20 



constitute specific differences, though the two forms on cursory 

 examination are readily separated. If the arms were preserved 

 possibly the two forms could be specifically distinguished. 



D0LAT00KINU8 STELLIFER n. Sp. 



Plate II, Fig. 10, basal view; Ficj. 11, view of ihe vault, only part 

 of the sutures can be distinguished and the ornamenta- 

 tion is not preserved; Fig. 12, internal view of 

 the calyx showing the basal plates and 

 part of the first primary radials. 



Calyx low, basin shaped, three time as wide as high, deeply 

 and broadly concave below, the concavity extending to the middle 

 of the first interradials; columnar cavity deep; radial ridges quite 

 small. Surface of all the plates deeply, closely and radiately 

 sculptured. 



Basal plates extending in a cylindrical form up as high as the 

 top of the calyx and completely hidden externally by the column, 

 which fills the cylindrical area. The column is round and pierced 

 with a cinque-foil canal. First primary radials longer than wide 

 and together forming a funnel-shaped columnar cavity, ornamented 

 near the top with two raised lines, forming a pentagon, with a 

 furrow between them. Second primary radials a little wider than 

 high, quadrangular, gradually expanding upwanl, and each orna- 

 mented with a small, sharp radial ridge that rises at an angle 

 of the pentagonal ornamentation, on the first radial, and, crossing 

 the second and third radial bifurcates at the superior angle of the 

 third radial, from which point a bi-oken ridge crosses each second- 

 ary radial series to the free arms. Od each side of the radial 

 ridges the plates are closely, deeply and radiately sculptured. Tiiird 

 primary radials shorter than the second, pentagonal, expanding up- 

 ward to the lateral angles and supporting on each upper sloping 

 side a secondary radial series. 



There are four secondary radials in each of nine series, and they 

 become smaller toward the arms, which commence, at the arm 

 openings, with a double series of interlocking plates. They are 

 radiately sculptured from a more or less well defined central node. 

 One secondary radial series in our specimen consists of a single pen- 

 tagonal plate which bears upon each of the upper sloping sides a 

 tertiary radial series having three plates before reaching the double 



