134 



ECHINOIDKA. I. 



Species: S/. variolaris (Laink.), atroptirpurea 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, looselx' connected calcareous threads. Month 

 slits small. 



Subfam. Parechininae n. subfam. 



In the globiferous 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 : Parcchinns^ Loxtxhiiiiis. 

 Parechinus n. g. 



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

 numerous fenestrated plates; thev ma\' be very large and thick, or finer and hidden in the skin. The 

 globiferous pedicellarise without neck. Numerous short, greenish spines. 



Species: ParrcJi. iniliaris (^liill.), iiiicrotubcrcitlatus (Kh'.), aiignlosns (Leske). 



Distribution: In the Atlantic Ocean at the Eiiropean 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. Tlie buccal membrane 

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

 longitudinal muscles. Nunaerous short, greenish spines. 



Species: L. albiis (Mol.), gibbosus (\'al.), bulla fns (Bell). 



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

 Littoral forms. 



Subfam. Echininas n. subfam. 



In the globiferous pedicellarise the edges of the blade are thickened and commonh- connected 

 !)>• cros.s-beams across the inside of the blade. One or more lateral teeth on either side. 



Genera: Echinus, Slerccliiiius, Paraccntrottis. 

 Echinus Rond. (emend.) 



Pores trigeminate; primary tubercle on ever\- or onl\- on e\-er\- other ambulacral ])late. No 

 ocular ])late 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 ])rimar\- spines not curved at the jioint. Globiferous pedicellarise generall\' 

 with the edges connected across the inside of the blade. The large, generall\- long .-uul narrow, 

 tridentate pedicellarise with thick edge upon whicli numerous small teeth are placed in trans\erse 

 series or irregularlv. 



•) The occurrence of L. albus at the riiilippines and of gibbosjis at the Fiji Ishiiuls needs corroboration. 



