66 DR.J.S. BOWERBANK ON SILICEO-FIBROUS SPONGES, [Jan. 28, 
23. Mretampus Fascratus, Desh. 
From the same islands as the preceding. 
24. Mevampus Carrer, Kiist. 
From Mahé. 
25. MELAMPUS BRIDGESII, Carp. 
From Mahé. Under damp stones, close to the sea; extremely 
local, I only found it at one spot. 
26. PLECOTREMA, Nn. sp.? 
From Mahé. Under the stones of an old jetty at Port Victoria ; 
rare. 
27. NERITINA GAGATES, Récl. 
From Praslin. Ina very small rapid stream, close to where one 
crosses to go to Curieuse; very local. 
28. Mevanta (MELANorpEs) TuBERCULATA, Mill. 
From Mahé, Praslin, and Silhouette. 
29. Pyrazus PALusTRIS, Linn. 
From a creek at Mahé, near Port Victoria. 
30. Patupomus asanensis, Morl. 
From a rapid stream, rather high up, at Mahé; rarely collected. 
31. Patupomus, n. sp. ? 
From Silhouette. Very rare; in a small stream, very high up. 
3. A Monograph of the Siliceo-fibrous Sponges. 
By J. S. Bowersanng, LL.D., F.R.S., F.Z.S., &e.—Part I. 
(Plates IIL, IV.,.V.,:& Vis) 
In my observations on Dr. Gray’s ‘‘ Notes on the Arrangement 
of Sponges,” published in the ‘ Proceedings’ of this Society for 1868 
(pp. 124 & 125), I have stated my objection to his arrangement of 
the siliceo-fibrous sponges, several species of which he has named 
and described in the volumes of the ‘ Proceedings.’ His descriptions 
are very brief, and are mainly dependent on the characters of 
external form and the peculiarities of their surface; but although 
describing them as sponges, he appears to be still in a state of un- 
certainty regarding their real nature. In his descriptions of his 
genera MacAndrewia and Myliusia (Proc. Zool. Soc. 1859, p. 437), 
throughout the whole of the paper, he expresses doubts of their 
spongeous nature, and inclines to the belief, in p. 440, that they, 
with Dactylocalyx, might “all prove to be a peculiar family of 
