HEXACTINELLIDA. 
I. INTRODUCTION. 
In this Report the Hexactinellida collected during the Albatross cruises 
of 1899-1900 and 1904-1905 in the Tropical Pacific under the direction of 
Alexander Agassiz are described. 
Mr. Agassiz’s liberality has enabled me to employ methods of research and 
graphic representation not hitherto used and to describe the material very 
fully. 
II. METHODS. 
1. The soft parts. 
The deep-sea Hexactinellida which come into the hands of specialists are 
generally in such a condition that very little can be made out, by the ordinary 
methods of sectioning and staining, of their very tender soft parts. This is 
due to their mixing with the deep-sea ooze during the passage of the dredge 
over the bottom and to the pull and pressure acting on them in the long haul 
to the surface. After many experiments I finally found the following method 
best suited to this kind of material : — a piece of the specimen, 5 to 1 cm. in 
diameter, with intact surface is imbedded in paraffin and cut into thick radial 
sections. These are not stuck on the slide but placed free, first in xylol, then in 
alcohol, where much of the deep-sea ooze, which has got into the sponge during 
capture, and many of the fragments of spicules splintered in cutting fall out of 
the section, so that it becomes fairly clean. These loose sections are then 
