56 MESOZOIC RADIATA. 



Width of each side 1 inch 3 lines ; length of marginal ossicles 

 3 lines. 



The straightness of the sides, and all the marginal ossicles 

 (except the eye-plates) being of one size, so that the inner and 

 outer boundaries of each row form two straight, parallel lines, 

 distinguish this species, which is, I think, only likely to be con- 

 founded with the G. regularis (Park, sp.) ; I have good specimens 

 of this latter now before me, and it is distinguished from the 

 present species by having the margin of the sides convex out- 

 wardly, and the middle marginal plates being considerably the 

 largest, the others decreasing rapidly in size towards the angles, 

 so that the row of plates instead of being rectilinear and parallel- 

 sided is clearly elliptical : this character is represented in Park- 

 inson's figure, but not to the extent to which it is seen in nature, 

 from the inner ends of the ossicles in his specimen being mani- 

 festly a little broken. 



Upper chalk of Norwich (two specimens). 



{Col. University of Cambridge.) 



Asterias (Astropecten) recta (M^Coy). 



Sp, Char. Hays five, straight, length from the base about three 

 times the width of the disc, widest at the base, tapering gra- 

 dually to the apex, with straight sides ; rows of lateral plates 

 averaging one -third the width of each ray (occupying rather 

 less at the base and rather more at the apex) ; they average 

 li line long and 3 lines wide, the long diameter or width di- 

 minishing gradually from the base to the apex ; angles be- 

 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 5J 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 ^ London 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 



