1886.] POSITION AND CLASSIFICATION OF SPONGES. 579 
II. Ordo HEXACTINELLIDA, O. Schmidt. 
Schulze (1369) divides the living Hexactinellida into the two 
Suborders Lyssacina and Dictyonina of Zittel. In the first, the 
spicules remain isolated or coalesce secondarily in an irregular 
manner ; in the second, the main spicules coalesce to begin with in 
a very regular manner, so as to form a continuous scaffolding. In 
the first suborder Lyssacina, the families Euplectellide, Gray, 
Asconematide, F. E. Schulze, Rossellide, F. E. Schulze, and 
Hyalonematidee, Gray, are placed. The second suborder, Dictyonina, 
comprises the families Farreide, Gray, Euretide, F. E. Schulze, 
Melittionide, Zittel, Coscinoporide, Zittel, and Meandrospongide, 
Zittel. To these the fossil families Ventriculitidee, Staurodermide, 
Callodictyonidze, Cceloptychide, Receptaculitide, and Monakidee 
must be added. 
In the classificatory scheme below, Schulze’s diagnoses are 
translated. 
III. Ordo CHONDROSPONGLA, Lendenfeld. 
As mentioned above, this Order coincides nearly with Vosmaer’s 
(1550) order Spiculispongie. I divide it into the two groups, 
Tetraxonia and Monaxonia. The former comprises the Sponges 
with tetraxon spicules, Tetractinellids and Lithistids ; and the latter 
those forms which haye monaxon spicules, or which have no spicules 
at all. 
Sollas (1453) divides the Tetraxonia into two groups :—Choristida, 
Sollas, without lithistid sclerites; and Lithistida, Zittel, with 
lithistid sclerites. In the first group the families Plakinide, 
Pachastrellide, Corticide, Tetillidee, Theneide, Stellettidee, and 
Geodine are distinguished. 
Vosmaer (1550) divides the Lithistidse, in accordance with Zittel 
(1639) and O. Schmidt (1306, 1322), into the families Rhizomori- 
nidew, Megamorinide, Anomacladinide, Tetracladinide. 
The Monaxonia comprise the families Suberitide, Spirastrellidee, 
Tethyde, and Chondroside. The Clavulina and portion of the 
Oligosilicina of Vosmaer. 
IV. Ordo CORNACUSPONGLE. 
I divide the Cornacuspongiz into the two suborders Halichondrina 
with, and Ceraospongize without, proper spicules in the supporting 
skeleton. 
The Halichondrina comprise the three families Homorhaphide, 
Heterorhaphide, and Desmacidonide of Ridley and Dendy (1265, 
1266). 
The Ceraospongie are divided by me into two groups—Macro- 
camerze with large, and Microcamere with small, ciliated chambers. 
To the former belong the families Aplysillidee and Spongelide, and 
to the latter the Spongidee, Aplysinide, and Hircinide. 
After this general view of the Classification of Sponges, I shall 
proceed to give a “system”? of Sponges down to subfamilies, 
mentioning the principal genera in each group. 
