W. A. Riley 
91 
There are numerous European records of the occurrence of this hookworm 
in foxes, but I do not know of any explicit American record. The adult hook¬ 
worms from the fox which I have at hand are all of Uncinaria polaris, but I am 
not warranted in concluding definitely that all of the hookworm eggs which I 
have noted in faeces examinations are of this species. 
Ancylostoma caninum is common in cats and dogs in this region. Hall 
reports it in 23 out of 67 dogs, or 34 per cent, at Detroit, Michigan. 
My records for Minnesota dogs are not extensive enough to justify a 
statement of percentages, I have found it in ten out of 30 cats examined. 
It is a significant fact that it is a common practice of fox growers to use cats 
as foster mothers of fox puppies if the vixen is unable to provide for them. 
Belascaris marginata (Rud. 1802) Leiper, 1907. 
(Synonyms: Ascaris marginata Rud. 1802 'pro parte.) 
This common ascarid of dogs frequently occurs in foxes and is the cause 
of serious trouble in the case of the pups. By most growers it is considered the 
most common, or practically the only “ worm” of foxes, owing doubtless to the 
fact that the worms are to be found in the droppings. My examinations would 
lead me to think it less frequent than are hookworms. The latter were found in 
26 out of 30 samples from four different farms, while ascarids were present in 
but six. 
Belascaris vulpis (Frolich, 1789) Railliet and Henry, 1911. 
(Synonyms: Ascaris vulpis Frolich, 1789; Ascaris tnquetra Schrank, 
1790.) 
Railliet and Henry (1911) recognise the Ascaris vulpis of Frolich from Vulpes 
vulpes, as a valid species closely related to Belascaris marginata. The spicules 
are of the same length as in the latter species, but the caudal extremity of the 
body is excavated in a gutter-like manner (creusee en gouttiere) and almost 
triangular with caudal wings well developed. 
It is to be noted that among 200 ascarids from 25 Massachusetts 
dogs, Walton (1916) found two which he regarded as Ascaris triquetra 
Schrank (= B. vulpis). 
Crenosomu semiarmatum Molin, 1861. 
(Synonyms: Strongylus decoratus Creplin, 1847; Liarhynchus vulpis 
Dujardin, 1845.) 
Reported by Bremser, Dujardin and Creplin, as found in the lungs and 
trachea of Vulpes vulpes. 
Dioctophyme renale (Goeze, 1782) Stiles, 1901. 
(Synonyms: Ascaris visceralis Gmelin, 1789; Strongylus gigas Rud., 1802; 
Eustrongylus gigas Diesing, 1851.) 
The giant kidney-worm was reported for both the European and the 
common American fox, by Rudolphi, 1819. 
