1909.] ON PARASITES OF BIRDS ALLIED TO THE GROUSE. 363 
Fig. 11. Magnified view of mature proglottis of D. wrogalli. gp., genital pore; 
_-0v., OVary: p., penis; ¢., testes; v., vagina: vié., vitellarium ; w.v., excre- 
tory system. ; 
12. Ova of D. urogalli, showing the ovum and yolk-vesicles. 
13. Longitudinal horizontal section through the same, showing the great 
extension of the excretory transverse canals, and the ova scattered zn egg- 
capsules. 
PratEe LX. 
Fig. 14, A similar section through the last proglottis, showing the enormous trans- 
verse canal at the level of the breaking zone and the excretory pore e.p. 
15. Ova of D. urogalli more advanced than those shown in fig. 12, showing the 
onchosphere and traces of the yolk-vesicles. 
16. An isolated hook from the same. 
17. Transverse section of the walls of intestine of a fowl, showing Tenia 
botriopliti embedded in the deeper layers of the intestinal wall. aa., in- 
testinal mucosa; 6., muscular layers; sp., peritoneal lining; ¢¢., anterior 
ends of the tape-worms; ¢., mass of exudate produced by the irritation of 
the head of the Tenia. (From Piana, Mem. Ac. Sci. Istit. Bologna, series 
4, vol. 11. 1880, p. 387.) 
18. Head of Hymenolepis microps (Diesing), highly magnified. 
19. Section through the retracted proboscis of the same, highly magnified to 
show the arrangement of the hooks. 
20. Isolated hooks of the same seen under {5 oil immersion-lens. 
21. A few mature proglottides of the same, taken from about the middle of the 
body. 
22. Onchospheres of H. microps in the characteristic three envelopes. 
23. Hooks from the same. 
4, Internal Parasites of Birds allied to the Grouse. By 
A\. Jd, (Suni, Wiel deloms IDS, IeltSn Jena, 
Fellow and Tutor of Christ’s College, Cambridge, and 
Reader in Zoology in the University. 
| Received December 18, 1908. | 
The following is a brief enumeration of the Cestode, Trematode, 
and Nematode parasites of the Grouse, the Ptarmigan, the 
Blackeock, and the Capercaillie. To these I have added the 
Willow-grouse and the Hazel-hen, although these birds, unlike 
the three former, are not denizens of the British Isles. It will be 
noticed that but two Nematodes, 7richosoma longicolle (Rud.) and 
Heterakis papillosa (Bloch), and two Cestodes, Davainea wrogalli 
and Hymenolepis microps, are common to our grouse and to its 
allies. The first named round worm and the tape-worm are 
found in all three, Blackcock, Capercaillie, and Grouse, and in none 
of the other nearly allied birds; whilst Heterakis papillosa has 
been recorded from the Ptarmigan, the Capercaillie, the Hazel- 
hen and the Grouse, besides from many other birds. 
Heterakis perspicillum (Rud.) also occurs in three hosts, in the 
Blackeock, the Hazel-hen, and the Capercaillie. All the other 
Nematode parasites mentioned occur in a single host, except 
Heterakis compar (Schrank) which is found in both the Ptarmigan 
and the Capercaillie. Of the Cestodes, Davainea wrogalli and 
Hymenolepis microps occur in the Grouse, the Blackgame, and the 
Capercailhie. 
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