302 
Tapeworms of Poultry 
with the exception of a paper by Khitrow (1900) inaccessible to me, the species 
has not been recorded. Pasquale’s description is incomplete in many respects 
so that, although through the work of Fuhrmann (1909) on the species 
C. crassa Fuhr., C. collini Fuhr. and C. polycantha Fuhr., the genus is 
well defined, the type species has remained practically undescribed. Three 
complete tapeworms from chickens in Mesopotamia were handed to me for 
identification. These I believe to be specimens of C. digonopkora (Pasq.), 
and take the opportunity to compile as full an account as possible of the 
anatomy of this type species. 
The sizes of the strobilae are 107 mm. x 4 mm., 80 mm. x 4 mm., 
26 mm. x 2-5 mm. and 22 mm. x 2*5 mm. The scolex (PL XVII, fig. 9) is 
0-66 mm. long x 1-07 mm. broad, with four unarmed suckers 0-36 mm. long x 
0-25 mm. wide, arranged two dorsally and two ventrally. The rostellum is 
0-16 mm. in diameter, armed with a double crown of hooks 0*0122 mm. long, 
of the usual Davainea shape, the hooks on each row being of the same size 
and alternating with each other, with but little difference in their anterior 
level. The rostellum itself is a simple muscular structure sunk between four 
large lobes which completely hide it. All proglottides are broader than long. 
These measurements do not agree with those quoted by Stiles (1896, p. 30) 
“ Strobila 40 mm. to 80 mm. by 8 mm. broad and in contracted condition 
about 1 mm. thick; head 1*4 mm. by 1*12 mm., rostellum with a crowded 
crown (in a single row) of very small hooks 8*35 fi long; base of rostellum 
0*22 mm. by 0*15 mm., suckers globular, prominent, 0*35 mm. in diameter. 
Neck short. Anterior segments broader than long, posterior segments longer 
than broad. Genital pores double in about the middle of the lateral margins; 
two ovaries in each segment; eggs evidently arranged in egg sacs.” 
These differences in the measurements and the shape of the proglottides, 
characters indefinite and liable to variation, are probably the result of individual 
variation in the tapeworms examined and can therefore be safely neglected. 
The longitudinal musculature (PI. XVII, fig. 11) is in two layers. The inner¬ 
most (l.m.) consists of numerous bundles of loosely packed fibres, approxi¬ 
mately 20 fibres to a bundle. Internally it is bounded by a single (t.m.) and 
externally by a double ( t'.m '.) layer of transverse muscles, the two layers of 
the latter separated by a narrow stratum of parenchyma. Numerous dorso- 
ventral fibres cross these two last layers and pass between the inner longi¬ 
tudinal muscle bundles. Externally to the transverse muscles mentioned is 
a widely diffused layer of longitudinal muscles (V.m'.). Internally these form 
very compact bundles of very few fibres, approximately 10 per bundle, but 
diminish gradually to isolated fibres which do not extend as far as the cuticle. 
Both these two longitudinal muscle layers extend posteriorly into segments 
containing mature eggs, but only the inner extends anteriorly into the scolex. 
There it is much stronger, the bundles being more numerous and more compact, 
and forming an almost continuous layer which ceases at the posterior half of 
the suckers. 
