REPORT ON THE MYZOSTOMIDA. 
43 
The parapodia (fig. 5) are relatively feeble, and approximated to the flat margin of the 
ventral surface ; the strong flexure of the hooks (u.) and the manubrial plate (ma. ) is shown 
in fig. 4; the suckers, which I only saw in v. Willemoes Sulim’s preparation, are small, oval, 
and flat. The length of the ventral disk is 2 ‘3 mm., the breadth 1 '2 mm.; the mouth is 
subterminal, and the pharynx provided with a very long bulbus musculosus; the cloacal 
opening is terminal. 
Host. — Bathycrinus cddrichianus, Wyv. Thoms., from Station 146 (Prince Edward 
Island, Crozets) of the Challenger Expedition. 
25. Myzostoma brevicirrum, n. sp. (PI. VI. figs 3, 4). 
The largest of the six specimens which I had at my disposal was *5 mm. in diameter, 
and had the form of a transparent circular yellowish plate. The eggs were fully developed ; 
the spermatic vesicles and vasa deferentia were quite full of spermatozoa, showing that 
the individual was an adult. 
One of the specimens is brown, but this colour is probably due to the pigments of its 
host dissolved in the alcohol. The marginal border measures ’015 mm. across, and is pro- 
vided with short wart-like cirri, measuring about '01 mm. and situated at even distances. 
The alimentary canal is not remarkable ; the pharynx has a large bulbus musculosus, 
and is provided with papillae. The oral and cloacal apertures lie between the centre and 
margin of the body. The round suckers, '01 mm. in size, lie at the commencement of 
the exterior third of the radius. The strongly developed parapodia lie between the 
middle and border of the body. The hook- apparatus is feeble ; the hook is *09 mm. long 
(fig. 4, u.) and the manubrium (ma.) '07 mm. long, provided with a single end plate. 
Since in individuals of '24 mm. diameter the vasa deferentia and the seminal vesicles 
are filled with spermatozoa, whereas the eggs are but little developed, it may be concluded 
that the male apparatus is earlier developed than the female. 
Host. — Actinometra mutabilis, Lfitken, MS., from the Copenhagen Museum (No. I. 
from 23° 20' N., 118° 38' E. ; 17 fathoms ; No. III. from Tonga.). 
26. Myzostoma pictum, n. sp. (PI. II. fig. 22). 
The fine markings on the back of this species are sufficient to recognise it by, though 
the rollecl-up condition of the single specimen did not allow of any exact examination into 
the conditions of the ventral side. I am only able to state that the parapodia are but 
feebly developed, and are merely small stumps of ‘1 mm. in length, situated in slight 
depressions of the integument, and hardly recognisable even by the help of a lens. 
In the middle part the body is nearly as stout as in Myzostoma cirriferum, but becomes 
gradually thinner towards the marginal border, which is therefore not distinctly separated 
from the central part, although it contains none of the intestinal branches ; it is indeed 
semitransparent, but of the same consistency as other parts of the body. On the dorsal 
surface are three prominent pale yellow coloured longitudinal bands ; the median one is 
