2 
Tapeworms from Ostrich 
hooks exhibiting a rather irregular alternation of large and small forms. The 
rostellum itself consists of a short broad central portion, 0-48 mm. diameter, 
bearing the hooks, surrounded by a band of parenchymatous tissue, 0-81 mm. 
diameter, in shape like a pneumatic tyre, the whole bearing a remarkable re¬ 
semblance to the scolex (Plate I, fig. 1) of Davainea brotogerys Meggitt, 1915. 
This appearance has been figured by Zilluf (1912, 17) for a form he calls 
Davainea struthionis but which is instead probably identical with D. beddardi. 
With the exception of the armed collar posterior to the rostellum, figured by 
Dujardin (1845, Plate 9, fig. LI) and mentioned by Stossich (1895) and 
Blanchard (1891 a, 435) for D.frontina (Duj.), in no other species of Cotugnia or 
Davainea has this modification of the scolex been mentioned, and absence of 
comment in the case of so noticeable a structure must be held to imply the 
absence of the structure itself. It is impossible for this appearance to have 
been caused by the method of fixation or for it to be a temporary character 
in any way. It was characteristic of each of the 12 scolices of D. beddardi 
and all those of C. brotogerys , although the two forms were fixed by different 
reagents. The close similarity of the two scolices is interesting in view of the 
fact that one genus has a double and the other only a single set of genital 
organs in each proglottis, and forms yet another comment, if one were needed, 
upon the inadvisability of distinguishing species by the size and external 
appearance of the scolex alone unaccompanied by any internal morphological 
difference. A neck is absent. All proglottides seen were broader than long: 
in those containing mature eggs the length approximated to the breadth. 
The longitudinal musculature (Plate I, fig. 3) is arranged in two layers, 
a stronger internal one of numerous bundles of small fibres and a weaker 
external one, often absent, of isolated fibres. Separating these two is a thin 
layer of transverse muscles, while a second band exists internally to the inner 
longitudinal muscle layer. In the extreme anterior portion of the strobilus 
(Plate I, fig. 4), the two longitudinal muscle layers merge into one, the 
separating transverse muscles disappearing. The genital pore is unilateral 
opening at the posterior two-thirds of the proglottis margin. There is a deep 
narrow genital cloaca at the bottom of which open the genital ducts. Both 
male and female ducts pass dorsal to the longitudinal excretory vessels. The 
cirrus-sac is small, not extending beyond the longitudinal nerve-cord and, 
as far as could be ascertained in the state of preservation of the material, 
had a very feeble muscular structure. The cirrus is unarmed and that portion 
of the vas deferens inside the cirrus-sac is coiled several times in the form of 
a very twisted piece of rope. The coils of the vas deferens stretch from the 
inner end of the pouch half-way across the proglottis, then break up into 
the vasa efferentia. Neither vesicula seminalis nor sacculus accessorius could 
be observed. The testes are small, approximately 100 in number, and fill 
the whole of the dorsal surface of the proglottis, extending laterally to the 
longitudinal excretory vessels. Proglottides containing the sexually mature 
female organs were absent. From the immature segments found, it could be 
