R. W. H. ROW—REPORT ON THE SPONGES : NON-CALCAREA. 287 
Reports on the Marine Bionoay of the Supansss RED SEA, from Collec- 
tions made by Cyrin Crossianp, M.A., B.Sc., F.Z.8. (Communicated, 
with an Introduction, by Prof. W. A. Herpman, D.Sc., F.R.S., F.L.S.) 
—XIX. Report on the Spoyeus collected by Mr. Cyri Crossnanp in 
1904-5. Part II. Non-Catcarza. By R. W. Harotp Row, B.Sc., 
F.L.S. From the Zoological Laboratory, King’s College, London. 
(PLates 35-41 and 26 Text-figures.) 
[Read 15th December, 1910.] 
INTRODUCTION. 
Tnx present report deals with 77 species and varieties, belonging to 44 genera, 
of Non-Calcareous Sponges, and is the second (and concluding) part of the 
report on the Red Sea sponges collected by Mr. Crossland in the years 
1904-5. The TriAxonipa are not represented in the collection, doubtless 
because the specimens were obtained entirely from coastal waters, and not 
from the deeper parts of the Red Sea, where Hexactinellid sponges are 
known to occur, Schulze having described three species from this region. 
The other orders of the Nox-Catcarza are all represented in the following 
proportion :— 
MyxosponeGipa, 2 species. 
TerraxonipA, 49 species, of which 24 are new, including 2 new genera. 
Hucrratosa, 26 species, of which 7 are new, including 2 new genera. 
The classification adopted in this report is based upon that of Prof. Dendy 
(11), in which the Non-Catcarua are divided into 4 orders of equal 
importance, viz., Myxosponcipa, TRIAXONIDA, TETRAXONIDA, and Hucera- 
TOSA, the last three groups, which differ from each other in the type of their 
skeleton, being each derived separately from the askeletous Myxosponeipa. 
In classifying the Tetraxonida, Prof. Dendy recognises 3 ‘“ Grades,” 
TETRACTINELLIDA, MonaxoneLiipa, and Lirxistipa. These groups are not 
considered to be necessarily monophyletic in origin, but he looks upon them 
as conyenient divisions for classificatory purposes, owing to the very easily 
recognisable characters by which they are distinguished from each other. 
He then further divides his grades as follows :— 
Order TETRAXONIDA. 
A. Grade Tetractinellida. 
Sub-Order 1. HomoscLeRopHoRa. 
2, ASTROPHORA. 
35 3. SIGMATOPHORA. 
LINN. JOURN.—ZOOLOGY, VOL. XXXI. 24 
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