OSCULA AND ANATOMY OF LEUCOSOLENIA CLATHRUS. 487 
had ever had oscula was that the anastomosing tubes converged 
towards the points where the oscula had been. 
These specimens, after being a few days in the aquarium, 
recovered slowly from their drooping condition, like a plant 
that has been transplanted. The tubes became rounded and 
of a healthy appearance, and sent out diverticula, which grew 
often to 10 or 12 mm. in length, and attached themselves to 
the side of the vessel. Such diverticula occur in the natural 
condition also (see fig. 2). From the places where oscula had 
been breast-shaped eminences raised themselves, which were 
normal closed oscula like fig. 3. Sometimes a small opening 
would appear in the “ nipple,” but only once did I observe in 
my aquarium that one of my specimens opened out a large 
normal osculum. Specimens with closed oscula like fig.3 are 
of frequent occurrence in nature, and I have often observed 
them in specimens fished up fresh on the steamer. I went on 
three separate occasions to the only locality where this sponge 
occurs abundantly in the Gulf of Naples—a very sheltered 
grotto near Capo Miseno,—and the following short erate of 
observations may be of interest : 
Oct. 2nd.—A fine bright day, the water smooth and clear. 
All the specimens had wide open oscula. 
Oct. 8th.—The weather as before. All the specimens had 
open oscula, and on this occasion I preserved fresh from the 
sea the colony from which figs. 1 and 2 aretaken. In one large 
specimen I observed a closed osculum. 
Oct. 19th.—The sea was smooth, but the day was cloudy, 
and the water in the grotto was turbid, so that when I dived it 
was difficult to see the sponges clearly under water. There 
had been scirocco and bad weather previously. Every speci- 
men examined had closed oscula. 
Since this date the weather has been so bad and the sea so 
rough that the steamer has been unable to put out, and somy 
observations are extremely incomplete ; but they give one at 
least the suspicion that the state of the sea and weather in- 
fluence the sponge, and cause it to contract or open: and, 
indeed, one can hardly wonder that it should be so. Leu- 
