VEGA-EXPEDITIONENS VETENSKAPLIGA ARBETEN. 411 
Il. Hexactinellid&e 0. 5. 
Genus Hyalonema Gray 
Hyalonema rosea n. sp. 
Plate 23, fig. 1—11, Plate 26, fig. 5. 
This new Hyalonema 18 represented by only three specimens, 
which are very fine and well preserved, all from the east coast 
of Greenland. All the specimens are round or rather ellipti- 
cal and compressed, the form slightly agreeing with that of a 
Polymastia Bow., the mamule naturally excepted. The three 
examples are almost of the same size, one a little larger, the 
greatest diameter 40 mm, the shortest not exceeding 25 mm. 
The height is tolerably constant, only 53 mm. The surface is 
even, but slightly hispid, the spicules being congregated in 
irregular bundles and projecting from the surface. The lower 
surface is a little concave. The distal margin obtusely at- 
tenuated. Oscula are minute, numerous, and dispersed. The 
consistency of the sponge like that of tolerably firm felt. 
Skeleton. The skeleton consists of large hexradiate 
spicules, only five of the rays being well developed; one of 
tbe rays is much longer than the others; of smaller hexradiate, 
all the rays being well developed; of rosettes of one kind: 
of slightly curved obtuse spicules with both the terminations 
microspined, and the spicule not rarely inflated at the middle; 
of very large acerate, sometimes spined along the points; of 
small, spined acerate spicules with four inflations at the middle, 
and finally of more rare spinulate spicules, the heads of which 
are microspined. 
The large obtuse spicules (Plate 23, fig. 3—4). These spicules 
are always more or less curved and armed with very minute 
spines at both the terminations. They are very numerous and 
often inflated at the middle. The length of such a spicule 
does not exceed 10 mm. 
The large acerate spicules (Plate 23, fig. 1). The spicules of 
this kind are the largest in this species. They are usually 
totally smooth, but sometimes slightly spined at the points. 
The central cavity is very large and seems to communicate 
