204 
Sderostomes of the Horse 
brief communication no attempt has been made to determine the 
British representatives of the genus since Mehlis’ old species C. tetra- 
canthum was broken up by Looss (1900, 1901). 
Altogether eight species were obtained by me in the Midlands; in 
addition to the three new forms which I have named G. euproctus, 
C. insigne and C. goldi, the following were also observed: 
C. poculatum Looss. 
C. calicatum Looss. 
C. nassatum Looss. 
C. coronatum Looss. 
C. hicoronatum Looss. 
It is interesting to note that Cylichnostomuni tetracanthum (Mehhs) 
Looss is not in this list, neither was it observed by Leiper. As Looss 
was unable to obtain Mehlis’ original paper (1831) he decided to choose 
as type species that form which occurred most commonly in Egypt; if 
this species proves to be absent from European countries his choice will 
turn out to have been an unfortunate one. 
There is, however, nothing to gain from Mehlis’ account of his 
Strongylus tetracanthus which is very scanty; I have looked up his 
paper in Oken's Isis (1831) but the few lines devoted to this worm 
would apply equally well to many other species of Cylichnostomuni, 
the only definite and useful information refers to the size of the worms, 
which is given as 6-7 lines, i.e. about 15-17 mm., this is certainly larger 
than Looss’ C. tetracanthum sensu stricto. 
The diagnoses of the new species observed are given below: 
Genus Cylichnostomum Looss 1901. 
Cyathostomum Molin 1861. 
Cylicostomum Railliet et Henry 1902. 
Cylichnostomum euproctus sp. n. 
Specific diagnosis. Cylichnostomum^ : Head marked off from the 
body by a slight constriction (Text-fig. 1 a, b), its diameter 110-130/x. 
The mouth-collar is comparatively high (33-46/x) and somewhat 
flattened towards its lateral margins so as to appear nearly hemispherical 
when seen in lateral view (Text-fig. 1 a). The lateral head papillae are 
not prominent, the submedian head papillae are very short and spherical 
in shape. 
‘ For a definition of the genus Cylichnostomum of. Looss (1901). 
