PRELIMINARY NOTICE OF NEW JAPANESE 

 ECHINO! DS. 



By s yoshiwaka. 



Zool. Inst., Science Coll., Imp, Univ , Tokyo. 



Since the publication of my paper on Asthenosoina in Vol. I, Part I oi this 

 periodieal I have found many new species of echinoids from various part- of 

 Japan. The following contains an account only of their important diagnostic 

 characters. The full paper will be published afterwards, with illustrations. 



1. Cidaris {Slereocidari*) IciiuisjÄuus, nov. sp. 



The general appearance of test and the form of spine at once distinguish 

 this species from other known members of the genus. Test is regularly arched 

 on abactinal side, but actinally it becomes suddenly curved from ambitus, and 

 has a slight concavity near peristome. The color of membrane is dark brown. 

 Basais are almost equal in both height and breadth, radiais distinctly excluded 

 from basais. The interambulacrum is three times as wide as the ambulacrum. 

 The scrobicular area is elliptical in form even at ambitus. The miliares in each 

 interambulacral plate are very few. The interporiferous area of ambilacrum 

 carries four regularly arranged vertical rows of tubercles. The primary spines 

 are slender. The fully developed one appears from 3rd or 4th interambulacral 

 plate, so that the whole abactinal side seems to be almost devoid of primary 

 spines. The first is longest having the length of 47 mm. and a uniform breadth 

 of 15 mm., in a specimen having the test of 35 mm. in diameter. All spines arc 

 grey and very indistinctly striated on the surface, and some being <|uite smooth. 

 Those near peristome are flattened, but never crcnulated. The miliary spines are 

 very small, with a thick brownish membrane at the base. 



Loc. ; Sagami Sea. 



2. Cidaris (òlereocidari?) microlabercidatus, nov. sp. 

 This greatly resembles S. grandi*, Dód. But each basal plate has a dis- 



