Two hitherto undescribed Species of Radidria. 425 



Art. VIII. A Notice of Two hitherto undescribed Species of Ra- 

 diaria, from the Marlstone of Yorkshire ; and Remarks on the 

 Organic Remains in that Stratum. By Mr. W. C. Williamson, 

 Curator to the Manchester Natural History Society. 



The occurrence of remains of Radiaria in the marlstone of 

 Yorkshire has been for some time known by the collectors 

 of fossils on that coast; but they have chiefly consisted, until 

 lately, of Ophiura Miller/ Phillips. A little time ago, there 

 were found traces, of an imperfect nature, of what was ap- 

 parently a true ^sterias, with five rays ; only, however, show- 

 ing the lateral papillae of the rays, which were sufficiently 

 distinct to prove its being different from Ophiura. The oc- 



currence of true v4steriae, however, was decided by the dis- 

 covery of the fossil now figured (7%. 63.), which was found in 

 Vol. IX. — No. 64. 1 1 



