12 Spong, 
XVII, SPONGLE. 
3. GEOLOGICAL DISTRIBUTION (13, 18, 21,26, 27, 41, 56). 
Precambrian . — Rauff (41). 
Lower Silurian. — WlNCHELL & SCIIUCHERT (56). 
Carboniferous. — Hinde (21). 
Pleistocene. — Lambe (27). 
General.— Hackee (18), Koken (26). 
4. Phylogeny and Classification (17, 18, 36, 43) t 
Haeckel (18) considers the Sponges as a separate phylum of the animal 
kingdom belonging to his group Diploblastica , and defines this phylum 
thus: “ Coelenterien mit Dermalporen, ohne Tentakeln, ohne Nessel- 
organe. Gruudform der Person Monaxon.” The only organ system 
which can he used for classificatory purposes is the skeleton. Although 
he acknowledges the possibility or even likelihood of a polyphylotic 
origin of the Horny Sponges in the text, they are, both in the ancestral 
tree and in the classificatory scheme, put down as a monophyletic group, 
and derived from askeletous Sponges. This is a grave error. Anybody 
acquainted with Chalinine and Horny Sponges must know that some at 
least of the Horny Sponges are closely related to, and ho doubt descended 
from, Chalinids. The establishment of special groups for the askeletous 
and for those Sponges which possess a skeleton composed of sand-grains, 
or other foreign bodies, is equally unnatural, and must also be condemned. 
Haeckel’s classificatory scheme is the following : — 
I. Class. — Malthospongi^e (without spicules): 1. Myxospongicc (with- 
out skeleton) ; 2. Psammospongice (with a skeleton composed of 
sand-grains or other foreign bodies) ; 3. Cornuspongice (with a 
skeleton composed of horny fibre). 
II. Class. — SiLiciSPONGiyE (with siliceous spicules) : 1. Monactinella 
(primary spicules monaxon) ; 2. Pollactinella (primary spicules 
irregular, branched, or polyaxon) ; 3. Tetractinella (primary 
spicules tetractin) ; 4. Hexactinella (primary spicules hexactin). 
III. Class. — Calcispongi^e (with calcareous spicules) : 1. Leucon- 
ella (without horny fibre) ; 2. Pharetrella (with horny fibres). 
These 9 groups Hasckel calls Legions, and within them he distinguishes 
19 orders. 
Minchin (36) proposes a new classification of the Asconidce. He 
divides them into the three geuera — Clathrina , Gray ; Leucosolenia , 
Bowerbank ; and Ascandra , Haeckel, to each of which an entirely new 
meaning is given [see below, Recorder (29).] 
The Recorder (29) upholds his name Ilomandra versus Ascandra t 
sensu Minciiin. 
F. E. Sciiulze (43) gives a systematic account of the Euplectellidce , in 
which the older arrangements are somewhat modified. 
5. Methods (5, 42,55). 
According to Weltner (55) the best way to demonstrate the flagel- 
lum of the collar-cell and its basal, interplasmatic extension (in Ephy- 
datia) is to tease out a fragment of the fresh Sponge in a solution of 
corrosive sublimate. 
