86 
W. MICHAELSEN : 
Tartessus occidenlalis. n. sp. — Dirk Hartog. 
Deltocephalus arunda, n. sp. — Moora. 
Siphanta lucindae, Kirkaldy. — Karrakatta, Fremantle. 
Busas dissolutus, n. gen., n. sp. — Subiaco. 
Bunduic-a mbrovenosu, n. gen., n. sp. — Torbay. 
VOLUME II, Part 21. TETRAXONIDA, Part 1. 
By Dr. Ernst Hentschfl (Hamburg). 
Pp. 347-402, with Plates XXII and XXIII, and 29 figures 
in the text. 
In this first part the author treats those groups of sponges 
which are called according to the nomenclature of Dendy, Homo- 
sclerophora, Astro fib-ora and Astromonaxonellida, i.e., all those 
sponges which either have no true “ microsclerae,'' or which have 
only “ asters,” or which phylogenetically have been derived from 
sponges with “ asters.” These groups are treated in this part 
systematically. AH geographical reflexions and studies are 
reserved for the final part of the treatise. 
The author then gives a justification of the systematic 
views adopted in his paper, which differ somewhat from those of 
other authors. Joining the Astromonaxonellida of Dendy with 
the Astrophora of Sollas, and the Sigmatanionaxonellida of Dcncly 
with the Sigmatophora of Sollas, both groups having been derived 
from the Homosclerophora of Dendy, the author gets the three 
groups : — Homosclerophora , Dendy, A stroletraxomda, nov., and 
Signiatotetraxonida , nov. 1 he author on this system disregards 
the Ceralosa. This system of the Tetraxonida is in accord with the 
statement that in the order Tetraxonida the “ microsclerae ” are 
of first-rate systematic importance. 
Suborder HOMOSCLEROPHORA. 
Family OSCAREI.LIDAE. 
Oscarella membranacea, n. sp.— Sharks Bay (Surf Poin ). 
,, tenuis, n. sp.— Sharks Bay (S.W. of Denham). 
Suborder ASTROTETRAXONIDA. nov, 
Family PACH AST RE LLID AE . 
Dercitus occultus, n. sp. — Sharks Bay (Surf Point). 
Family STELLETTIDAE. 
Stelletta Tuberosa, n, sp, — Champion Bay near Geraldton 
,, purpurea Rich, var. grisea, n, var. - Sharks Bay (Middle 
Bluff, 
,, brevis, n. sp. — Sharks Bay (Surf Point). 
„ ,, var. Meet, n. var. — North Fremantle. 
„ „ var. pauper a, n. var.— Sharks Bay (Surf Point). 
