VEGA-EXPEDITIONENS VETENSKAPLIGA ARBETEN. 307 
Thuiaria robusta, 5. F. Clarke. 
PE he tt EL fe 20 
This species, described by Clarke from Bering Strait and 
adjacent parts of the Arctic Ocean, occurs in the Vega col- 
lection from long. 119” E. 
It is a shorter, stouter and more bushy species than 
T. plumosa. The gonangia are quite different in shape: those 
of T. robusta being short and conical with long pointed horns, 
while those of T. plumosa are long and narrow, with the horns 
reduced to short processes. In this respect, and also in the 
narrower and more distincetly bilabiate hydrothece, and in 
general habit, T. plumosa verges towards T. (S.) cupressina, 
T. robusta similarly towards T. argentea. 
Thuiaria Vege&e, n. sp. 
Pl. 20, fig. 18, 20, 21, 22. 
Shoots slender, upright, tapering: branches close and numerous, 
somewhat spirally arranged, and leaving no bare region in the lower 
part of the stem: branches pinnate, directed upwards, and lying close 
to the stem; hydrothece subalternate, tubular, adherent for half their 
length or rather more, divergent above: aperture small, indistinctly 
bilabiate; gonothece broad above, tapering below, with a short sharp 
horn above at each side, and a central aperture raised, marginate, 
and with the margin encircled by small teeth. 
This apparently new form occurs from two stations, both 
of them shallow-water, viz. in long. 142? 36' and 144? 20' E. 
It is a small species, about 4 inches in height, but the 
hydrothec&e are exceptionally large, being not far from twice 
as big as those of T. (S.) cupressina. 
The closeness and upright growth of the branches give 
the zoophyte a bushy appearance. The subspiral arrangement, 
branching, and the form of both hydrothece and gonangia 
bring it into relation with the group to which TI. plumosa, and 
T. robusta belong, but it differs markedly from these in its 
distinetly pinnate branches. 
The hydrothec&e of all three species are slightly different 
one from another. Those of T. Vege are the largest, the most 
divergent above, the most bulging below, and the least di- 
stincetly bilabiate. In both T. plumosa and T. robusta, the hydro- 
thece are adjacent to the stem for nearly their whole length, 
