EEPOET ON THE MYZOSTOMIDA. 
53 
Host. — Probably Actinometra meridionalis, var. carinata, P. H. C., from Station 249 
(Grenada) of the “ Blake ” Expedition. 
43. Myzostomci oblongum, n. sp. (PL X. fig. 3). 
Of this elegant species I have but one specimen, which unfortunately is not well-pre- 
served ; but I have been able nevertheless to make out the characteristic features of the 
species. The body is delicate and oblong, 17 mm. long and 1 mm. broad; the two ends 
are obtusely rounded. The marginal border is broad (one-sixth of diameter), distinctly 
separated, and quite transparent ; it is provided with forty-four cirri (there were at any 
rate twenty-two upon one side, the other was not sufficiently well-preserved to make 
out their number); the cirri are ‘045-78 mm. in length, they are large, of equal 
diameter along their whole length, and terminate in an obtuse point. The suckers ( s .) lie 
within the marginal border ; they are rendered distinct by their darker colour and large 
size; they are hemispherical in shape and 7 4 mm. in breadth. The parapodia (p.) are 
feebly developed, and the pharynx {ph.) is small and retracted inwards. The mouth 
(w.) is ventral and situated in the middle of the marginal border; the cloacal aperture 
was invisible, owing to the hinder part of the body being filled with ripe eggs (ov.). 
Host. — Probably Actinometra meridionalis, var. carinata, P. H. C , from Station 249 
(Grenada) of the “ Blake ” Expedition. 
44. Myzostoma abundans, n. sp. (PI. X. fig. 1). 
This specimen is 3 mm. in length, and its greatest diameter 3 ‘2 mm.; it was dredged 
at Martinique. On examination with a lens and by transmitted light, the three regions 
into which the body is divided are very distinct ; the middle portion is yellowish-brown, 
and from its margin the relatively short parapodia (p.) arise. The strongly developed 
pharynx {ph.) is situated at the same level as the parapodia, the middle portion alone is 
somewhat thick — but thinner than in Myzostoma cirriferum — and 17 mm. broad; it is 
surrounded by a yellow zone, '45 mm. in diameter, which is occupied by the terminal 
ramifications (i.) of the intestine. On the inside of this lie the large oval suckers (s.). 
The marginal border is pale yellow, ‘3 mm. broad, and quite visible as a distinct region, 
even with the naked eye. There are nearly 100 short obtusely pointed cirri, which are 
more regular than those of Myzostoma caribbeanum; only a few are quite small, the 
majority being long and measuring ‘046-74 mm. Since none of the six specimens 
that I examined were absolutely intact, the number of cirri cannot be exactly stated ; a 
great many in the smaller individuals were broken off. The marginal border also and 
the intestinal zone, being extremely thin and delicate, were much injured. 
The mouth (m.) and cloacal aperture {cl.) are situated at the level of the external 
