24 AUT. 9. — I. IJIMA I HEXACTINELLTDA. 



much rent and flattened out. As the specimen is sealed up 

 between the glasses I have not undertaken a microscopic in- 

 vestigation of its spicules ; but in general structure it so closely 

 resembles Specimen A that I have little doubt of the two being 

 specifically identical. 



Spiculatiox. The following description of the spiculation 

 is principally based on my observations on Specimen A. It 

 may however be considered to hold good also lor Specimen B, 

 unless otherwise mentioned. Of each specimen I have four 

 microscopic preparations to make studies on. 



The regularly checker-like arrangement of the main skeletal 

 bundles in Specimen A made me at first assume the presence of 

 large stauractions among their elements. But in this I was 

 mistaken. For the principalia of the said bundles as well as of 

 the parenchyme in general, I have found only diactins. These 

 are long and bow-like or bent in the middle in an elbow-like 

 manner. The center is even-surfaced. The larger principalia in 

 the main bundles may be 15 mm. long and 150;« thick at the 

 center. 



The accessoria parenchymalia, occuring partly as comitalia 

 and partly in loose arrangement, are predominantly long and 

 filamentous diactins of the usual character. Length up to o mm. 

 or more. Breadth near the middle down to about 4 «. Center 

 four-knobbed, less frequently simply annulated. Occasionally the 

 four knobs are prolonged into regular rays, thus converting the 

 spicule into a hexactin in which one of the axes is more or less 

 elongated in excess over the others. Quite or nearly regular 

 hexactins of a medium or smaller size and with slender pointed 

 rays, are also not wanting among the accessoria parenchymalia. 



