ECHINOIDEA. I. 137 



Species: Tri'pii. rsctclentus (Leske), deprcssiis Ag., gratilla (L.). 

 Distribution: Cosniopolitan in the warm zone. Littoral fonns. 



Sphærechinus Desor (emend.). 



Pores iniiltigeininate (generally fonr in each arc); primary tnbercle on all the ambnlacral 

 plates')- Slits of the test rather deep; the bnccal niembrane with rather nnmerous fenestrated piates; 

 no spines on these or on the bnccal piates. In the globiferons pedicellariæ the blade is not nmch 

 lengthened. The spicules of the globiferons pedicellariæ small bows, not pointed at the ends; they 

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

 almost globnlar. 



Species: Spbærcclt. grainilarix (Lamk.), rosens Rnsso, australier Ag. 



Distribntion: Tlie Mediterranean and the adjoining Atlantic coasts, Anstralia. Littoral forms. 



Pseudoboletia Troschel (emend.). 



Pores mnltigeminate (fonr in each arc); jjrimary tnbercle on all the ambnlacral piates. Slits 

 of the test rather deep. The bnccal membrane with rather nnmerons piates carrying both spines and 

 pedicellariæ; spines are likewise fonnd on the bnccal piates. In the globiferons pedicellariæ the blade 

 is not mnch lengthened. The spicnles of the globiferons pedicellariæ small bows, not i)ointed at the 

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

 rather short-spined forms. 



Species: Fs. uidiaiia (Micli.), inaculata Trosch. 



Distribntion: The Indo- Pacific Ocean. Littoral forms. 

 Pseudocentrotus n. g. 



Pores mnltigeminate; primary tnbercle on all t!ie ambnlacral piates. The pore areas some- 

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

 ons fine fenestrated piates; no spines on these or on the bnccal piates. In the globiferons pedicellariæ 

 the blade is not mnch lengthened. The spicnles of the globiferons pedicellariæ bow-shaped, not 

 pointed at the ends; the\- form no border. The bihamate spicnles in the tnbe feet are branched. The 

 spines rather long and strong; the test rather flat. 



Onlv one species known: Ps. dcprcssus (Ag.). 



Distribntion: Japan. Littoral form. 



Subfam. Strongylocentrotinæ n. subfam. 



The spicnles of the globiferons pedicellariæ bihamate (alwajs?), generally branched at the ends; 

 no dumb-bell-shaped spicnles, nor snch as are not pointed at the ends. The globiferons pedicellariæ 

 with well developed neck with longitndinal and circnlar mnscles; tnbnlar stalk. 



Genera: Strongylocrnfrotiis, AiitJiocidaris. 



Strongylocentrotus Brandt (emend.). 



Pores mnltigeminate; the pore areas not petaloid on the actinal side. Primary tnbercle on 

 all the ambnlacral piates. The bnccal membrane with nnmerons fine fenestrated piates most of 



') Not examined in Spli. auslraliæ. 

 The Ingolf-Expedition. IV. i. lj> 



