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Joumal of Agricultural Research v 0 i. xxviii, no. 7 
ADDENDUM 
Since the writing of this paper Railliet (5) has published a description of Stron¬ 
gylus Utr acanthus Mehlis and has shown that it is identical with Trichonema 
arcuata Cobbold and with Cylicostomum insigne Boulenger. The name of the 
species therefore becomes Trichonema tetracanthum (Mehlis, 1831) Railliet and 
Henry, 1919. Cyathostomum tetracanthum Looss is a different species and Railliet 
has named it Trichonema aegyptiacum. 
Since in raising Ihle’s subgenera to genera, C. insigne Boulenger was referred to 
the genus Cylicocylus, the latter will fall as a synonym of Trichonema. Cyli¬ 
costomum, with the type C. aegyptiacum , is therefore available as a generic name 
for species of the restricted genus Cylicostomum as used in this paper, and equiva¬ 
lent to the subgenus Cylicostomum as used by Ihle. 
Railliet ( 6) has divided the genus Strongylus into four subgenera. One of 
these, Decru sia, contains the strongyle of the elephant. The three subgenera of 
the horse strongyles, and the distinguishing characteristic of each are as follows: 
Strongylus, two sub ventral and two dorsal teeth; Alfortia, no dorsal teeth; 
Delafondia, two dorsal teeth. 
Accordingly the four species are Strongylus equinus, Str. (Alfortia ) edentatus , 
Str. (Delafondia) vulgaris , Str. ( Delafondia ) asini. 
Gertrud Theiler in a thesis published in 1923, which has just come to hand, 
has described a new species of Cylindropharynx, C . intermedia , from the South 
African Zebra. It is distinguishable from the other four species as given in the 
key in this paper in that the specimens of <7. intermedia are less than 12 mm. 
long and the length of the mouth capsule is 4 to 5 times as great as its greatest 
width. 
LITERATURE CITED 
(1) Boulenger, C. L. 
1920. ON SOME NEMATODE PARASITES OF THE ZEBRA. Parasitology 12: 
98-107, illus. 
(2) Ihle, J. E. W. 
1922. OVER DE VERDEELING VAN HET GESLACHT CYLICOSTOMUM. Tijdsch. 
Diergeneeskunde 49: 135-136. 
(3) - 
1922. REPORT OF THE COMMISSION APPOINTED TO INQUIRE INTO THE 
SCLEROSTOMIASIS IN HOLLAND. 1. ZOOLOGICAL PART. V. 1. ThE 
ADULT STRON GYLIDS (SCLEROSTOMES) INHABITING THE LARGE 
intestine of the horse. 118 p., illus. The Hague. 
(4) Leiper, R. T. 
1911. SOME NEW PARASITIC NEMATODES FROM TROPICAL AFRICA. PrOC. 
Zool. Soc. London 1911: 549-555, illus. 
(5) Railliet, A. 
1923. le veritable strongylus tetracanthus mehlis et son role 
pathogene. Ann. Parasitol. Humaine et Comp. 1: 5-15. 
( 6 ) - 
1923. LES STRONGYLES (ANCIENS SCLEROSTOMES) ET LES STRONGYLOSES 
proprement dites. Rec. Med. V6t. 99: 377-396. 
(7) Yorke, W., and Macfie, J. W. S. 
1918. STRONGYLIDAE IN HORSES. IV. GYALOCEPHALUS CAPITATUS, 
looss. v. gyalocephalus equi, sp. n. Ann. Trop. Med. and 
Parasitol. 12: 79-92, illus. 
(8) - 
1920. STRONGYLIDAE IN HORSES. IX. CYLICOSTOMUM TRIDENTATUM, 
SP.N. X. ON THE GENUS POTERIOSTOMUM, QUIEL. XI. SPECIES 
FOUND IN WEST AFRICA AND JAMAICA. XII. CYLINDROPHARYNX 
RHODESIENSIS, SP.N. XIII. CYLICOSTOMUM TRIRAMOSUM, SP.N. 
Ann. Trop. Med. and Parasitol. 14: 153-179, illus. 
