27 



BATOCRINUS SERRATUS, 11. Sp. 



Plate I, Fig. 28, basal view; Fig. 29, azygous side vieic; Fig. 



30, summit view. 



Species medium or below medium size, the one illustrated is 

 the largest among four which are before us. Calyx nearly 

 fiat; height one-fifth or one-sixth the diameter, and ambulacral 

 openings directed horizontally; radial series project at the 

 margin .so as to notch the circumference at the interradial 

 parts, and they are somewhat lobed, without radial ridges; 

 surface granular. Column round, medium size. 



Basa^ls form a subhexagonal disc, that projects below the 

 first primary radials about the thickness of a plate, has a 

 diameter about one half greater than the diameter of the col- 

 umn, and bears a slight concave, radiately lined depression, 

 for the columnar attachment. First primary radials twice as 

 wide as long, three hexagonal, two heptagonal. Second pri- 

 mary radials quadrangular and from two to three times as wide 

 as long. Third primary radials a little larger than the second, 

 twice as wide as long, pentagonal, axillary and in each lateral 

 ray support ujion each upper sloping side two secondary ra- 

 dials, the last of which is axillary and supports upon each 

 upper sloping side two tertiary radials, which gives to each 

 of these rays four arms. Upon the distal side of the third 

 primary radials adjoining the azygous area there are three 

 secondary radials, and on the jiroximal side, two secondary 

 radials, the last of which are axillary and bear upon 

 each svxperior slojiing side two tertiary radials which gives to 

 each of these rays three arms. In the ray opposite the azy- 

 gous area there are three secondary radials ujion each side of 

 the third primary radial, which gives to this ray two arms. 

 There are, therefore, sixteen ambulacral openings to the vault 

 in this species. 



The regular interradial areas are elongated and not uniform. 

 In two of the areas one large plate is followed by one short 

 small plate and one elongated plate that unites with two plates 

 belonging to the vault. In another area there are two plates 

 corresponding to the elongated plate just mentioned, and the 

 last one unites with the plates of the vault, and in the other 

 area there arc only two i)lates, one following the otlier, and they 

 are cut off by the third radials from uniting with the plates of 



