12 Spong. 
XVII. SPONGEE. 
(ii) Relations of Sponges. 
Relations of Sponges to Protozoa; Jordan & Heath (24) pp. 19-21, 
27 & 28). —The “ spongocaele,” lined by ectoderm , is clearly not homologous 
with the “ gastroccele,” hollowed out in the endoderrn, of other animals; 
it is a question whether the Sponges and the “Monostomes” are descended 
from a common stock, or from separate groups of Protozoa. Sponges are 
to be regarded as descended from the Choanoflagellata, and the paren- 
chymula larva is directly comparable to Protospongia [= Proterospongia ] 
hceckeli. The analogy of the parenchymula with the planula is, however, 
evident, and the Monostomes might be regarded as derived also from 
Protospongia by the hollowing out of a cavity in the endoderm. In any 
case, “ Sponges ought to be separated radically from veritable animals, 
but it is probable that they form part of the same kingdom;” Lameere 
(30). —Position of Sponges in the Animal Kingdom discussed; Minchix 
(42) p. 812. —Sponges derived from an Accelous Turbellarian ancestor, 
which left the land and became adapted to sessile marine life; Simroth (57) 
pp. 156-158. 
Sponges as a stem (Stamm) of the Radiata, the other stem being the 
Cnidaria; Goette (16). —Porifera placed under Metazoa as the first 
group of the Achorodata [sic], of equal value with Ccelenterata (Cnidaria), 
Ecliinodermata, Vermes, etc.; Haller (17) pp. 62-67. —Porifera as a 
“ Branch ” of the Animal Kingdom, distinct from Protozoa, Coelenterata, 
etc.; Jordan & Kellogg (25) p. 307. —Porifera as a separate phylum; 
Masterman (41). 
(iii) Phytogeny. 
Vacant. 
B. Morphology. 
(i) General Accounts . 
Haller (17) pp. 62-77, tigg. 74-89: Jordan & Heath (24) pp. 23-27: 
Minchin (42).—General account of sponge organisation; Goette (16).— 
Popular account of the Porifera; Herdman & Chadwick (19).—Structure 
of sponges in general, with figures of Calcolynthus primordialis and 
Prophysema primordiale , after Haeckel; Jordan & Kellogg (25) pp. 32- 
37.—Description of Bycandra [Grantin'] compressci as a type of the 
Porifera, and general account of the Calcarea; Masterman (41) pp. 103- 
110, figg. 37-41.—General morphology of sponges; Schneider (54) 
pp. 177-183, figg. 231-237.—Structure of Grantia as a type of the 
Porifera; Pratt (47) pp. 161-163. 
(ii) External Characters. 
(a) Orientation, Attachment. —On the orientation of the Cri- 
norhiza- form of the genera Cladorhiza , Axoniderma, and Chondrocladia. 
Ridley & Dendy considered the peripheral fringe of spiculo-fibrous fila¬ 
ments as directed downwards, like the ribs of an umbrella; a new species, 
to be named Cladorhiza jlos abyssi, shows that the orientation formerly 
accepted must be reversed, and that the fringe is in reality inclined up¬ 
wards, like an expanded corolla. The true lower surface bears a stalk of 
attachment in some forms, in others the base is conical; Topsent (61). 
