dredged up from Bass'' s Straits. 377 



to the absence of sarcode destroyed chieflj bj the presence of 

 sea-salt, to comparative firmness, with the dried sarcode still 

 left about them ; and it is from this numerous collection, 

 tog-ether with several belonging to the Liverpool Free Mu- 

 seum, which were dredged off Curtis Island, in Bass's Straits, 

 bj Capt. H. Cawne Warren, that the description above given 

 has been taken. Among the latter is one on the branches of 

 a specimen of Mopsea [Isis] encrinula, Milne-Edw., to which 

 I might add another from Algoa Bay on a specimen of Mopsea 

 gracilis^ Milne-Edw., sent me by my friend Dr. Dickie in 

 1873. 



The kind of arenaceous foreign material in Dysidea Kirhii 

 will of course depend upon that of the locality : viz. if only 

 arenaceous, it will be chiefly composed of sand-grains ; if 

 spiculiferous, of sponge-spicules and their fragments, &c. 

 But there is one element, viz. a little prism of calcite, generally 

 banded with brown, yellow, or red, singly or in conjunction, 

 that might puzzle the observer if it were not stated that this 

 comes from the disintegrated structure of very thin bivalve 

 shells like Pinna ; hence the prismatic form and banded colours. 



The ubiquitous parasite Spongiophaga communis also occa- 

 sionally infests Dysidea Kirkii. Again Oscillaria spongelicBj 

 Schulze, appears apparently as a commensal in Spongelia 

 pallescensj wherein Prof. Schulze has found it even in the 

 embryo, as his published accounts will show (Zeitschrift f. 

 "wiss. Zoologie, Bd. xxxii. Taf. v. fig. 7, &c.), and also 

 preparations which he kindly sent me. Marshall, too, repre- 

 sents an Oscillatorian in the " syncytium " of his Psammoclema 

 ramosum — Dysidea ramosa^ Hackel in sched. {^ib. Bd. xxxv. 

 p. Ill, Taf. vii. fig. 15). Spongiophaga communis ^ how- 

 ever, is a destroyer, and not a commensal. At what period 

 these parasites enter the sponge may be a matter for specula- 

 tion, but can hardly be one of certainty, as in Schulze's case 

 they were found in the embryo. 



All the specimens of Dysidea Kirhii that I have seen have 

 been dry ; but as Dysidea is one and the same with Spongelia^ 

 which Prof. Schulze has studied in the Adriatic while "fresh^ 

 I cannot do better than refer the student .to his paper for all 

 this part of the subject (Zeitschrift f. wiss. Zoologie, Bd. xxxii. 

 p. 117 &c. Taf. v.-vii. 1878). 



ECHINONEMATA. 



Dictyociilindrus reticulatus^ n. sp, 

 (Pi. XVIII. fig. 7, a-c.) 



Feathery, branched, tufted, stiff. Colour brown. Surface 



