REPORT ON CORALS—HYDROCORALLIN &. 35 
MernHops EMPLOYED. 
The methods employed in investigating the structure of the Stylasteridee were mostly 
similar to those made use of in the case of Millepora. 
A brief examination of some of the soft structures of certain of the Stylasteride 
was made while they were in the fresh condition, and especially of the various ele- 
ments of Sporadopora dichotoma and of the female gonophores of Cryptohelia ; but 
since the trawl-net by which most of the specimens available for examination were 
obtained came up late in the day, very little, unfortunately, was able to be done in 
this way. 
Portions of the corals were preserved by means of chromic acid, osmic acid, absolute 
alcohol, and glycerine, and they were subsequently decalcified and examined in the 
usual manner by means of sections. In cutting the sections, a method described by 
Milchalkovies, Arch. fiir mikroskopische Anatomie, ul. Bd. 3‘* Hft., p. 386, was adopted 
and found to yield most successful results. The method is especially valuable for cutting 
fine sections of structures, the parts of which are loosely held together, and where it is 
desirable to maintain the exact relations in position of parts which in the sections other- 
wise become entirely disconnected from one another. A strong jelly composed of equal 
parts of glycerine and gelatine is used as an imbedding substance. It permeates the 
tissues and takes the place of the hard calcareous supporting structures which have been 
removed by the acid. The sections are mounted in glycerine, and the imbedding 
substance which is left zn situ in the sections becomes perfectly transparent ; in fact, 
almost invisible in this fluid. No doubt Dr von Koch’s method referred to above will 
yield valuable results in the future. 
STRUCTURE OF THE Harp AND Sort PARTS IN THE SEVERAL GENERA OF THE 
STYLASTERID. 
I now proceed to a detailed description of the structure of the several genera of the 
Stylasteridee. 
Each of the members of the family is composed of hard mert calcareous parts, or 
ccenosteum, and soft living structures. In the case of each genus the structure of the hard 
parts will be first treated of, and then that of the soft parts. The latter consists of 
coenosare, zooids, and gonophores, and will be described under these several headings in 
each case. A full description of all details will be given in the case of Sporadopora, 
which will be first accounted for, and in the cases of the other genera only those points 
in which they differ from it will be dwelt upon. 
