ON THE SHETLAND CRUSTACEA, TUNICATA, ETC. 329 
necting spicula expando-ternate; radii attenuated, very long, shafts 
very short. Skeleton—fasciculi and reticulations stout and polyspicu- 
lous; rete open and irregular; spicula subfusiformi-acerate, long and 
large. Interstitial membranes pellucid, furnished abundantly with small 
subfusiformi-acerate tension-spicula, and with numerous large and small 
attenuato-stellate retentive spicula. Gemmules membranous, aspiculous. 
Colour in the dried state light grey. Habitat. Shetland, 110 fathoms 
(Rev. A. M. Norman). Examined in the dried state.” 
To this description of Dr. Bowerbank I may add that the “ subfusi- 
formi-acerate tension-spicula” are incipiently and entirely spined, and 
are, moreover, very frequently furnished with a central umbo. 
Ecionemia compressa, Bow. Rare, in very deep water, Unst Haaf, in 1864 
and 1868. 
Genus Quasrztina*, Norman, n. g. 
Sponge consisting of a single clavate hollow body, widening upwards from 
the base, and rising at once from the surface of the stone to which it is at- 
tached, without any expanded basal mass. Skeleton beautifully reticulate, 
primary fasciculi ascending in parallel straight lines from the base, and in 
diverging radiating lines from a central mammeform projection at the 
summit of the sponge; secondary fasciculi at right angles to the primary 
ones. Spicula fusifornfi-acuate. 
Quasillina brevis (Bow.)= Polymastia brevis, Bow. Brit. Spongiade, vol. il. 
p. 64. Frequent on pebbles in from 40 to 170 fathoms. It is necessary 
to separate this species from the genus Polymastia; for whereas in the 
latter genus several (often very numerous) fistular cloace arise from an 
expanded basal mass, which is, in fact, the body of the sponge, in Quasil- 
lina the entire sponge consists of a single hollow cylinder, which widens 
from the base upwards, and is most expanded near the summit. When 
compressed, a rupture always takes place between the summit of the 
column and the cap-formed top, which separates as a kind of lid. This 
lid, with its central mammeeform point, its radiating primary lines of 
bundles of spicules, and its transverse secondary lines, reminds us 
strongly of the top of a basket. In all these respects the genus ap- 
proaches very closely to the genus Huplectella, much more so than do 
the species of the genus Polymastia. The spicula are needle-shaped 
(acuate), swollen in the central part, and attenuated towards the ‘“ head” 
as well as towards the point; but they are not “‘acerate” as described 
by Dr. Bowerbank, the head end being blunt and rounded. The smaller 
spicules sometimes assume a slightly pin-shaped (“ spinulate”’) form. 
ie bulbosa, Bow. The type specimen. “Shetland, Mr. C. W. Peach, 
1864.” 
spinula, Bow. In 50-110 fathoms, on stones and shells. In a speci- 
men which has but one fistula, though its basal mass is only 7 of an 
inch in diameter, the fistula is no less than 14 inch long, but only 5}, of 
an inch wide. Other specimens have as many as five and six fistule. 
radiosa, Bow. The type-specimen. “Shetland, Mr. C. W. Peach” 
(Bowerbank). 
mammillaris (Miller). A single specimen in 1868, also procured by 
Mr. Barlee. 
Tethea cranium (Miller), Common on the Outer Haaf, sometimes attached 
* Quasillus, a little basket, 
1868, 24 
