88 NOTES ON AVIAN ENTOZOA—LINTON. 
plicatus gen, et. sp. nov., four specimens; Tenia macrocantha sp. nev., 
three specimens; 7. compressa sp. nov., Several specimens. 
6. Pelecanus erythrorhynchus, four birds examined. The stomachs 
contained good-sized fish in different stages of digestion. All of them 
contained very numerous specimens of Ascaris spiculigera in the 
cesophagus and stomach. In the intestine of two of them the adult 
stage of Dibothrium cordiceps was found, thus furnishing proof that the 
pelican is a final host of the trout parasite. 
The above specimens were collected from the Ist to the 10th of 
August, on the shores of Yellowstone Lake. 
The description of a few specimens collected by Mr. P. L. Jouy at 
Guaymas, Mexico, in February, 1891, is also included in this paper. 
These consist of specimens of Ascaris spiculigera, numerous, from stom- 
ach and esophagus of Pelecanus fuscus ; EHchinorhynchus rectus sp. 
nov., from a species of Larus; fragments of Tenia, probably T. capi- 
tella, from Colymbus sp.; fragments of Tania, probably T. fusus, from 
Larus, sp.; fragments of Tenia, probably T. larina, from another 
species of Larus. 
I have not included in this paper any account of the adult stage of 
D. cordiceps of the pelican, having already described it in the article 
cited above. Attention may be called here, however, to the occurrence 
of what I take to be immature specimens of D. cordiceps, in good con- 
dition, in the intestine of the California Gull. It is probable, there- 
fore, that this bird may occasionally become the final host of the trout 
parasite. 
One new genus was met with among the parasites of the duck, Oe- 
demia americana. This genus, which I have named Epision, is charac- 
terized by a singular modification of the anterior part of the body into 
an organ for absorption and adhesion. 
NEMATODA. 
Filaria serrata sp. nov. 
(Pl. tv, Figs. 1-4.) 
The following description is based on a single specimen, a male, from 
the intestine of the hawk, Circus cyaneus hudsonius, Yellowstone Lake, 
Wyoming, August, 1890. It appears to be near F’ leptoptera k.,* but 
differs from that species in some important particulars, especially in the 
character of the spicules. I, therefore, for the present, record it as a 
new species. 
The length of the specimen is about 8 millimeters, the diameter, 0.2 
millimeter. It tapers gradually and uniformly toward the anterior 
end. The posterior end is coiled into a helix and is provided with broad, 
lateral and muscular ale. The spicules are two and very unequal; the 
longer one is about .3 millimeter in length, the shorter only about one- 
*See Schneider, Monogr. der Nem. P. 97, Pl. v, fig. 8, and Von Linstow, Trosch. 
Archiv., 1877, p. 10. 
qT 
Fi 
