350 SIR SIDNEY F. HAEMER ON 
alternate zooecium, the rostrum linear and directed obliquely inwards and 
distaliy. Frontal avicularium succeeding an ovicell gigantic, directed trans- 
versely outwards, the upcurved rostrum resting on the distal border of the 
ovicell, the much elongated linear mandible on the distal side. Marginal 
avicularia varying in size, usually small, the rostrum directed obliquely 
outwards, basally and proximally ; occasionally gigantic ; on the fertile zooecia 
gigantic, originating slightly on the basal side, the rostrum directed distaliy,. 
nearly parallel to the edge of the branch, the distal half free, the mandible 
on the outer side. Basal avicularia (one pair) occur on the inner zooecia 
succeeding the joints, inflated proximally, the long linear rostrum directed 
distaliy ; each giving off a rootlet at its proximal end, in line with itself, the 
rootlet running closely attached to the margin of the axil. Ovicells large and 
very long, imperforate except for a transversely elongated fenestra, on the 
frontal surface, near the orifice. 
'Siboga' Expedition, Stat. 211, 5° 40' 7" S., 12a° 45' 5" E., 1158 metres. 
Various species which have been referred to other genera appear to belong 
to Notoplites ; and, in some of these, basal avicularia have already been 
described or have been found by me in specimens in the British Museum 
Collection. In other species basal avicularia seem to be wanting ; but here, 
as in other genera of Scrupocellariidse, it may be assumed that an important 
generic character may fail to develop, the affinities of the species being 
indicated mainly by the mode of bifurcation. 
(a) S-pecies in which basal avicularia occur. 
2. Notoplites biloba {Busk). 
Cellularia biloba, Busk, 1884, p. 18, pi. 3. figs. 2-2 J. Azores, 900 fatlioms. 
Resembling iV^. rostratus in habit, in the form of its zooecia, scutum, 
marginal avicularia, and ovicells. Frontal avicularia wanting. The ' Chal- 
lenger ' slides (87.12.9.63j 64) show a pair of small transverse basal avicularia, 
which were not noticed by Busk, at the bifurcation. 
3. Notoplites crateriformis (Busk). 
Cellularia cratei-iformis Busk, 1884, p. 16, pi. 3. figs. 1-1 b. E. of Buenos Aires, 
1900-2650 fathoms. 
Resembling the preceding species in habit and in the marginal avicularia. 
Scutum and frontal avicularia wanting. Of the ' Challenger' slides (87.12.9. 
51, 52) .")1 shows a pair of small basal avicularia, directed nearly transversely, 
at a bifurcation. These seem to be referred to by Busk, who says : 
" Occasionally a radical tube may be seen supporting, instead of an ordinary 
zooecium, a small curiously formed avicularium." 
