60 HAWAIIAN AND OTHER PACIFIC ECHINI. 



Test more or less arched above; apical system at center; markedly con- 

 cave below; mouth pentagonal. 

 Poriferous areas slightly depressed with intervening parts of test usu- 

 ally elevated; interambulacra often form more or less evident keel- 

 like ridges proximally; pore-pairs in specimen about 7 mm. long, six 



to seven on each side crispus. 



Poriferous areas flush with surface of evenly arched test; pore-pairs 

 more numerous, about nine on each side of petal in specimen 5.5 



mm. long elegans. 



Petals more or less imperfect with one to five (rarely six) pore-pairs on each side. 



Glassy tubercles of test conspicuously high, numerous, rounded or bluntly pointed, 

 making surface of test very rough; test broad and flat; ocular pores smaller than 



genitals, though the difference may be very slight scaber. 



Glassy tubercles low, rounded and often few in number. 



( h-ul;ir pores nearly or quite as big as genitals grandiporus. 



Ocular pores much smaller than genitals. 



Test exceedingly flat, v. d. less (often much less) than .25 of test-length; 

 periproct near margin, distant from mouth twice its own diameter or 



more platytatus. 



Test not so flat; periproct more or less nearly midway between mouth and 

 margin. 

 Unpaired petal with about four pore-pairs on each side: diameter of 



mouth about twice that of periproct incertus. 



Unpaired petal with only one or two pore-pairs on each side; diameter 

 of mouth about three times that of periproct macrostomus. 



Echinocyamus provectus. 



De Meijere, 1903. Tijdschr. Nederland Dierk. Yer. Ber. 2. 8. p. 6. 



This species is known from four stations in the Dutch East Indies, in 50- 

 200 fms. and from the coast of New South Wales in 40-60 fms. 



Echinocyamus megapetalus, 1 sp. nov. 

 Plate 126, figs. 5-8. 



Length, 7 mm.; breadth, 5 mm.; height, 2.8 mm.: mouth. 1.5 X 1 mm.: 

 periproct not quite 1 mm. in diameter. Test high, but flattened aborally and 

 somewhat concave beneath. Apical system at center. Petals very distinct 

 and large; poriferous areas widely divergent, each with ten to fifteen pain 

 of pores. Periproct nearer to mouth than to margin. Genital pores larger 

 than ocular pores. Radiating partitions within test very well developed PI. 

 126, fig. 7). Auricles conspicuous in interambulacra. Ambulacra more than 



'/utyas = hip; -f- TriraXor = petal, in allusion to the OBUSUal size of the petals. 



