18 



ery and study has offered, not only that the forty-two species of 

 Agaricocrinus were confined to the geological ages, from which they 

 have been described, but that the genus and the entire family of 

 genera to which it belonged, so far as the biological part or the phy- 

 siological functions of the animals are concerned, were annihilated 

 absolutely from the face of the earth, in the Subcarboniferous pe- 

 riod of geological time. They were not annihilated at the same time 

 nor by any convulsion of nature. Instead of one species graduat- 

 ing into another, by improvement or decline, which may possibly 

 have been the case, in some instances of which we have no proof, the 

 general rule was that one species became extinct at one time and 

 place, and another became extinct at another time and at another 

 place, and, in this way, not only the forty-two species which are now 

 known were obliterated, but all the unknown species belonging to 

 the genus, and all allied genera which belonged to the same family 

 were annihilated before the Coal Measures or Carboniferous period. 



BATOCEINUS SHARONENS1S. 11. sp. 



Plate I, Fig. 7. azygous side view; Fig. 8, opposite view; Fig, !>. 



lateral view. 



Species medium size, somewhat biturbinate. Calyx funnel shaped, 

 rapidly expanded at the arms, a little less than twice as wide as high. 

 No radial ridges, surface plane and smooth or, possibly, finely gran- 

 ular. Ambulacral openings directed a little above a horizontal line, 

 and not visible in a basal view. An ovarian pore on each side of the 

 pair of arms opposite to the azygous area, and they are all we have 

 detected in two finely preserved specimens. 



Basals form a disc about four times as wide as high. It bears a 

 slight band and has an hemisperical depression for the attachment of 

 the column. First primary radials large and wider than long, three 

 hexagonal, two heptagonal. Second and third primary radials together 

 smaller than the first. Second primary radials quadrangular, two or 

 three times as wide as long. Third primary radials very little larger 

 than the second, pentagonal, axillary, and in the ray oj)posite the azy- 

 gous area bears upon each upper sloping side three secondary radials, 

 which gives to this ray two arms. In each of the lateral rays the 

 third primary radial bears upon each upper sloping side two sec- 

 ondary radials, the last ones being axillary, and bearing upon each 

 upper sloping side two tertiary radials, which gives to each of these 



