Batockinites. 



BATOCRINID^ W. and Sp. 



MoNOCTLic. The lower brachials with well defined interbrachials between them 



FORMING AN IMPORTANT PART OP THE DORSAL CUP. RaDIALS IN CONTACT EXCEPT 

 AT THE POSTERIOR SIDE, WHERE THEY ARE SEPARATED BY A HEPTAGONAL ANAL PLATE, 

 WHICH IS FOLLOWED BY A SECOND ANAL BETWEEN TWO INTERBRACHIALS. 



Analysis of the Genera. 



I. 



VeNTEAL disk highly DIFEBKENTIATED : THE PLATES LAKGE AND 

 HEAVY, FORMING A RIGID LNTEGUMENT. ArMS NOT BRANCH- 

 ING BEYOND THE CALYX 



A. Arms biserial ; basals three. 



1. Anus at the end of a tube. 



a. Interbrachials separated from interambulacrals by 



an arch of brachials. 

 Calyx biturbinate. 



Arms short, equidistant; anal tube very- 

 long and central; respiratory pores 



twenty, well defined 



Arms long, paddle-shaped ; anal tube exeen- 

 trio; respiratory pores twenty . . • 

 Calyx conical, dorsal cup almost fiat, ventral 

 disk greatly predominating in height; 

 anal tube central ; respiratory pores 

 twenty 



b. Interbrachials connected with interambulacrals. 



Arms arranged in groups, the openings di- 

 rected upward ; anal tube large, central. 



Calyx pyriform io wheel-shaped ; arms 

 twenty ; respiratory pores not visible 



Calyx elongate, biturbinate or subovoid; 

 arms twelve to sixteen ; respiratory pores 

 ten 



c. Interbrachials in contact with interambulacrals at 



anal side only. 



Calyx wheel-shaped ; anal tube very large, 

 central ; arms short, single or paired ; re- 

 spiratory pores twenty 



46 



Batocrinus. 

 Eretmocrinus 



Alloprosallocrinus. 



Lobocrinus. 

 Macroerinus. 



EiitrocTioerinus. 



