190 
AN ACCOUNT OF SOME FIELMINTHES COLLECTED IN THE SUDAN 
Identity of 
Sfrof/gylns and 
Sclerostomitm 
The bursate 
Nematodes 
opportunity to dwell upon the classilioation of the various species that formerly were grouped 
together into the unwieldy genera Strongylus and Sclerostnmum. Under the former name 
Stossich quotes in 1899 no less than forty-two species, and in the latter, twenty-six. Since 
then seventeen others have l)oen added. Strongylns and Sclcwstomum were used by Stossich 
as generic names under which to group two distinct types found in those Nematoda the 
males of which possessed a rayed bursa, viz. those with simple unarmed mouth and those 
with chitinous mouth-capsule, and into these two large genera he brought a number of others 
that more or less exhibited these characters, regarding their names as synonyms. 
Stiles has recently shown, however, that the type-species of Strongylus is, undoubtedly, 
Strmigylus equimis, which is also a type of Sclerost07num, so that these two generic names ai'e 
synonymous, and the more recent Sclei-ostomum must give way to the older name, Strongylus. 
The genus Strongylus, moreover, must now include primarily its own type species, and thus, 
in any division of the various bursate forms, the name must apply to the section containing 
an armed mouth-capsule similar to that of Strongylus equinus —an exactly opposite result 
from the definition determined upon by Stossich. 
Further, it is certain that the several old genera suggested by Molin, such as 
Deletrocephalus, Diaphanoccphalus, Echinocephalus, Eucyathostoimvm, Globocephalus, 
TIistiostrongylus, Kalicephalus and Metastro7igylus, and afterwards suppressed as synonyms 
in these two large genera, must be reinstated in any modern classification that recognises 
distinctive design in the body as a whole, and in its various parts as of generic value, and 
regards species as stable variations, minute but decided in themselves, in the repetition 
of a particular design. 
It appears to me that the characters of the mouth armature in the bursate Nematodes 
must he recognised as of higher than generic value, and our present knowledge of the 
internal anatomy of the various genera of Strongyles calls for their re-gi’ouping into three 
separate families, somewhat after the following manner: — 
Strongylidae 
Nematoda with chitinous 
mouth-capsule, and a bursa 
in the male with true rays. 
Two spicules 
Metastrongylidae 
Nematoda with simple 
mouth, and a bursa in 
the male with true rays. 
Two spicules 
Strongylidae 
Eustrongylida? 
Nematoda with simple mouth, 
and a cuticular bursa in the 
male without rays. One 
spicule 
I 
Anchylostominae 
I 
Strongylinae 
I 
? n. sub-fam. 
Dilated mouth-capsule guarded 
Dilated mouth - capsule 
by teeth or cutting plates, 
guarded by a ring of 
curved dorsally 
I 
setae “corona radiata" 
situated terminally 
.\nchylostomum 
I 
Necator 
Strongylus 
Kalicephalus 
Uncinaria 
Triodontophorus 
Gyalocephalus 
Cylichnostomum 
Eucyathostomum 
Qlsophagostomum 
etc. 
