HOLASCELLA TARAXACUM. 
29 
is distinguished from it by the possession of discohexasters ; another, H. stellatus, 
by the possession of oxyhexasters (hemioxyhexasters) with strongly curved rays ; 
and a third, H. fibulatus, which also has sigm microscleres, by the absence of oxy- 
hexasters. The fourth, H. obesus, which appears to differ from H. edwardsii 
only by its thicker body-wall and by having hypodermal hexactines with some- 
what longer distal ray, seems to be more closely allied to it. But the material 
on which F. E. Schulze bases this species was very fragmentary and his descrip- 
tion of it is somewhat incomplete. Therefore quite apart from the absence of 
ring-sigms in H. obesus and their presence in H. edwardsii , I should hesitate 
pronouncing these sponges, found respectively off Enderbyland in the Antarctic 
and off Peru in the Pacific, as specifically identical. 
HOLASCELLA, gen . nov. 
Tubular Euplectellidae (Euplectellinae) with root-spicule bundles and 
(probably) without parietal apertures. The body-wall is supported by a net- 
work of stout hexactines, pentactines, or tetractines held together by slender 
comitals. To discohexasters or microdiscohexactines, other hexasters, micro- 
hexactine forms, and pentactine and tetractine derivates of these may be added. 
The hypodermals are hexactines with spiny distal ray. The root-spicules are 
long, smooth shafts (rhabds or the long radial rays of pentactine anchors, the 
distal ends of which have been lost) and monactines with oblique, backwardly 
directed spines and a distal tyle, from which arise similar spines, representing 
anchor-teeth. The morphological centre (axial cross) of these spicules is situ- 
ated in the terminal anchor-tyle. 
The collection contains two more or less complete specimens and four frag- 
ments, which belong to three species, all of which are new. 
Holascella taraxacum, sp. nov. 
Plate 21, figs. 1-13; Plate 22, figs. 1-41; Plate 23, figs. 1-3. 
One specimen, the upper end of which is missing, but which is otherwise 
fairly complete, and three fragments of this species were trawled in the Eastern 
Tropical Pacific at Station 4649, on 10 November, 1904; 5° 17' S., 85° 19.5' W.; 
depth 4086 m. (2235 f.); they grew on a bottom of fine, sticky, gray mud; the 
bottom-temperature was 35.4°. 
The specific name refers to the similarity of the abundant discohexasters 
to the seed-balls of Taraxacum. 
