Mr. P. M'Coy on some new Mesozoic Radiata. 405 



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 first radial 

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

 to base of fourth columnar joint 9J 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 n of Parkinson (B. aqualis, D'Orb.) is easily distin- 

 guished by the above characters. 



The nearest approach to it that I have 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 1840. The latter fossil, 

 though I think probably referable to the present genus, is di- 

 stinguished as a species by the great depth of the two upper 

 joints of the dilated column. 



Rare in the upper chalk, Norwich. 



(Col. University of Cambridge.) 



Bourgueticrinus Milleri (M'Coy). 



There are two species confounded in England under the name 

 Apiocrinus ellipticus of Miller, by whom they are both figured 

 without distinction ; one with the first radial plates, about double 

 the depth of the pelvic plate which most of his figures illustrate, 

 is the one recognized by nearly all continental writers as this 

 species, and as such is figured as the type of the present genus 

 by D'Orbigny ; to it therefore the name B. ellipticus should be 

 retained. The other (fig. 1 of Miller's work) has the first radial 

 and pelvic plates about equal in depth, with the same club-like 

 figure ; this, which is more rare, but constant in its characters, 

 I beg to distinguish by the above name. 



Upper chalk, Norwich. 



(Col. University of Cambridge, &c.) 



Bourgueticrinus ooliticus (M'Coy). 



Sp. Char. Column much-compressed, of thin elliptical joints an- 

 gulated and obscurely tuberculated round the middle of their 

 outer edge j articular surface having a strong transverse ridge, 

 with a central boss perforated by the small alimentary canal, 



