,A PORIFERA. I. 



spicules, developmental forms, ma>- be found; but it is, on account of the varying of the spicules as 

 to length and thickness, not always possible with certainty to determine the boundary between deve- 

 lopmental forms and fulh' develoiDcd oxea. 



In an individual of this species, from Egedesminde, were found a rather great number of a 

 little Amphipod [Aristias tumid us Kr.) sitting in the oscular papillae and most frequently at the \ery 

 point, projecting with half their bodies through the oscular opening. 



Locality: Djupivogur at the eastern coast of Iceland, depth 8 fathoms (H. Jonsson); Seydisfjord, 

 depth ca. 30 fathoms (A. C. Johansen); Stykkisholm, depth 20 — 30 fathoms (H. Jonsson); the Davis Strait, 

 depth 100 fathoms (Holm); Julianehaab, depth 24 fathoms (A. Jessen); Holstensborg (Traustedt) ; Egedes- 

 minde, depth 70 — 90 fathoms; Umanak, depth 50 fathoms (Moldrup, director of the colony), about 18 

 specimens in all. 



Gcogr. distr. West-Greenland ( Ingegerd and Gladau , Fristedt I.e.); Gulf of St. Lawrence 

 and the south coast of Nova Scotia, in some places on depths of ca. 48 fathoms (Lambe I.e.); Pitlekai 

 in the Tschuktsch peninsula; the Bering Sea 65" 10' Lat. N., 169'^ 50' Long. W., depth 25 fathoms (Fri- 

 stedt 1. c). When the localities from which I have had the species, are included, it is seen to be 

 spread from ca. 10 to ca. 180° Long. W., and it proves to be a northern species, as most of the 

 localities are found north of about 64° Lat. N. ; about here the southern boundary might be put; but 

 at the eastern coast of America it goes down to ca. 40' 30' Lat. N. ; that it is here found so far south- 

 ward, I take to be due to the Polar current, which just at this place runs down to the south of Nova 

 Scotia. With regard to the bathymetrical distribution it has been taken on depths from 8 — 100 

 fathoms. 



Of the genus Euiuastia only two species have hitherto been described, viz. besides the present 

 species Euiuastia sclimidtii Dendy (Proceed, of the Roy. Soc. Victoria VII, 1895, 240) from Victoria. 

 According to the descriptions it seems to be very nearly allied to E. sitiens, from which it is disting- 

 uished by having smaller spicules, only o-4™'° long, and by the surface being provided with projecting 

 spicules. — The genus is very nearly allied to Halic/ioiidria, and is chiefly distinguished from this 

 genus only by the papillae. Schmidt had also some misgivings with regard to the establishing of the 

 genus, and he says that an examination of a greater material might possibly show it to be identical 

 with Halichondria (Pellina Schmidt). This conjecture, however, has not been borne out by the facts, 

 and as now, moreover, one more species of the genus is known, it seems, at all events from a practical 

 point of view, at present to be better to keep it. The species of Halichondria, to which Euiuastia is 

 most nearly allied, seems to be the H. osculum described abo\'e. 



Reniera Nardo. 



T/ic form may br very luucli varying; fJ/c typical form is crust- or cushiou-sliapcd and provided 

 with more or fewer, higher or lozver oscular tubes; but the species may also be tubular, leaf-shaped, or 

 quite irregular. The skeleton consists of a more or less regular, most frequently rectangular, sometimes 

 triangular network. The fibres are typically unispicular, but may also often have a thickness of several 

 spicules, so that the primary ones are polyspicnlar, the secondary ones unispicular. or they may all be 



