SUBKINGDOM ECHINODERMATA. 



CLASS CEINOIDEA. 

 OEDEK PALiEOCBINOIDEA. 

 FAMILY MELOCKIN IBM. 



DOLATOCRINUS MAGNIFICUS, n. Sp. 



Plate 1, Fig. 1, basal view of the calyx, injured in the middle 

 part; Fig. 2, view of the vault, part of which is broken 

 away and the sutures between the plates only 

 partly preserved; Fig. 3, lateral view, 

 with the six-armed ray in front and 

 showing height of vault. 



Calyx very large sub-hemispheroidal, broadly lobed in the radial 

 fields and slightly concave below. The radial field opposite the 

 azygous side is much larger, more prominent and more broadly 

 lobed than either of the others. The diameter of the specimen 

 illustrated is two and six-tenths inches and height one and two- 

 tenths inches. The dome is only moderately convex, the radial 

 areas being raised and the interradial areas depressed. Surface of 

 the plates of the calyx sculptured, the larger ones bearing a cen- 

 tral node. The radiating ridges do not connect from one plate to 

 another, as is usual in the ornamentation of crinoids, but a radi- 

 ating ridge may be directed toward the suture between two adjoin- 

 ing plates, instead of joining an end to that of a similar ridge on 

 a contiguous plate; and there are shorter and longer ridges and 

 nodes on the plates. The plates of a kind, however, are orna- 

 mented alike and on the whole the ornamentation is very pleasing. 



The column, in our specimen, is broken off by an irregular fract- 

 ure and part of the radial plates are injured. Enough is preserved, 

 however, to show that the column is very large and conceals the 

 basal plates that are deeply sunken in the interior of the calyx. 

 The columnar canal is slightly pentalobate. 



