some Parasitic Nematodes. 5OL 
there are deep grooves in the cuticle running from the inter- 
labia to the base of each lip. The caudal papille of the male 
(figs. 7, 8) in every case agree in number and arrangement, 
and are found to be in accordance with the figure given by 
v, Linstow (1884). The figure given by Schneider (1866) 
for Ascaris ensicaudata is incomplete, the four small pairs of 
ventral postanal papille having been omitted. ‘These are 
very minute and by no means easy to detect in some specimens. 
The number (eight) of pairs of postanal papilla given by 
v. Linstow (1909) for “ Ascaris ensicaudata” seems to be 
crroneous. In both forms the vulva divides the body nearly 
in the proportion of 2:3. There is no appreciable difference 
Fig. 4. 
 ———$_$_________4 
O'lMnN, 
Porrocecum ensicaudatum. Dorsal lip, external aspect. 
Lettering as in fig. 3, 
in the arrangement of the female organs, and the eggs are of 
the same dimensions (about 0°1 x 0°075 mm.). 
No difference could be detected between the material from 
blackbirds and that from starlings. As has been implied 
already, cervical alze are absent in P. ensicaudatum. This is 
contrary to the statements of some authors (Zeder, Rudolphi, 
Dujardin), who have described what was presumably the 
same species, and this discrepancy is difficult to explain. In 
order to confirm this point, transverse sections, taken close to 
the head, of the two species were compared, and, while in 
