OCCURRENCE OF HELIGMOSOMUM BRASILIENSE 
TRAV. TN ENGLAND. 
By G. C. DUDGEON, C.B.E., F.E.S., etc. 
Wellcome Bureau of Scientific Research. 
In making the examination of a series of 400 rats, Helignwsomum krasiliense 
was found in 6 per cent, of those examined. The rats were all of the one 
species, Epimys norvegicus, and were chiefly from London and suburbs; the 
exceptions being one from Berkshire, one from Hampshire and two from 
Hertfordshire. , 
The worms are found, generally, in the upper third oi the small intestine, 
and the measurements, where they differ from those previously described for 
this species, are given. , 1-00 
Male. In all cases, measured, the average length of the male is -.-8 mm. 
and the width 0-087 mm., giving a mean ratio of 32 : 1. The spicule averages 
0-561 mm. The lobes of the bursa are asymmetrical in form; the latero- 
ventral and externo-lateral rays of the left lobe run parallel, and generally 
contiguous, throughout their length. The right lobe is much thickened and 
normally enrolled into a bar. The dorsal lobe is short and bears three rays, 
the central one terminating in two branches, which are again divided, the 
inner digitation bearing a small node on its outer edge, the outer digitations 
being slightly curved outwardly. 
Female. The female averages 3-7 mm., with a thickness of 0-106 mm., 
giving a mean ratio of 34 : 1. 
The worm has 14 longitudinal ridges visible in the median section; those 
of the lateral area are deeper and more prominent than either the dorsal 01 
ventral ones. These ridges diminish in number towards the anterior end, and 
appear to be all present posteriorly, but of more uniform and much reduced 
dimensions. . 
A comparison of the measurements of British with those of Australian 
specimens may be of interest: Heligmosomum brasiliense Trav. was described 
and figured by T. Harvey Johnston, M.A., etc., in the Proceedings of the 
Royal Society of Queensland, vol. xxx. p. 56, for 1918, but with some rather 
remarkable differences in measurement. The general form of the worms from 
both continents is the same. 
