FOREIGN OOLITIC ACROSALENIAS. 257 



Acrosalenia Woodwardi, Wright, nov. sp. 



Test spheroidal, depressed ; ambulacral areas narrow, with two rows of small tubercles 

 placed very obliquely in the upper part, a single row of granules between them ; inter- 

 ambulacral areas four times as wide as the ambulacral, with few tubercles in each row ; 

 bosses large and rather prominent ; tubercles widely perforated ; apical disc moderate, four 

 and a half lines in diameter ; genital plates unequal, anterior pair largest ; ocular plates 

 small ; sur-anal plate composed of several pieces. 



Primary spines three inches and a quarter long, and one line and a half thick, some 

 three inches long, and less than one line in their greatest thickness ; tapering, and some- 

 times forked, at the extremity ; very finely striated, or granulo-striated on the surface. 



Secondary spines three lines long, slender, cylindrical, pointed, and striated. 



Dimensions. — Height (?) ; transverse diameter, thirteen lines. 

 Formation. — Cornbrash ? British ? 

 Collection. — British Museum. 



Acrosalenia Hunteri, Wright, nov. sp. 



Test conoidal ; ambulacral areas narrow, with two rows of small tubercles ; inter- 

 ambulacra with two rows of moderate-sized tubercles ; test very much elevated ; apical 

 disc absent ; its form, and excentral position, with the absence of semi-tubercles, at the 

 base of the ambulacra, indicate its acrosalenian character. 



Formation. — Unknown. I found this urchin in the celebrated John Hunter's collec- 

 tion. Not having access at present to the specimen, I am unable to give a more correct 

 diagnosis of its specific characters. 



Collection. — Hunterian Museum, Royal College of Surgeons, London. 



