NO. 2131. 



NEMATODE PARASITES OF RODENTS— HALL. 



185 



Von LinstoY.' had only a single specimen, an immature female, and 

 states that since a satisfactory specific diagnosis can not be made only 

 a provisional specific name can be given. See FUaria pistiUaris. 



FILARIA SCAPICEPS Leidy, 1886. 



Specif c dlagnosh. — F'darla (p. 179) : Body tapering nearly equally 

 at both ends. Anterior extremity narrows abruptly and forms a 

 sort of neck posterior of the head. Head without visil)le papillae. 

 Mouth aperture very small. The cuticle shows a fine obscure trans- 

 verse striation. 



Male 1-2 to 14.5 mm. long and 310 to 375 jx thick. The head is 

 about 100 p. in diameter. The esophagus is about 8G0 ix long. The 

 testis extends anterior of the pos- 

 terior extremity of the esophagus. 

 Tail conical, curved, provided 



i/iomm. 



Fig. 2-13.— Fn.AHiA scapiceps. Posterior 



EXTREMITY OE MALE. 



j/2omnn. 



Fig. 244.— Filaria scapiceps. Spicules. 



with semielliptical alae (fig. 243), the terminal portion bearing lat- 

 erally five pairs of stalked pyriform papillae, which decrease in size 

 posteriorly to the last. There appear to be also two pairs of sessile 

 papillae, one pair preanal and one pair postanal, near the cloacal aper- 

 ture. Three pairs of papillae are prenanal and two pairs are post- 

 anal. The left spicule (fig. 244) is 115 to 135 /x long and appears to 

 be cylindrical anteriorl}^ and flattened posteriorly and bent at the 



