134 



ECHINOIDEA. I. 



Species: .S7. variolaris (Lanik.), atropurpurea Woods (?). 

 Distribution: Iiidian Ocean, Australia. Littoral forms. 



Fam. Echinidæ Ag. (emend.) 



Spicnles bihamate. The globiferoits pedicellariæ with end-tooth and one or more lateral teeth 

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

 slits small. 



Subfam. Parechininæ n. subfam. 



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

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



Genera: Parcc/iiiiits, Loxechiinis. 

 Parechinus n. g. 



Pores trigeminate; primary tubercle on all the ambulacral piates. The buccal niembrane with 

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

 globiferons pedicellariæ withont neck. Nnmerous short, greenish spine.s. 



Species: Parcch. luiliaris (MulL), iiiicrotubcrciilatiis (Bh-.), niignlosiis (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 nuiltigeminate; primary tubercle on all the ambulacral piates. The buccal membrane 

 with numerous fenestrated piates. The globiferons pedicellariæ with a short neck only containing 

 longitudinal muscles. Numerous short, greenish spines. 



Species: L. albiis (Mol.), gihboszis (Val.), bitllatus (Bell). 



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

 Littoral forms. 



Subfam. Echininæ n. subfam. 



In the globiferons pedicellariæ 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: Echiiiits, .Sfcrec/ii)ins^ Paracnitrotiis. 

 Echinus Rond. (emend.) 



Pores trigeminate; primary tubercle on ever}' or onh' on every other ambulacral plate. No 

 ocular plate reaches to the periproct. The buccal membrane with numerous fenesti'ated piates 

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

 and strong; the actinal primary spines not curved at the point. Globiferons pedicellariæ generalh- 

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

 tridentate pedicellariæ with thick edge upon whicli numerous small teeth are placed in transverse 

 series or irregularly. 



') The occurrence of L. albus at the Phihppines and of gibbostts at the Fiji Islands needs corroboration. 



