41 



TAXOCRINUS WETHERBYI, U. Sp. 



Plate IV, Fig. o', basal view, azyr/ous side down; Fig. 4, view 



opposite the azygous side; Fig. 5, summit vieio of 



same specimen, having the ends of the 



arms obscured by ilie matrix. 



This species is founded upon two specimens presenting the same 

 general characters, shown by the illustrations, and while the first 

 impression may be, that they are compressed longitudinally, yet a 

 close examination does not reveal any displaced plates, and the 

 rugular infolding of the arms leads to the conclusion, that they 

 are very little, if any, out of their normal condition. That being 

 true, the calyx is very short and broadly expanded. The radial 

 ridges are rounded and the interradial areas flattened or depress- 

 ed, giving a pentagonal outline to the calyx as seen from below, 

 but a rounded outline when the infolded arms are seen from above. 

 The surface of the plates is finely granular and the sutures are 

 distinct. 



Basals covered by the column. Subradials very short and su- 

 perior angles obtuse. Primary radials four, in each ray, broadly 

 rounded and differing very little in size. The sutures are trans- 

 verse without any overlapping. The fourth plate in each ray is 

 axillary and supports upon each superior sloping side two second- 

 ary radials. The secondary radials are only a little smaller than 

 the primary. The second secondai-y radials are axillary and the 

 proximal sides, in each radial series, support two tertiary radials, 

 the last of which are axdlary and support a quaternary series of 

 plates above which rays again divide, the distal sides support four 

 tertiary radials the last of which are axillary and above which the 

 radial rays again divide. The above method of division is with- 

 out variation, in the specimen, illustrated, except in one iastance, 

 where a third tertiary radial is axillary instead of the second 

 plate. In the other specimen there are more bifurcations on the 

 third tertiary radial in the distal series than there are on the 

 fourth. If there are any more divisions than those mentioned, 

 they are covered by the matrix. By the divisions above men- 

 tioned there are fourteen arms to each ray or seventy arms in the 

 species, and the differences in the rays commence in the tertiary 

 radials, above which, radial differences are not of specific impor- 

 tance. 



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