52 MESOZOIC RADIATA. 



Chrysaoi'ci similis (M^Coy). 



Sp. Char. Corallum forming depressed rounded masses (usually 

 about halt' an inch in diameter) ; upper convex surface with 

 numerous small conical projections, generally rather less than 

 a line apart, from which small, irregularly branching ridges 

 radiate ; the projecting points and ridges seem nearly solid and 

 smooth, the intervening spaces coarsely punctured by the 

 closely-placed openings of the minute cells. 



This is so closely allied to the Ceriopora [Chrysaora) venosa 

 (Gold.) of the Essen greensand that I scarcely can define their 

 difference ; the figures of Goldfuss of this latter species are both 

 2| diameters larger than nature, but making this allowance the 

 character of the surface is nearly the same in both ; the present 

 oolitic coral seems however to be constantly smaller and more 

 delicate in all its parts, and forms smaller and more depressed 

 masses. 



Great oolite. Not uncommon at Minchinhampton, 



{Col, University of Cambridge.) 



ECHINODERMATA. 



Crinoidea. 

 Bourguetiannus cylindricus (M'Coy). 



Sp. Char. Column elliptical j body cylindrical, scarcely exceeding 

 the stem in diameter, composed of four upper columnar joints 

 of equal diameter, but the two upper thinner than the third, 

 the fourth nearly double the thickness of the third, round in 

 its upper half, abruptly compressed and elliptical in the lower 

 half ; on the upper columnar joint rest five pentagonal pelvic 

 plates nearly equalling it in depth; between the upper lateral 

 angles of these are five exceedingly small, pentagonal j?rs^ radial 

 plates not half the depth of the pelvic plates. Length of body 

 to base of fourth columnar joint 9|^ lines, diameter 3^ lines : 

 articulating surface of columnar joints perfectly smooth, having 

 a thickened external rim and a mesial transverse articular ridge 

 perforated in the middle by a minute alimentary opening. 



This is so strongly marked in all its characters that a compa- 

 rison with other species is scarcely necessary : the " straight 

 encrinite ^' of Parkinson (B. cequalis, D'Orb.) is easily distin- 

 guished by the above characters. 



The nearest approach to it that I Khv'e seen is the so-called 

 Eugeniacrinites Hagenowii (Gold.), figured by Dr. Hagenow in 

 his memoir on the " Riigenschen Kreide-Versteinerungen " in 

 Leonhard and Bronn's ' Jahrbuch ^ for 1 840. The latter fossil, 



