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ECHINOIDEA. I. 



Species: Sf. variolaris (Laink.), atropurpurea Woods (?). 

 Distribution: Indian Ocean, Australia. Littoral forms. 



Fam. Echinidae Ag. (emend.) 



Spicules bihamate. The globiferous pedicellarise with end-tooth and one or more lateral teeth 

 on either side; no neck; the stalk consists of long, thin, loosely connected calcareous threads. Mouth 

 slits small. 



Subfam. Parechininae n. subfam. 



In the globiferons pedicellarise the edges of the blade are fine, not thickened, and project into 

 two or more teeth on either side. No cross-beams connect the edges across the inside of the blade. 



Genera: Par echinus, Loxcchinus. 

 Parechinus n. g. 



Pores tri geminate; primary tubercle on all the ambulacral plates. The buccal membrane with 

 numerous fenestrated plates; they may be very large and thick, or finer and hidden in the skin. The 

 globiferous pedicellariae without neck. Numerous short, greenish spines. 



Species: Parech. miliaris (Mull.), microtubcrcula-tus (Blv.), anguloszts (Leske). 



Distribution: In the Atlantic Ocean at the European coasts, the Mediterranean; the southern 

 and eastern coasts of Africa; the Indian Archipelago, Australia. Littoral forms. 

 Loxechinus Desor (emend.). 



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

 with numerous fenestrated plates. The globiferous pedicellarise witli a short neck only containing 

 longitudinal muscles. Numerous short, greenish spines. 



Species: L. albus (Mol.), gibbosus (Val.), bullatus (Bell). 



Distribution: The southern and western coasts of South America, the Galapagos Islands'). 

 Littoral forms. 



Subfam. Echininse n. subfam. 



In the globiferous pedicellarise the edges of the blade are thickened and commonly connected 

 by cross-beams across the inside of the blade. One or more lateral teeth on either side. 



Genera: Echinus, Sterechimts, Paracentrotus. 

 Echinus Rond. (emend.) 



Pores trigeminate; primary tubercle on every or only on every other ambulacral plate. No 

 ocular plate reaches to the periproct. The buccal membrane with numerous fenestrated plates 

 imbedded in the skin both outside and inside of the buccal plates. The spines upon the whole long 

 and strong; the actinal primary spines not curved at the point. Globiferous pedicellarise generally 

 with the edges connected across the inside of the blade. The large, generally long and narrow, 

 tridentate pedicellarise with thick edge upon which numerous small teeth are placed in transverse 

 series or irregular!}'. 



*) The occurrence of L. albus at the Philippines and of gibhosus at the Fiji Islands needs corroboration. 



