INTERNAL PARASITES 183 
variable number of segments 
designated proglottides. The 
scolex is armed with a series of 
hooks by which it becomes at- 
tached to the intestinal mucosa 
of the host. Each proglottid or 
segment of the worm is virtually J i 
an individual and is bisexual, 7,24, Segment of, Devons, sehin 
The segments are not provided gans. Enlarged. (Ransom) - 
with an alimentary canal, but 
absorb nourishment directly from the intestinal contents of the host. 
As the terminal segments in turn mature, they are separated from 
the worm and are discharged in the droppings. 
Species of cestodes. A large number of species of tapeworms 
have been reported as occurring in the intestines of domesticated 
and wild birds. Ransom has examined nine species in American 
chickens and turkeys as follows: In chickens, Hymenolepis carioca, 
Choanotaenia infundibulum, Davainea tetragona, D. echinobothrida, 
D. proglottina, Amoebotaenia sphenoides; in chickens and turkeys, 
D. cesticillus, Hymenolepis cantaniana; in turkeys, Metroliasthes 
lucida. He notes that the tapeworms of American ducks, geese, and 
pigeons have not yet been investigated. Neumann lists four more 
species as having been found in fowls. These are Cotugnia diagono- 
pora, Taenia fasctolaris, T. exilis and Bothriotaenia longicollis. 
Tapeworms found in the various birds are listed by Neumann as 
follows: 
Turkey: Choanotaenta infundibulum, Metroliasthes lucida, 
Davainea cantaniana, D. cesticillus, D. friedbergeri, Hymenolepis 
carioca, H. musculosa, H. meleagris, Not named. 
Pheasant: Choanotaenia infundibulum, Davainea echinoboth- 
rida, D. cantamana, D. friedbergeri, Hymenolepis phasianina. 
Pigeon: Choanotaenta infundibulum, Davainea echinobothrida, 
D. crassula, Bertiella delafondt. 
Duck: Hymenolepts anatina, H. gracilis, H. sinuosa, H. coronula, 
H. parvula, H. megalops, H. lanceolata, Choanotaenia infundibulum, 
Davainea crassula, Fimbriaria fasciolaris. 
Goose: Hymenolepis lanceolata, H. setigera, H. gracilis, H. 
fasciata, H. sinuosa, H. tenuirostris, Fimbriaria fasciolaris. 
Neumann considers tapeworms as occurring infrequently in pig- 
eons and rarely present in sufficient number to cause trouble. In 
ducks they exert feeble pathogenic action. Hymenolepis setigera and 
