20 
rather abruptly in fine „canaliculi” the terminations of which are 
the eiliated chambres. From here the water comes into the excur- 
rent canaliculi, which assemble together, form „trabecular tubes’’ 
and end as a system of wider canals in the excurrent chones. The 
walls of the greater canals show particular complexes of fibres, 
„rugae”. Now I must begin to say that I am advanced by no 
means so far as Sollas. In /sops pallida f. i. I could not detect 
ciliated chambres; the small pieces that where at my disposal, and 
the state of preservation may be the reason, but nevertheless it 
seems to me remarkable. On the other side I saw very often that the 
Sponge-body shows a particular trabecular network. I have repre- 
sented a fragment in fig. 118 (pl. IV). Between the transverse 
sections of the canals c are a great multitude of openings; an 
exact examination informs us that the whole mass in which the 
canals are imbedded, is formed by a kind of trabecular network, 
strengthened here and there by spicules. 
The „rugae” as Sollas describes, are also present in J. pallida 
and sphaeroides. 1 have figured on plate IV a part of the canal- 
wall of Synops. They consist of bundles of thin fibres. 
These fibres occur also on other places in the membrane which 
lines the canal, and besides these fibres there are different kinds 
of cells, some of which have long and thin pseudopodia, which 
are often in connection one with another. (Compare fig. 119, plate 
IV). The membranes which line the canals of the Sponge under 
description have about the same structure. 
8. Synops pyriformis '!) n. g.; n. sp. [Pl. III, figg. 52—63; 
pl. IV, figg. 119 and 154]. 
Diagnos. Corpus pyriforme, cum radieium exordüs in limo haerens. 
Oscula in apice excavato congregata. Spicula indicantia : 
ac? (duo vel tria genera) | tr. | M. ta. @=V0° |M. ta. 
®>%° |M. ta. @<90° | st. | st. gl. | gl. | 
1) siv and rs; the oscula, with their walls, being congregated at the top 
of the Sponge. Compare the addenda. 
