SYSTEMATIC. 
Spong. 31 
D. DEMOSPONGIiE. 
(i) TETRAXONIDA. 
(a) Order CARNOSA. 
Dercitus plicatus (0. S.) Lend., perhaps includes D. simplex (Crtr.); Top- 
sent (59) pp. 343 & 344. 
Placina trilopha F. E. S., from Antarctic, described; Topsent (60) pp. 30 
& 31 and p. 7, pi. iii, fig. 1; Topsent (56) p. 4. 
Placortis simplex F. E. S., redescribed; Topsent (59) p. 344. 
(b) Order TETRACTINELLIDA. 
(1) Sub-order CHORISTIDA. 
Tribe SIGMATOPHORA. 
Family TETlLLlDfiE. 
Craniella cranium (Muller); Whiteaves (63) p. 12. 
Tribe ASTROPHORA. 
Family Theneida;. 
Tkenea muricata (Brok.); Whiteaves (63) p. 13. 
Family Pachastrellida:. 
Pachastrella monilifera 0. S., includes P. abyssi 0. S.; Topsent (59) 
p. 343. tP. primceva Z. should be given a new generic name; 
Schrammen (50) p. 18 footnote and p. 19. 
Family Stellettida:. 
Stolleya Schrm., remarks on the systematic position of the genus, p. 17 
footnote; +$. microtulipa Schrm. and t*S'. ornatissima Schrm., p. 19; 
Schrammen (50). 
t Tethyopsis steinmanni Z., p. 21 : its systematic position, p. 17 footnote; 
Schrammen (50). 
Family Geodida:. 
Cydonium gigas, ferments of; Cotte (13). 
Erylus discophorus (0. S.) Soil., from La Calle, Algeria, redescribed, 
pp. 338-341, pi. xiii, fig. 7, pi. xiv, fig. 2; E. euastrum (0. S.), its 
distinctness from E. stellifer , p. 342 ; E. stellifer Tops., redescribed, 
pp. 342 & 343, pi. xiii, fig. 1 : Topsent (59). 
Geodia canalicidata 0. S. vide Isops. t G. cretacea Schrm. ; Schrammen 
(50) p. 19. G. placenta 0. S., minute structure of the spicules [see 
ii, b, iv, b]; Butschli (9) pp. 236-271. 
hops canalicidata (0. S.), from La Calle, redescribed; Topsent (59) 
pp. 334-338, pi. xiv, fig. 5. 
