PLATE XI. 
In all the Plates the following letters have the same signification. 
c. Marginal cirrus. 
cl. Cloacal papilla or opening. 
i. Intestine. 
in. Mouth. 
ma. Manubrium of the supporting stalk of the hook-apparatus. 
ov. Ovarium. 
p. Parapodium. 
ph. Pharynx. 
s. Sucker. 
t. Testicle. 
u. Hook of the hook-apparatus. 
$ Male genital papilla or opening. 
Note. — The coloured drawings show the object seven times magnified ; the uncoloured drawings are drawn with the 
Oberhauser camera and objective 0 (Seibert and Krafft), which magnifies 40 diameters, the hook-apparatus with camera and 
objective IV., which magnifies 220 diameters, if the contrary be not expressly stated. 
Figs. 1, 2. 
Fig. 3. 
Fig. 4. 
Fig. 5. 
Fig. 6. 
Fig. 7. 
Fig. 8. 
Fig. 9. 
Fig. 10. 
Fig. 11. 
Fig. 12. 
Fig. 13. 
Fig. 14. 
Fig. 15. 
Figs. 1-3. Myzostoma coriaceum, n. sp. 
The animal, seen from the ventral side. 
A diagrammatic cross section. 
Figs. 4-8. Myzostoma asymmetricum, n. sp. 
Portion of an arm of Pentacrinus alternicirrus, P. H. C., magnified. From 
the dorsal side (A), and from the side ( B ), in order to show the swelling 
of the arm and the two pinnules ( # ) enlarged by the Myzostoma. 
The same without the pinnules of one side, to show the base of an enlarged 
pinnule, which base bears the Myzostoma. 
This pinnule from the side ( B ), and in cross section (A), in order to show the 
groove where the Myzostoma lay in contact with it. 
The Myzostoma from the ventral side ; magnified about 28 diameters. In this 
figure the letters p and ph have been interchanged. 
Diagrammatic cross section through this Myzostoma. 
Figs. 9-15. Myzostoma pentacrini, hi. sp. 
Thickened portion of an arm of Pentacrinus alternicirrus, P. H. C. Seen 
from both sides (A, B ), and from the dorsal side (C). The arm-joints a-e 
participate in the swelling. In B the Myzostoma, lying in a cyst, can be 
seen through the aperture in the joint c. 
The arm divided in the direction of the arrow (fig. 9, C ), seen from the distal 
end. The two chambers, containing each a Myzostoma, are separated by a 
strong septum. 
The half of a squeezed preparation made by v. Willemoes Suhm to show the 
intestinal ramifications (i). 
The animal (fig. 9), seen from the dorsal side. 
The same, from the ventral side ; magnified about 1 6 diameters. 
Cross section through another specimen. 
Another swelling of an arm of a Pentacrinus not so much magnified. 
