AET. 24 THREE NEW NEMATODES — SKINKER 5 



Hosts. — American varying hare {Lepm americanus), coyote {Ganis 

 Testes).'^ 



Location. — Small intestine. 



Distrlhution. — United States (Cheboygan County, Mich,, and 

 Olympia, Wash.). 



Type specimen. — U.S.N.M. Helm. Coll. No. 28463. 



Remarks. — This species lacks the annulations found on the tail in 

 mature females of Passdlurus ambiguus. It is impossible, however, 

 to determine in all cases in the earlier literature whether the author 

 was describing a form in which the mature females possessed a monili- 

 form tail. Both Schneider (1866) and von Linstow (1899), as well 

 as Rudolphi (1819), fail to mention annulations if they were present 

 in the mature females described by them. Dujardin (1845), on the 

 other hand, mentions them. This leaves it a question as to whether 

 one or more species of Passalurus have been observed up to the time 

 of this report, but P. amhiguus is now established as showing a 

 moniliform condition in the female tail. The spicules in both species 

 are about the same size, but they differ slightly in shape. The anal 

 papillae of P. nonanulatus are not in agreement with those in the 

 description of P, ambiguus given by Danheim and Ackert (1929) 

 and that of Hall (1916) ; therefore the two species differ in this 

 respect. Danheim and Ackert give the number of these papillae for 

 P. aiiibiguus as five, and so also does Hall. The writer has examined 

 in ventral view many specimens of P. nonanulatus and finds only 

 the two pairs of anal papillae as described. Hall (1916) and Dan- 

 heim and Ackert (1929) agree in reporting for P. amhiguus an 

 unpaired papilla located directly behind the cloacal aperture, but 

 among other authors there is little agreement in regard to the number 

 of perianal or adanal papillae assigned to this species. In favorable 

 mounts of P. amhiguus the appearance of this " unpaired " papilla 

 is such as to suggest that it represents the fusion of two papillae. 

 Seurat (1916) describes and illustrates three pairs of large perianal 

 papillae and a small pair situated immediately posterior to the cloacal 

 aperture. Von Linstow (1899) describes and illustrates only two 

 pairs of perianal papillae. Dujardin (1845) does not mention any 

 such papillae, and Schneider (1866) indicates only one pair as 

 situated near the cloacal aperture, although another pair is described 

 and illustrated by him as approximately at the side or " fast seitlich 

 stehend." Yorke and Maplestone (1926) describe three pairs of large 

 " pericloacal papillae." The pair of papillae situated at the point 



*The specimens of this species from the coyote (Oanis lestes) (U. S. N. M. No. 26738) 

 were collected by Dr. E. B. Cram, the Intestine of the host having been sent from Olym- 

 pia, Wash., to the Bureau of Animal Industry by Dr. Glenn R. Bach, formerly of the 

 Bureau of Biological Survey. The presence of Passalurus nonanulaius in a carnivore 

 undoubtedly represents a case of spurious parasitism following the ingestion of the normal 

 host, the hare, by the coyote. 



