ART. 16. PARASITIC ROUND WORMS OF THE RABBIT CHANDLER. 5 



diameter to from 305 to 340 [x. The diameter of the head anteriorly 

 is only 80 [x, but 110 [j. from the anterior end it has widened out to 

 150 [X. Graybill gives the diameter of the head as 119 ^. The vulva, 

 guarded by a pair of inconspicuous lips, is situated about one-fifth 

 the length of the body (3.6 to 4.5 mm.) from the posterior end, its 

 location being readily recognized by the abrupt diminution in diame- 

 ter of the body and the angular bending of the body at this point. 

 The vagina is very short, joining the divergent ovijectors almost im- 

 mediately. The muscular portions of the ovijectors can hold four or 

 five eggs apiece ; there is no well-marked sphincter between the mus- 

 cular and nonmuscular portions, but a very strong sphincter sepa- 

 rates the nonmuscular portion from the uterus. The terminal por- 

 tion of the uterus is also muscular, and can contract so that only one 

 egg at a time can reach the sphincter. The eggs in the Texas speci- 

 mens measure 80 to 92 [x by 56 to 64 [x, whereas Graybill records 

 measurements of 76 to 86 [x by 44 to 45 [>. in the New Jersey speci- 

 mens.^ 



In spite of a number of slight discrepancies in the descriptions 

 and measurements of the Texas and New Jersey si^ecimens, it is 

 very unlikely that more than one species is represented. My meas- 

 urements were made from living narcotized worms, whereas Gray- 

 bill's may have been made from preserved and prepared specimens,' 

 which would account for some of the differences. 



When present in considerable numbers this worm produces a very 

 marked erosion and ulceration of the stomach wall. The worms are 

 found adhering firmly to the mucous membranes, and in some in- 

 stances seem to have their heads buried deeply in the wall. In 

 most of the rabbits examined only from one to five or six worms 

 were found, but in one specimen about 50 adult worms and a number 

 of immature specimens were found. Part of the material described 

 above has been deposited in the Helminthological Collections of the 

 U. S. National Museum, Nos. 7735 and 7736. 



LITERATURE CITED. 

 Graybill, H. W. : 



1923. A New Genus of Nematodes from the Domestic Rabbit. Parasit., 

 vol. 15, pp. 340-342. pi. 11. 

 May, H. G. : 



1920. Observations on the Nematode genus Nematodirus with Descrip- 

 tions of new Species. Proc. U. S. Nat. Mus., vol. 58, pp. 577-588, 

 pis. 29-35 

 Ransom, B. H. : 



1911. Two New Species of Parasitic Nematodes. Proc. U. S. Nat. Mus., 

 vol. 41. pp. 363-369 



