ECHINOIDEA. I. 



139 



Only one species: Pscudech. albocinctus (Hutton). 

 Distribution: New Zealand. Littoral form. 



Heliocidaris Desml. (emend.) 

 (Synonym: Evcchinns Verr.) 



Pores tri geminate; primary tubercle only on even' second or third ambulacral plate. The 

 bnccal membrane with numerous fine fenestrated plates hidden in the skin. No spines on the buccal 

 plates. The triphyllous pedicellarise with peculiar, digitate processes from the apophysis (in all the 

 other genera the triphyllous pedicellarise are constructed in the usual way). The spines short, strong, 

 greenish; the secondary spines club-shaped. The form of the test regular, Eckmus-^Sif. 



Species: H. chloroticus (Val.), raritiibcrculatus (Bell), australice Woods (? -- not examined). 



Distribution: New Zealand, Australia. Littoral forms. 

 Echinostrephus Ag. (emend.) 



Pores trigeminate, more rarely quadrigeminate; primary tubercle on all the ambulacral plates. 

 The buccal membrane with numerous fenestrated plates, most of which carry pedicellarise. No spines on 

 the buccal plates. The form of the test very peculiar, flat and broad above, narrow below. The spines 

 rather thin, black; those of the upper side long, directed straight upward. 



Species: Ech. molarc (Blv.), pcntagonus Yosh. (? -- not examined). 



Distribution: The Indo-Pacific Ocean. Littoral forms. 



Toxocidaris Ag. (emend.) 



Pores multigeminate; primary tubercle on all the ambulacral plates. The buccal membrane 

 with rather few plates most of which carry pedicellarige ; no spines on the buccal plates. The form 

 of the test regular, Echinus-like. The spines rather long and thick. 



Species: T. tuber culatus (Lamk.), erythrogrammiis (Val.), armiger (Ag.). 



Distribution: Australia. Littoral forms. 

 Echinometra Rond. (emend.) 



Pores multigeminate; primary tubercle on all the ambulacral plates. The buccal membrane 

 with numerous fine fenestrated plates hidden in the skin, of which only a few carry pedicellarise. 

 Spines on the buccal plates. The form of the test more or less oblong. The spines rather long 

 and thick. 



Species: Ech. lucunter (L.), viridis Ag., Mathaei (Blv.), oblonga (Blv.), van Brunti Ag., macro- 

 stoma (Ltk.) (?). 



Distribution: Cosmopolitan in the warm zone. Littoral forms. 



Heterocentrotus Brandt (emend.). 



Pores multigeminate; primary tubercle on all the ambulacral plates. The buccal membrane 

 with numerous fenestrated plates, partly hidden in the skin. Spines both on the buccal plates and on 

 some of the plates outside of these. The test oblong. The primary spines exceedingly large and thick, 

 mostly edged; the secondary ones short, truncate. 



Species: //. mamillatus (Klein), trigonariics (Lamk.). 

 Distribution: The Indo-Pacific Ocean. Littoral forms. 



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