299, TRANS. OF THE ACAD. OF SCIENCE. 
interior of the calyx the base forms an elevated conical pro- 
tuberance 
The sub-radial pieces are thick and longitudinally recurved; 
four of them are pentagonal, a little longer than wide, their 
superior oat cies gently en and gsi pen gt than, the 
fideo late edges; the basal edges are very sh The 
fifth eibradial§ is gece em 7 superior angle being pe 
to su Cet an — ece: . 
mr et ded, The articular facet is very broad, pec 
zontal, and furnished with a prominent transverse | 
which is situated nearest the external margin. Exterior to 
this is a smaller ridge, which coalesces with the main one be- 
fore reaching the extremity of the pieces. Both ridges are 
‘strongly crenulated. ‘ 
_ Anal pieces.—Of these pieces only one remains in the speci- 
mens before us. It is rather small, clongatehexagol 
tian in between two of the first radials, above which it 
about half its yooh 
and ie are unknown. 
wine 
el ya jot fbasly velntad bi 
2 parewatas. We 
