REPORT OR THE MYZOSTOMID A. 
47 
32. Myzostoma agassizii, n. sp. (PL VII. fig. l). 
The body is circular and extremely delicate, and transparent not only in the 
marginal border, but in the part which lies outside the parapodia and suckers, and contains 
the intestinal caeca. The margin is provided with twenty cirri, which are very long and 
drawn out into fine points, and show very distinctly a glutinous cell furrow. The longest 
cirrus of the individual shown in fig. 1 measures '57 mm., the diameter of its base being 
'06 mm. The last two pairs are the largest, and the interval between them is greater 
than that between the rest. In another specimen one of the lateral cirri measured '2 mm., 
the penultimate (and longest) '45 mm. 
I examined in all twenty-two specimens, which varied from '3 mm. to 1‘4 mm.; they 
were all light yellow to dark brown in colour ; the cirri of the smallest specimens were 
of equal length, measuring about '045 mm. and at an equal distance from each other ; 
the tenth pair of cirri become much longer than the lateral cirri in individuals of '6 mm. 
in length and upwards. 
The small size of the body and the fineness of the cirri give this species a pecu- 
liarly elegant appearance ; it no doubt moves in great part by undulations of the body, 
inasmuch as none of the specimens that I examined save the two smallest were without 
some bendings and foldings of the margin of the body. The parapodia (p.) are feeble, and 
situated nearer to the centre than to the margin ; the small oblong, indistinctly-marked 
suckers ( s .) are situated far inwards, in the region of the intestinal cseca. The mouth is 
ventral, and lies on a level with the terminations of the intestinal cseca, while the cloacal 
aperture is distant from the margin about twice as far as the mouth. The pharynx has 
a long bulbus musculosus (ph.). 
Hosts. — This species has at least two hosts, but only one can be mentioned with cer- 
tainty. 
(a) Antedon hageni, Pourt., dredged by “Bibb” Expedition near Bahia Honda, in 
100 fathoms, on May 4, 1868. Antedon hageni was also most probably the 
host at -Station 32 (August 1877) of the “ Blake” Expedition. 
(b) Myzostoma agassizii was also taken at Stations 155 and 269 of the “Blake” 
Expedition. Antedon hageni, however, occurred at neither of these Stations ; 
the species found in great number at both was Antedon spinifera, P. H. C. , 
which, therefore, is probably the host. 
33. Myzostoma dubium, Graff. 
Myzostoma dubium, Graff, Genus Myzostoma, p. 14, pi. ix. figs. 2-5, 
Hosts —-Antedon triquetra, Semper, MS., and Antedon dubia, Semper, MS., Bohol 
(Philippines). 
