MR. H. N. MOSELEY ON THE STRUCTURE OF THE STYLASTERIDEE. 
427 
got the animals to expand themselves so as to raise themselves above the level ol the 
stellate openings. Nevertheless he saw clearly with lenses the tips of the opaque 
white tentacles in the angles between the so-called incomplete septa, which tips were 
usually more or less bent inwards towards the centre. He also saw deep down in the 
bottom of the calicle a similarly opaque white knot-shaped projection. This was all 
that could be seen in the fresh living animals. Specimens were, however, preserved in 
spirit and subsequently examined, and the conclusion was come to that the animal was 
essentially different from the rest of corals, and probably did not belong at all to the 
Anthozoa, but rather to the Hydrozoa. 
By means of lucky breakings through of the stony-hard but nevertheless porous 
coral, Sars was able to obtain some little view of the general form of the polyps, and 
their relation to the coral. The true polyp body, he says, lies at the bottom of the 
central cavity of the calicle. It is very small, almost hemispherical in form, and 
provided with an apparently protusible beak or proboscis, which is sharply defined 
and blunt-conical in form, and on which no mouth opening was observable. At the 
circumference of .the head of the polyp proceed out the narrowly cylindrical tentacles 
which correspond in number to the in-foldings of the calicle. Their lower region is 
inserted in the interseptal canals, while their upper parts project free from the foldings 
in between the so-called septa, and usually bend with their bluntly rounded ends 
towards the centre. No distinct connexion between the different polyp cavities was 
to be observed. They all seemed completely closed below. But it is to be remarked 
that the whole upper lining part of the coral is highly porous. Often there were to 
be found outside real polyp cavities in the inner mass of the coral near the surface ; 
small cavities apparently everywhere closed, wherein were included one or several 
spherical bodies (eggs ?). Portions of the coral were decalcified in acetic acid. The 
organic basis remaining preserved to a considerable extent the form of the coral, and 
was composed of a tolerably regular network of apparently fibrous tissue in which 
were embedded numerous small elliptical nematocysts. The body of the polyp could 
be prepared out with considerable ease from this mass in connexion with its several 
tentacles, which under the microscope showed themselves beset all over with extremely 
small tightly packed nematocysts. 
Although Sabs thus suspected the affinity of the Stylasteridse to the Hydroida, 
his results were insufficient to demonstrate the fact, since he could obtain no satis- 
factory information concerning the generative structures of the coral which he studied, 
and he failed entirely to detect the compound nature of the cyclo-systems of Allopora, 
since he regarded the dactylozooids as the tentacles of the gastrozooid, or body of 
the polyp, as he terms it. He, however, determined a great deal which was of high 
value. He was the first to make any observations on the structure of the soft parts 
of the Stylasteridse, and is as yet the only naturalist who has watched a Stylasterid 
in the living condition. 
He concludes his account with the following words, which show that he was not 
