

 from this place reads as follows: 



"Common on rocks along shore. Live in little depressions, the border spines 

 acting as the edge of a sucking disk. Dorsal surface very deep Indian purple 

 or prune-purple when in the water. By reflected light, out of water, almost 

 black. Underside of big spines, mauve. Circumoral membrane and membrane 

 between clumps of small spines and tubefeet, orange-red. Small spines and 

 tube-feet, light brownish, occasionally red or purple." 



Necker Island, Hawaiian Islands. 



Kamalino Bay, Niihau, H. I. 



Napili Harbor, Maui, H. L, "Albatross" St. 3881. 



Napili, Maui, H. I. 



