60 
THE VOYAGE OF H.M.S. CHALLENGER. 
cirriferum ; the consistency of the body is rather loose ; there is no trace of any 
marginal border ; there are more than twenty cirri about *2 mm. long. On the dorsal 
surface is a longitudinal elevation crossed by furrows ; from this seven pairs of wavy 
lateral elevations are given off, which radiate outwards to the periphery. The most anterior 
pair of these is the smallest, and is. parallel with the middle one ; the others increase in 
breadth and height towards the margin of the body, where they terminate abruptly. 
The parapodia are slight ; there was no trace of any suckers. The mouth is 
subterminal, as also apparently the cloaca, if I am right in what I take to be the cloaca. 
The Martinique specimen is about half asdarge ; the circular contour of the body is more 
apparent, as it is not bent inwards ; the dorsal elevations are less, distinct ; this specimen 
was worse preserved than the first. 
Hosts. — (a) Actinometra pulchella, Pourt., sp., Station 193. (Martinique) of the 
“ Blake ” Expedition. 
(6) Antedon impinnata,. P. H. C., Mauritius, N. Bay* 15 fathoms; Kiel 
Museum. 
58. Myzostoma coronatum , n. sp. (PI. III. fig. 9, A, B, C ). 
This species is well marked by its characteristic shape and bright ochre-yellow colour. 
The largest of the four specimens examined is 3 ’2 mm: long and 2*2 mm. broad. The 
hinder portion is more obtuse than the fore part ; the contour of the animal is oval. The 
back is much vaulted, but less so in the anterior part of the body, especially from the 
level of the second pair of cirri, so that it appears to be transversely furrowed when 
viewed from above and behind. Towards the margin the body becomes thinner and 
flatter, and ends in ten pairs of broad cirri, the length of which is about *5 mm.; they 
are divided into a basal and distal portion of equal length. The dorsal surface is divided 
by longitudinal and transverse furrows into a number of quadrilateral elevations. In 
two specimens as large as that figured, the sides were bent down towards the ventral side ; 
the dorsal elevations were not flat but tubercular, and further removed from each other. 
The smallest specimen is nearly circular (1’2 mm. long, 1 mm. broad), and is sculptured 
on the back like the individual first described, but the furrows are rather shallower, and 
hence the elevations less distinct. 
The ventral surface ( A and B) has a large longitudinal ridge instead of the typical 
central elevation ; it commences at the subterminal mouth, and extends as far as the 
cloacal papilla, which projects a little beyond the margin of the body and may be 
seen from above. The large pharynx (ph.) was visible extending out of the mouth, and 
has behind its free margin a circle of papillae. Since these are visible from above they 
appear like a serrated circlet on the anterior portion. The ventral side is covered by 
delicate transverse furrows. The parapodia (p.) are placed very far outwards, and are 
