1886.] POSITION AND CLASSIFICATION OF SPONGES. 589 
1. Subfamilia Spongeline, Lendenfeld. 
Without flesh-spicules. The skeleton consists of distinct horny 
fibre containing a varying amount of foreign matter. 
Spongelia, Nardo; Dysidea, Johnston; and Reteplax, Lenden- 
feld, MS. 
2. Subfamilia Psammine, nov. 
The skeleton consists of foreign bodies cemented by spongin, 
which, however, is not distinctly visible; without flesh-spicules. 
Psammapemma, Marshall; Psammella, Lendenfeld, MS.; and 
Holopsamma, Carter. 
3. Subfamilia Spongelissine, Lendenfeld. 
The skeleton is composed of distinct horny fibres containing 
foreign bodies. With flesh-spicules. 
Dysideissa, Lendenfeld, MS. 
4. Subfamilia Psammopessine, nov. 
The skeleton consists of cemented foreign bodies without distinct 
horny fibres. With flesh-spicules. 
Psammopessa, Lendenfeld, MS.; Phoriospongia, Marshall; and 
Haastia, Lendenfeld, MS. 
5. Familia ApLysiLLip#,. Lendenfeld. 
The skeleton consists of spongin-tubes ramified in a dendritic 
fashion and filled with pith. 
1. Subfamilia Aplysilline, Lendenfeld. 
Cells are found in the pith of the fibres only. 
Darwinella, Fritz Miller ; Aplysilla, F. E. Schulze ; Verongia, 
Bowerbank ; and Dendrilla, Lendenfeld. 
2. Subfamilia Ianthelline, nov. 
Cells are found in the spongin-sheath of the fibre. 
Tanthella, Gray. 
6. Familia Hauisarcipa, Vosmaer. 
Without skeleton. 
Halisarca, Schmidt, and Bajalus, Lendenfeld. 
V. Key To THe Recent FaAMI.ies OF SPONGES. 
0. Skeleton calcareOus ....5.ccxccessensisexsesossessees ilF 
* [No calcareous skeleton .........0.000ssessceoeesseree (2.) 
Entoderm consists exclusively of collar-cells ... 3. 
1. 4 Entoderm consists of collar- and pavement- 
Ae CELIA Foeaedomocnescana deve. stueaeseesmerdeeseneesca ss (4.) 
Mesoderm thin, gastral cavity irregular ...... 1, Ascontdae. 
3. 4 Mesoderm thin, radial cylindrical chambers... 2, Homodermide. 
Mesoderm thick, irregular chambers ............ 3. Leucopside. 
