2 24 



NEW YORK STATE MUSEUM 



PLATE B 



1 6, 19 Extreme developments of ancistroid spicules with accessory- 

 hooks. 17 A liohexactin of normal style. 18 Like 17, with curved arms. 

 20 Hexactin with clavate arms. 21 Liohexactin with axis produced into a 

 rhabd. 22 Echinhexactin with spirally arranged thorns. 23 Liohexactin 

 with produced axial rhabd. 24 As 17 or 23. 25 Echinhexactin with very 

 sparse thorns. 26 Dumbbell spicule (monaxial ?). 



