NO. 2131. NEMATODE PARAf^TTEfi OP RODENTS— HALL. 



—OV. 



\\-'Z,7hi. 



Type-species. — Strongyloides intestinalis (Bp.vay, ut;;;:; 

 1877) Grassi, 187d=^.StrongyIohles stercoraUs (Ba- u'Vi 

 vay, 1876). \WM 



STRONGYLOIDES PAPILLOSUS (Wed!, 1856) Ransom, igiio. 



Synonyrns. — Trlchosomvm papillosum Wedl, 

 1856 ; Rhahdonema longus Grassi and Segre, 1887 ; 

 Strongyloides longus (Grassi and Segre, 1887) 

 Eovelli, 1888«. 



Specific diagnosis. — Strongyloides (p. 6) : Para- 

 sitic generation. — Length 3.5 to 6 mm., thickness 50 

 to 60 [;.. Body (%. 1) filiform, of nearly equal thick- 

 ness throughout most of its length, gradually atten- 

 uated anteriorly to a diameter of about 15 ^. at the 

 head. Posterior end of body (fig. 2) diminished in 

 size backv/ard beginning some distance in front of 

 the anus near the loop of the posterior ovary, then 

 suddenly reduced just behind the anus, and termi- 

 nating in a short slightly tapering tail with rounded 

 tip. Esophagus increases gradually in size poste- 

 riorly, and is 650 to 800 [i, long. Diameter of body at 

 base of esophagus 40 to 50 fx. 

 Anus 55 to 70 jj. from tip of the 

 tail. Diameter of body at anus 

 about 20 ^. Vulva (fig. 3) a trans- 

 verse slit with rather salient lips 

 situated 1.6 to 2 mm. from the 

 posterior end of the body. Eggs 

 ellipsoidal with very thin shells, 

 40 by 20 p. to 60 by 25 ix in diame- 

 ter. Not more than a dozen or 15 

 fully formed eggs present in the 

 two uteri at any one time. Eggs 

 when passed in the feces of the 

 host usually contain vermiform 

 embryos which hatch in a few 

 hours under suitable conditions 

 of temperature. 



Free-living generation. — Male 

 undescribed. FemaJe (fig. 4) 1 to 

 1.2 mm. long by 40 p. in thickness. Esophagus one-tenth to one- 

 seventh of the total length of the body. Vulva with salient lips, near 

 the middle of the body. Tail slender, acutely pointed. Anus about 

 one-tenth of the length of the body from the posterior end. Eggs 

 with thin shell, 65 by 30 [j, in diameter. 



'(LHa, 



Tig. 1.— STRONG-iXOIDES 



PAPILLOSUS. Parasitic 

 adlt.t. *vulva. x 15. 

 After Ransom, 1911. 



Fig. 2.— Strongyloides 

 PAi'iLLosus. Poste- 

 rior END OF BODY OF 

 PARASITIC ADULT. 071., 



Anus; int., intestine; 

 ov., ovary. x 300. 

 After Ransom, 1911. 



