MY XICOLA. 307 
When Sir A. G. Bourne published his account of Haplobranchus, Dr. Leidy’s papers! 
on Manayunkia speciosa were not alluded to, but it was thought that there might be a close 
connection between the American and the British forms. Further examination shows 
that this supposition was correct. Thus the body in both consists of twelve segments, 
including the “head,” the cephalic region having in Manayunkia two stems, Leidy’s 
“ lophophores,” each with eighteen ciliated brownish “‘ tentacles,” the two inner larger than 
the others and supplied with green blood. Two eyes lie at the side of the gullet and 
present “vitreous humour and a choroid capsule.” Haplobranchus, again, has only four 
filaments projecting from the stem with the green “ palpi’ 
structure is the same, and the blood in each is green and enters the 
4 ? 
internally, but the plan of 
“palpi” only. A 
large vessel occurs in Manayunkia on each side of the alimentary canal so as to give it a 
green coat, and a lateral branch is given off in each segment. There is an incessant 
pumping of blood into the ‘ 
intestinal canal is ciliated in the seventh segment and at the posterior end. A large elliptical 
“palpi” and contraction and expulsion from them. The 
organ extended from the posterior part of the head to the third segment and Leidy thought 
it a testicle. It probably is the modified segmental organ seen in the third segment of 
Haplobranchus, and the American author’s ovaries in the fourth to the sixth segment 
(inclusive) may represent the paired bodies mentioned by Bourne as occurring in the 
tenth to the twelfth segments at the base of the feet, though this is conjectural. Leidy 
found young ones in the tubes of mud and he thought the young were developed there. 
Moreover the tubes were sometimes branched like a candelabrum on pieces of bark in Hee 
River, New Jersey, for, like Haplobranchus, it is a fresh-water form. On the other hand 
Haplobranchus lives amidst the mud. The hooks and bristles of the two forms closely 
correspond, so that on the whole the generic name Manayunkia should stand, though Sir 
A. G. Bourne’s title and the excellence of his descriptions and figures have due weight. 
The increase of the divisions of the prostomial stems in the American form is a prominent 
feature. Dr. Leidy considered that Manayunkia was closely related to Amphicora 
fabricia, though in the latter the blood is red. 
SuB-Famity.—ErRioGRaPHIDEA, Malmgren. 
The Hriographidide of Malmgren may be conveniently regarded as a sub-family 
of the Sabellidee. The structure of the body-wall, for instance, is not more remarkable 
than that found in Chone and Euchone, and there is no apparent advantage in continuing 
the isolation of the group. 
Genus CLXXV.—Myxticoia, H. Koch (fide Grube and Claparéde). 
Myzxicola, Grube (1855) and Sars; Hriographis, Grube; Arippasa, Johnst., 1865 ; 
Leptochone, De Quatrefages and Levinsen ; Gimnosoma, De Quatrefages. 
Cephalic plate devoid of a collar; triangular plate passes forward in the mid-dorsal 
region between the branchial fans and another ventrally. Two short tentacles. Closed 
1 “Proc. Nat. Sc. Philad.,’ 1858, p. 90, and 1883, p. 204; pl. ix, figs. 1—24 (1884). 
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