10 



Family DOLATOCRINIDdv 



DOLATOCRINUS 1NDIANKNSIS, D, Sp. 



Plate HI, Fig. I, basal view; Fig. 2, summit view, azygous 

 side on Ihe left; Fig. 3, azygoiis side view. 



Species^ large. Calyx subhemispherical, very broiidly trun- 

 cated and slightly concave on the lower side, and constricted 

 below the arms. Very small radial ridges. Central nodes 

 small on the radial ridges and inconspicuous or obsolete on 

 the other plates. Radiating lines from the central part of each 

 plate numerous, but small. Column round and having a large 

 cinquefoil columnar canal that occupies more than half its 

 diameter. 



Basal plates form a pentagonal disc a little depressed below 

 the central part of the surrounding radials and having a 

 diameter about one third more than the diameter of the 

 column. First primary radials from one-third to one-half 

 widei- than long and subequal in size. Second primary radials 

 nearly twice as wide as long, quadrangular. Third primary 

 radials expand slightly to the superior lateral angles. They 

 are nearly twice as wide as long, pentagonal, axillary, and in 

 the rays on each side of the azygous area and in the ray op- 

 posite the azygous area bear upon each superior sloping side 

 a single secondary radial, which is axillary and bears upon 

 each upper sloping side a single tertiary radial, which gives 

 to each of these rays tour arms. In one of the lateral rays 

 the third primary radial hears upon one superior sloping side 

 two secondary radials and upon (lie other a single secondary 

 radial, which is axillary and bears upon each upper sloping 

 side a single tertiary radial. This ray. therefore, has three 

 arms. In the other lateral ray the third primary radial bears 

 upon each upper sloping side two secondary radials that give 

 to it two arms. There are, therefore, in this species seventeen 

 arms, and seventeen ambulacra] openings to the vault, all of 

 which are directed upward. 



The azygous area is like the other areas or so near like 

 them that it is hard to distinguish any difference. The first 

 interradials are the Largesl plates in the calyx, have nine sides, 

 and are broadly truncated above for the second interradials. 

 The second interradials are about, or less than, half as large as 

 the first, and are followed by a single plate less than half as 

 large as the second, and which unites with two elongated 

 plates belonging t<> the vault. 



