NOTES ON AVIAN ENTOZOA. 
BY 
Epwin Linron, Pu. D. 
(With Plates rv—vii1. ) 
The greater part of the material which is described in this paper was 
collected by the author in the summer of 1890 in the Yellowstone Nat- 
ional Park, Wyoming. 
A scientific expedition was sent out in July and August of that year 
by the Hon. Marshall McDonald, U. S. Commissioner of Fish and Fish- 
eries, for the purpose of making a natural-history survey of the lakes 
and streams of the National Park. The author was instructed by the 
Commissioner to investigate specially the question of the excessive 
parasitism in the trout of Yellowstone Lake, and to ascertain if possi- 
ble the source of infection. 
The results of the study of that problem have been published in the 
Bulletin of the U. S. Fish Commission, Vol. Ix, pp. 337-358, Pls. 
OXVII-Cx1x, “A contribution to the Life History of Dibothrium Cordi- 
ceps, a Parasite infesting the Trout of Yellowstone Lake.” In the 
search for the final host of the trout parasite several entozoa were 
found incidentally which were preserved for study. 
The following birds were examined, with the results appended : 
1. Ardea herodias, 3, one bird examined. The stomach contained 
insect larve (Hydrophyllus, Gomphus and Chironomus), with a little 
vegetable material. No parasites. _ 
2. Clangula albeola, 2, one bird examined. The undigested food 
consisted mainly of Ephemerid larvee. No parasites. 
3. Larus californicus, three birds examined. The stomachs contained 
a few ribs and vertebrze of small fish. The entozoa were: Dibothrium 
cordiceps, three immature specimens, D. exile sp. nov., one specimen ; 
Tenia porosa, one specimen, T. filum, several specimens; Distomum 
(2) verrucosum sp. nov., two specimens. 
4. Fuligula vallisneria, 2? ,one birdexamined. The entozoa consisted 
of numerous specimens of Tania compressa sp. nov. 
5. Oedemia americana, four birds examined, one large and three 
Smaller specimens; the entozoa found in the large bird consisted of two 
- specimens of Hchinorhyncus striatus ; the three smaller birds yielded the 
following entozoa: Distomum flerum sp. nov., one specimen ; Hpision 
87 
Proceedings National Museum, Vol. X V—No. 893. 
