14 S'pong. 
SPONGI.®. 
yellow filaments in the calcareous matter, supposed by Nassonow to be 
prolongations of the Sponge-body, are shown to be vegetable parasites, 
having no connection with the Sponge. The author then reviews and 
criticizes the hypotheses of earlier writers on this subject, arriving only 
at negative conclusions himself. 
The author further disousses the harmful effects of the Clionce on oyster 
culture, and how oysters may be protected against them. Since the 
Sponge only attacks oysters of more than two years growth, it is suggested 
that a sort of filter of old shells should be placed at the entrance of the 
tanks in which the oysters are placed to ripen in the months of Septem- 
ber and October, to attraot and arrest Sponge-embryos. Further, that 
the oysters should be examined frequently, and infected specimens 
plunged into fresh water to kill the Sponge, care being taken to make the 
oyster close its shell first. 
DISTRIBUTION 
IN SPACE AND TIME, 
See v. Dalla Torre, Dendy (1) (Chalinince), Gaudry, Giard, Hanitscii, 
Hinde, Pocta, Sovinsky ( Spongillidce ), Topsent (1), Topsent (2), 
Topsent (3), Topsent (4), Topsent (5) (Microsclerophora) , Topsent (G), 
Topsent (7), Weber ( Spongillidco ), Wiiitelegge, Zyicoff ( Spongil - 
lidce). 
METHODS OF PRESERVATION, INVESTIGATION, Etc. 
See Lo Bianco, pp. 445, et. seq., Ciiatin, p. 889, Maas, pp. 529-531, 
Noll, pp. 497 & 498, Vosmaer (1), 
SYSTEMATIC. 
I, OALCAREA. 
New species - 
Leucaltis impressa , n. sp., Hanitscii, pp. 234-236, pi. xv, fig. 3. 
Leucandra balearica , Lac., n. var, Linaresi , Giard, p. 71, footnote. 
Dendy (3) finds that Teichonella labyrinthioa , Carter, is a true ISycon , 
and terms it provisionally Grantia labyrinthioa , 
Giard finds that Ascandra variabilis is distinct from A. contorta , and 
riot identical, as Barrois supposed. 
II, IIEXACTINELLIDA. 
New species ?-r- 
Chonelasma schulzei , n. sp., Topsent (2) p. 70. 
Hexactinella grimaldii, n. sp., id. (2) p. 71. 
Periphragella lusitanica , n. sp., id. (2) p. 70. 
