476 PAL.EONTOLOGICAL REPORT OF GEOLOGICAL SURVEY. 



ASTEROCRINUS ( ? ) CORONARIUS. Lyon. 

 (Plate I. fig. 1, 1 a.) 



It is with a considerable hesitation that this remarkable and hither- 

 to unknown fossil is refered to Asterocrinus, as it has neither basal, 

 radial, or arm pieces. This unique- crinoidal fragment was found, with 

 others, associated with Pentremites obesus, Asterocrinus capitalis, - &c, 

 in the lower intercalated calcareous bed. of the millstone grit of Critten- 

 den county. This specimen is evidently the summit and part of the 

 abdominal cavity and walls of a crinoid, and is prov isionally refer- 

 red to Asterocrinus, which it greatly resembles, by the arrangement of 

 the tumid star-like points; seen in profile it resembles a ducal coronet 

 or crown. The body is pentagonal, having equal sides ; the angular 

 corners are removed ; an angular notch is provided, into which three 

 of the point pieces are inserted into the body. The point on the right 

 of the oral opening is joined to the body by an irregular line, nearly 

 straight ; that on the left is joined by a curved line, with an angular 

 deflection near the side farthest from the mouth. The marginal bor- 

 ders of the pointed pieces are raised, and the pieces are fluted about 

 two-thirds their length ; they are thick, heavy, and solid ; curved on 

 the lower side, and when resting upon the upper surface, present the 

 appearance of a thick last, from the instep to the toe. Within the 

 pointed pieces are arranged twenty-five polygonal pieces — those imme- 

 diately surrounding the mouth are convex, the others are concave ; the 

 outer series are larger ; two are hexagonal ; the others are imperfect 

 rhombs ; those within the point to the right of the mouth are small 

 and long; the others are still smaller, of pentagonal, hexagonal, and 

 triangular forms. A few of the small pieces surrounding the oral open- 

 ing have been lost. 



Mouth, sub-central. 



Lower surface. Between the pointed pieces are three angular-prom- 

 inences, and four angular depressions ; these are probably the articula- 

 ting surfaces to which the lower part of the body and calyx were join- 

 ed; above these notches and prominences, and on the surface between 

 the pointed pieces are rounded and grooved impressions, probably pro- 

 duced by the pressure of the arms (?) No surface markings are found 

 on the specimen, which has evidently lost its dermal covering ; they 

 would have been lost had they existed upon it. 



