Mr. F. M'Coy on some new Mesozoic Radiata. 409 



tween the rays acute; disc and middle of the rays closely 

 covered with blunt tubercles about fths of a line in diameter. 

 Each ray about 5^ inches long and 1 inch wide at base. 



This species is distinguished from the A. Aalensis (Miinst.) 

 and the A. arenicola (Gold.) by the very long, rigid, straight- 

 sided rays, there being no dilatation beyond the base as in those 

 species, as well as its greater size, perfect specimens being up- 

 wards of a foot in diameter, while the others are little more than 

 half that. The Astropecten Orion (Forb.) seems much allied, 

 but is a smaller species with longer rays, the interradial angles 

 obtuse, and the lateral plates square and much fewer in number. 

 The starfish figured from the same locality as this in Charles- 

 worth^s ' Loudon Geol. Journal,' no. 3. pi. 17, as the A. arenicola 

 of Goldfuss, agrees with the present species in every particular 

 save the dilatation of the rays beyond the base ; this character 

 exists clearly in the species of Goldfuss, which however is per- 

 fectly distinct by its shorter rays and other characters. I sus- 

 pected that in the English fossil alluded to, this appearance might 

 have been a fault of the artist ; Forbes however has I presume 

 seen the species, as he describes it (Mem. Geol. Survey, vol. ii. 

 part 2. p. 477) in accordance with this figure, also referring it to 

 Goldfuss's species, but without referring to the figure of that 

 author, which is most accurate. 



Not uncommon in the calcareous grit of Filey Brig, Yorkshire 

 coast. 



[Col. University of Cambridge : three specimens.) 



(Echinida.) 



Echinus petallatus (M^Coy). 



Sp. Char. Conoidal (diameter IJ inch, height 1 inch 2 lines), 

 base slightly contracted, obscurely ten-lobed ; ambulacral arese 

 half the width of the interambulacral, three oblique pairs of 

 pores in each row ; the ambulacral and interambulacral spaces 

 have each an elliptical, petal-like, concave, smooth space ex- 

 tending from the vertex nearly to the base, each space being 

 one-third the width of its respective area ; the upper two-thirds 

 of the ambulacral arese have but one row of large tubercles on 

 each side, surrounded by a circle of very minute granules; 

 towards the base where the smooth central space stops there 

 are four rows of large tubercles ; the upper third of the inter- 

 ambulacral spaces has but two rows of large tubercles with 

 their circle of small granules, but they gradually increase to- 

 wards the base, and at the end of the smooth space there are 

 about eight rows. 



This is allied to the E. gyratus (Ag.), but is distinguished by 



