ECHINOIDEA. I. 



Species: Tripn. esculentns (Leske), dcprcssus Ag., gratilla (L,.). 

 Distribution: Cosmopolitan in the warm zone. Littoral forms. 



Sphaerechinus Desor (emend.). 



Pores multigeminate (generally four in each arc); primary tubercle on all the ambnlacral 

 plates'). Slits of the test rather deep; the bnccal membrane with rather numerous fenestrated plates; 

 no spines on these or on the bticcal plates. In the globiferous pedicellarise the blade is not much 

 lengthened. The spicules of the globiferous pedicellarise small bows, not pointed at the ends; they 

 form no border. In the tube feet branched, bihamate spicules are found. Large, short-spined forms, 

 almost globular. 



Species: Sphcercch. granularis (Lamk.), roscus Russo, australia Ag. 



Distribution: The Mediterranean and the adjoining Atlantic coasts, Australia. Littoral forms. 



Pseudoboletia Troschel (emend.). 



Pores multigeminate (four in each arc); primary tubercle on all the ambulacral plates. Slits 

 of the test rather deep. The buccal membrane with rather numerous plates carrying both spines and 

 pedicellarias ; spines are likewise found on the buccal plates. In the globiferous pedicellarise the blade 

 is not much lengthened. The spicules of the globiferous pedicellarise small bows, not pointed at the 

 ends; they form no border. The bihamate spicules in the tube feet are not branched. Large, high, 

 rather short-spined forms. 



Species: Ps. indiana (Mich.), macula fa Trosch. 



Distribution: The Indo- Pacific Ocean. Littoral forms. 

 Pseudocentrotus n. g. 



Pores multigeminate; primary tubercle on all the ambulacral plates. The pore areas some- 

 what petaloid on the actinal side. Slits of the test rather small. The buccal membrane with numer- 

 ous fine fenestrated plates; no spines on these or on the buccal plates. In the globiferous pedicellarise 

 the blade is not much lengthened. The spicules of the globiferous pedicellariae bow-shaped, not 

 pointed at the ends; they form no border. The bihamate spicules in the tube feet are branched. The 

 spines rather long and strong; the test rather flat. 



Only one species known: Ps. depressus (Ag.). 



Distribution: Japan. Littoral form. 



Subfam. Strongylocentrotinae n. subfam. 



The spicules of the globiferous pedicellarise bihamate (always?), generally branched at the ends; 

 no dumb-bell-shaped spicules, nor such as are not pointed at the ends. The globiferous pedicellarise 

 with well developed neck with longitudinal and circular muscles; tubular stalk. 



Genera: Strongylocentrotus, Anthocidaris. 



Strongylocentrotus Brandt (emend.). 



Pores multigeminate; the pore areas not petaloid on the actinal side. Primary tubercle on 

 all the ambulacral plates. The buccal membrane with numerous fine fenestrated plates most of 



') Not examined in Sph. australia. 

 The Ingolf-F.xpedition. IV. i. t g 



