some Parasitic Nematodes. 495 
by Dr. L. W. Sambon in 1997. For the opportunity of 
examining it the writer is indebted to him and to the 
Director-in-Chief, Wellcome Bureau of Scientific Research. 
Thanks are also due to Mr. R. J. Ortlepp, of the Prosectorial 
Department of the Zoological Society, for kindly supplying 
some information from the records of the Society. 
This interesting form is very closely related to the Oxyuris 
evoluta, v. Linst., described by Smith (1908) and by Hall 
(1916) from Erethizon dorsatum and LE. epivanthum,  v. Lin- 
stow’s (1899) specimens from Acanthion brachyura seem to 
have been immature, and his description is so brief that it is 
difficult to be certain whether those of the later authors were 
of the same species. Smith’s specimens were also immature. 
The American authors, however, have described the presence 
of cervical ale, while v. Linstow mentions a spindle-shaped 
swelling of the cuticle anteriorly, which is probably another 
interpretation of the same structure. 
In the present material not only are the ale apparently 
absent, but no cuticular swelling can be detected. Unfortu- 
nately the material consists of females only, and the specific 
characters depend mainly upon measurements, which can 
best be given in the form of a table. Most of the differences 
in dimensions between W. samboni and Oxyuris evoluta might 
be due merely to individual variation; but, besides the 
absence of cervical ale, the more anterior origin of the 
characteristic vaginal outgrowth and its much greater length 
in the older females, and the somewhat larger dimensions of 
the eggs, appear to be valid specific characters. In the 
absence of a fuller description of v. Linstow’s original 
material, therefore, we may regard the form under con- 
sideration as distinct from O. evoluta. It may be mentioned 
here that the intestinal dilatations described by Hall do not 
seem to be constant in magnitude and position, but vary 
considerably, in W. sumbont, 
Sambon (1907a & b), under the name of Wellcomia 
mitchelli, briefly described a form from the Cape Jumping-hare 
(Pedetes caffer). Here again, unfortunately, the description 
had to be based on females only *, and the measurements 
indicate no real difference between W. mitchelli and W. samboni 
(see table below). ‘The wide differences of host and geogra- 
phical distribution, however (unless, of course, the infection 
had been acquired in captivity), seem to justify the assump- 
tion that the species are not identical, 
* Dr. Sambon believes that a male was seen, but was unhappily’ lost, 
He thinks it had a very long slender tail, but no other details are 
available. 
