REPORT ON THE MYZOSTOMIDA. 
31 
visible. The parapodia (p .) are proportionately small, but not so small as they are 
represented in fig. 30, and are placed in a circle occupying the middle of the body ; 
each parapodium has a basal portion and a smaller terminal portion. The suckers are 
placed a little to the outside of the parapodia. They are prominent and hemispherical in 
form and radially furrowed. The margin of the mouth (ph.) is prolonged beyond the sur- 
face of the body into a small tube equal in height to the suckers ; a number of papillae 
belonging to the pharynx project from its aperture. The large cloacal papilla (cl.) lies 
in the middle between the parapodia and the margin of the body. The latter is provided 
with probably twenty short tubercle-like cirri. 
Besides this specimen, collected during the Challenger Expedition, I have another in- 
dividual from the Copenhagen Museum, which is no doubt a younger stage of the same 
species. It is only 3 mm. long, of a uniform greyish-brown tint, with all the character- 
istic markings present though not so distinct. The rows of tubercles on the back are far 
smaller, and can only be seen by the help of a lens ; also they do not differ in colour and 
consistency from the rest of the skin of the back. 
Hosts. — (a) Probably Anteclon incisa, P. H. C., or Antedon incequalis, P. H. C., from 
Station 174 of Challenger Expedition (south-west of the Fiji Islands). 
(b) Actinometra mutcibilis, Liitken, MS., from the Copenhagen Museum. 
Dredged by Captain Andrea in 17 fatho ms ; lat. .23° 20' N., long. 
118° 30' E. 
6. Myzostomci cdcitum, Graff (PL I. figs. 25-29). 
Myzostoma cdatu.ru, Graft, Proc. Roy. Soc. Edin., vol. xii. p. 379. 
I have named this species from the character of the marginal part of the body, which 
is not unlike the “ wings ” of certain fruits, e.g., of the elm. This comparison is rendered 
more striking by the fact that the animal is longer than broad, and slightly notched at 
the middle of the anterior and posterior margins, Behind the anterior notch is a small 
cavity with five pairs of depressions ; this was caused by the presence of a young indi- 
vidual (fig. 25), which unfortunately was lost. Fig. 28 represents an ideal transverse 
section, and it may be seen that the central part of the body, strongly convex above, is 
much thicker than the marginal part, though the latter is not thin enough to be trans- 
parent, and there is no defined marginal border. The larger specimen is 3 mm. long, 
and the smaller 2 mm. The colour of the back is a dirty yellow, inclining to grey upon 
the ventral surface. The skin of the back is covered by numerous minute conical 
papillae, whereas the ventral surface is quite smooth. The parapodia are situated at the 
periphery of the central elevation (figs. 26, 27); they are extremely small, and consist 
merely of a circular fold, out of the middle of which projects the brownish-black tip of the 
hooks. The latter (fig. 29) are only '09 mm. long, and ‘013 mm. broad, but I am not 
confident of the accuracy of these measurements, since I did not remove the hooks 
