138 ECHINOIDEA. I. 



which are quite hidden in the skin. The spicules bihamate, branched or unbranched. The test more 

 or less flattened. The spines very different, from short and fine to long and coarse ones. 



Species: Str. chloroccntrohis Brandt, pulcherrimus (Barn.), inter mcdius (Barn.), drobachicnsis 

 (O. F. Mull.), purpuratns Stimps., franciscanus (Ag.). 



Distribution: The Northern Atlantic, the Arctic Ocean (drobachicnsis); the Northern Pacific 

 Ocean (all the species). Littoral forms. 



Anthocidaris Liitken (emend.). 



Pores multigeminate ; the pore areas somewhat petaloid on the actinal side. Primary tubercle 

 on all the ambulacral areas. The buccal membrane with numerous fine fenestrated plates most of 

 which are quite hidden in the skin. The spicules in the tube feet biacerate, a little curved, with a 

 rather strong point in the middle of the convex side. The test somewhat flattened, the spines rather 

 long and strong. 



Only one species known: A. homalostoma Ltk. 



Distribution: Japan, China. Littoral form. 



Subfam. Parasaleninae n. subfam. 



The spicules of the globiferous pedicellarise bihamate, unbranched; those in the tube feet bia- 

 cerate with a couple of small processes on the concave side. The globiferous pedicellariee without 

 neck ; the stalk compact. Slits of the test small r ). 



Only one genus known: Parasalcnia. 



Parasalenia Ag. 



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

 numerous fine fenestrated plates; no spines on the buccal plates. The periproct covered by four large 

 plates. The test oblong. The spines long and strong. 



Species: P. gratiosa Ag., Pohlii Pfeffer. 



Distribution: The Indo- Pacific Ocean. Littoral forms. 



Fam. Echinometridae Gray (emend.) 2 ). 



The globiferous pedicellarise with end-tooth and one unpaired, strong lateral tooth; the edges 

 of the blade almost always connected by cross-beams across the inside; no neck. Only bihamate 

 spicules are found. Slits of the test small. The stalk of the pedicellarise compact. 



Genera: Pseudechinus, Hcliocidaris, Echinostrephus, Toxocidaris, Echinometra, Coloboccntrotus, 

 Heterocen trotus. 



Pseudechinus n. g. 



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

 naked with the exception of the buccal plates. The spines of a middle length, slender. The form 

 of the test regular, EcAtttus-Wtt. 



') Parasalenia Pohlii not examined. 



2 ) The name of Echinotnelradx is linguistically incorrect (Bell). 



