1896.] 



MICROSCOPICAL JOURNAL. 



59 



unequal and filled up by an incomplete patagium, with 

 straight or slightly rounded edges, which extends to the 

 middle of the broadest part of the distal ends. 



Dimensions. — Radius of longer arms (without termi- 

 nal spine.) 0.15 m.m. 

 Breadth at their base 0.03 " 

 Distal breadth 0.06 " 

 Radius of central disk 0.03 " 



Habitat. — Fossil in the rocks of Barbados. 



Rhopalastrum{?) anornalum, 7i. sp. 



Distance between paired arms about nine-tenths (9-10) 

 as large as their distance from the odd arm. All three 

 arms wedge-shaped, gradually diminishing in breadth 

 from base to the distal part; odd arm somewhat larger 

 and broader at the base than the paired arms. In place 

 of central disk, two parallel lobes surmounted by a sec- 



