Mr. F. M'Coy on some new Mesozoic Radiata. 417 



the two anterior ones, usually so small, being only the width of 

 one of the ambulacra less than the lateral ones in width. 



Great oolite near Minchinhampton. 



Inferior oolite near Castle Ashby. 



{Col. University of Cambridge.) 



Clypeus excentricus (M'Coy). 



Sp. Char. Orbicular, depressed (length and width each 3 inches 

 11 lines, height 1 inch 2 lines), posterior end slightly produced 

 and sinuate ; anal sulcus deep ; vertex nearly one-fourth of the 

 length nearer the posterior than the anterior end ; mouth small, 

 a little excentric towards the anterior end; ambulacra very wide; 

 granulation as in the C. patella. 



This species differs from the C. sinuatus (Park.) by the vertex 

 being so much nearer one end than the other, and from the C. 

 patella by its much greater depression. 



Abundant in the inferior oolite of Leckhampton. 



(Col. University of Cambridge.) 



Clypeus alius (M'Coy). 



Sp. Char. Subhemispherical, base nearly circular, posterior in- 

 terambulacral space slightly produced in the middle and sub- 

 truncate ; length and width equal (each about 1 inch 9 lines), 

 height half the width ; upper surface evenly convex ; oral disc 

 strongly undulated towards the margin by the convexity of 

 the interambulacral spaces and the depression of the ambula- 

 cra ; vertex central, with a very narrow, deep anal sulcus ex- 

 tending from thence to the margin where it is slightly dilated 

 and spoon-shaped ; mouth small, a little in front of the middle, 

 indented by the five tumid ends of the interambulacra ; ambu- 

 lacra narrow, upper two-thirds of their dorsal portion petalloid, 

 lower third and oral portion of parallel rows of unconnected 

 pores. 



In form and undulation of the base this resembles the C. Hugi 

 (Ag.), but is distinguished by the narrow anal sulcus extending 

 quite to the vertex, instead of being confined to the margin ; the 

 deflected lip-like projection of the posterior interambulacral space 

 is very remarkable. 



Common in the inferior oolite of Bridport. 



(Col. University of Cambridge.) 



Ann. $ Mag. N. Hist. Ser. 2. Vol. ii. 29 



