572 Transactions of the Society. 



with disk-shaped depressions on them at least ^Air inch in dia- 

 meter. Sometimes the depression leads to a deep penetration into 

 or towards the axial canal, which has the same diameter of ^dVtt 

 inch. In one instance a spicule was crowded with them, and pre- 

 sented a very remarkable appearance, for the refraction of the 

 hollowed out and removed parts which are filled with Canada balsam, 

 difi'ers much from that of the siliceous spicule. One specimen 

 shows the appearance drawn by Mr. Carter; in another the 

 circular depression on the outside of the spicule leads to a globular 

 penetration without the intervention of a cylindrical portion. 

 The globular part has a greater diameter than the external circular 

 erosion. In many instances bodies resembling nuclei and granular 

 protoplasm, faintly green in tint, are observed in the penetrations 

 and in the axial canal.] 



