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VOL. ag 
1892. PROCEEDINGS OF THE NATIONAL MUSEUM. 101 
Epision plicatus sp. nov. 
(Pl. vi, Figs. 49-53.) 
Anterior part of body (head) a lamellate unsymmetrical organ, which 
_ consists of an elongated auricular pointed flap, deflected marginally 
and forming an angle with the body proper, and a shorter rounded lobe 
at the opposite margin. his leaf-like organ is more or less crimped or 
_ folded, especially near the shorter lobe, and on the anterior edge; it is 
crossed by fine transverse lines, which upon enlargement appear due 
to a segmented condition of the organ; two pairs of vessels rise near 
its extreme tip and are continuous with the longitudinal vessels of the. 
_ body proper. Body nearly linear, flattened; segments beginning im- 
mediately behind the head, not distinct. Reproductive organs rudi- 
mentary in specimens examined, but from their position along the me- 
dian line of the strobile, and their resemblance to similar stages of de- 
velopment in the Dibothriide, it is probable that the reproductive 
apertures are median. 
Longest specimen, 23 millimeters in length and 1.5 millimeters in 
breadth. 
HABITAT: Oedemia Americana, intestines, Yellowstone Lake, Wyo- 
ming, August, 1890. 
The foregoing description is based on four specimens from the Black 
_ Scoter, the largest 23 and the smallest 6 millimeters in length. The 
| breadth of the head of the larger specimen was about 3.2 millimeters, 
. breadth of the body near the head 1 millimeter, and the length of the 
| rather indistinct segments near the head 0.2 millimeter; greatest 
| breadth of the body 1.5 millimeters; near the posterior end the breadth 
| decreased to about 0.8 millimeter. 
_ Following are the dimensions in millimeters of the smallest speci- 
men: Length, 6; breadth of head, 1.8; length of head, 0.7; breadth 
_ of body near head, 0.35; breadth of body, posterior, 0.55. 
The segments, which are rather indistinct, appear as if in pairs, or 
_ rather each is divided into two nearly equal parts by a faint transverse 
_ line. 
_ The head is finely serrate on its margins, and presents a minutely 
_ Segmented appearance when magnified. It is therefore not to be re- 
| garded as homologous with a scolex, but rather as the anterior portion 
_ of the strobile modified into an absorbing and adherent organ. 
None of the specimens had reproductive organs developed sufficiently 
| to fix the systematic position of these singular forms. Sections made 
from a series of posterior segments of a medium sized specimen show 
_ that there is no distinct segmentation in the inner portions of the 
'Strobile. The genitalia are represented by small, oblong clusters of 
- granules lying transverse to the axis of the bod y and crowded together 
z along the median region of the body. There are no external apertures, 
_ but the arrangement of the incipient genitalia, and of the longitudinal 
muscle fibers and the longitudinal vessels, as seen in these sections, in- 
_ dicates relationship with the Dibothriide. 
PRI 
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Kags STS 
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