LANUGONYCHIA FLABELLUM. 
Ill 
verse branches. Slender secondary end-rays 8-17 n long arise from the sides 
and ends of the primary end-rays and their terminal branches. The basal parts 
of these are directed obliquely backwards towards the centre of the spicule, but 
they at once curve strongly outward, their distal and middle-parts being fairly 
straight and directed obliquely outwards. Each of these secondary end-rays 
bears a terminal verticil of relatively large, recurved spines, which appears as a 
terminal disc with strongly serrated margin. These terminal spine-verticils, 
which measure as much as 10 n in transverse diameter, closely resemble the 
terminal spine- verticils of the discohexasters above described. In examining 
these remarkable spicules I gained the impression that their secondary end-rays, 
the basal parts of which are in exactly the same position relative to the primary 
end-rays as the spines, might be considered as hypertrophic spines. 
The amphiasters, which, as stated above, I believe to be foreign, have 
a shaft about 13 n long and 1.2 n thick, from each end of which arise three 
branch-rays, sometimes 23 n long. These branch-rays bear secondary branches 
at the end. 
The known species most closely allied to the sponge described above are 
Mellonympha velata (Wyv. Thoms.), Lanuginella pupa 0. Schm., and certain 
rossellinas. It differs from all these by its spiculation to such an extent, how- 
ever, that a new species must be established for it. About this there can be no 
doubt. It is more difficult to decide in which genus this species should be placed. 
Is it to be assigned to one of the already established genera and if so to which 
one, or is a new genus to be established for it? 
In regard to its internal microscleres and to its large pentactines Lanugony- 
chia flabellum resembles most closely Mellonympha velata, the only species of 
Mellonympha. Since, however, its body is lamellar and thin, since its dermal 
spicules are reduced hexactines, mostly with only from one to four fully developed 
rays, since it is very doubtful whether the large pentactines observed in it pro- 
trude beyond the surface to form a veil, and since ordinary small, not protruding 
hypodermal pentactines certainly occur in it, I hardly think it advisable to place 
it in the same genus as this ovoid sponge with its large, freely protruding velar 
hypodermal pentactines and its pentactine dermals. 
Lanuginella pupa, the only species of Lanuginella, although also differing 
from Lanugonychia very considerably in shape, resembles it more closely in 
regard to its dermal and gastral spicules. It is, however, destitute of onych- 
hexasters, spicules which are very abundant in Lanugonychia flabellum. Ijima 1 
1 1. Ijima. Studies on the Hexactinellida. IV. Journ. Coll. sci. Tokyo, 1904, 18, p. 12. 
