REPORT ON THE MYZOSTOMIDA. 
59 
intestine, which extends as far as the terminal thread, and a number of eggs ( ov . ) closely 
pressed together. The two anterior cirri (C.) arise just in front of the mouth, and are '4 
mm. long; the second pair are '12 mm., the last '2 mm. The intervals between the cirri 
are fairly regular, but somewhat larger than the rest is the interval between the caudal 
appendage and the last cirrus. The body is dark brown coloured (yellower in some speci- 
mens), and much more massive than in Myzostoma cirrferum; at the same time it is 
brittle. Towards the outer margin it is more transparent; the elliptical suckers (s.), remark- 
able by their large size (T8 mm. greatest diameter), are closely approximated to the margin 
of the body. The parapodia ( p .) are strongly developed, and often extend considerably 
beyond the margin of the body when the hooks are protruded. Above the third parapo- 
dium is visible on either side an oval vesicula seminalis, opening by the somewhat incon- 
spicuous male genital aperture ( $ ). 
The mouth is quite close to the anterior end of the body ; it is ventral in position, 
and followed by a large pharynx apparently provided with papillae (jph .). The cloacal 
aperture (cl.) opens on a conical papilla arising between the caudal appendages. 
Host. — Antedon hageni, Pourt., “ Corvin ” Expedition, May 17, 1867 ; off Sanclkey. 
56. Myzostoma Jiliferum, n. sp. (PI. Y. fig. 1). 
The body of this species is opaque and dark brown in colour, becoming gradually 
lighter and more transparent upon the margin; there are twenty short, obtuse cirri, which 
arise from a larger basal portion. The form of the body is nearly circular, and '7 5 mm. in 
diameter ; it terminates behind in two long caudal appendages, measuring more than 1'5 
mm. ; each of these is divided into a basal portion '24 mm. long, which contains an 
intestinal csecum and a fine terminal thread measuring 1 *35 mm. The length of this 
terminal thread and the dimensions of the cirri mark out this species as distinct from 
Myzostoma bicaudatum, which it otherwise very closely resembles. The first and the last 
pair of cirri in the latter are relatively and absolutely larger than the corresponding cirri 
in Myzostoma Jiliferum, though the animal itself is smaller ; in Myzostoma Jiliferum, in 
fact, these very cirri are the smallest ones of all. 
Host. — Antedon bidentata, P. H. C., Station 186 (Torres Strait) of the Challenger 
Expedition. 
57. Myzostoma carinatum, n. sp. (PI. II. fig. 9, A, B). 
I was able to examine only two not very well-preserved specimens— one from 
Martinique, the other from Mauritius. The following description relates to the 
latter, wdiich is shown in the figure (fig. 9). The colour of the animal is lightish 
yellow, its length 1'8 mm. ; it is somewhat cup-shaped on the ventral side. The thick- 
ness of the body is even, and is about the same as in a large specimen of Myzostoma 
