86 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 50. 



Fig. 100.— Oxtueis stroma. 

 Head viewed from the 

 FRONT. Enlarged. Af- 

 ter VON LmSTOW, 1885. 



elevation bears a single papilla and the other elevations bear a double 

 papilla. 



Male 1.5 mm. long and 160 \k thick. The 

 esophagus is 2/9 of the total length. The spic- 

 ule is straight and is 79 jjl long (fig. 101). The 

 accessory piece has a hooked point and is 3G ^ 

 long. The cloacal aperture is 2/31 of the total 

 length from the posterior end of the body. 

 There is one pair of large postanal papillae. 

 Anterior of the cloacal aperture are two cuticu- 

 lar bullae, and anterior of these are three pecul- 

 iar large projecting pads, of which the most 

 anterior is in the median portion of the body. 

 Female 4.6 mm. long and 360 [x thick. The 

 esophagus is 1/10.7 of the total body length. The anus is 1/7 of 

 the body length from the posterior extremity. The vulva is 4/15 

 of the body length from the anterior extremity. The eggs 

 are 130 to 140 [l long and 43 [i thick. They 

 have a double Avail, the outer wall being marked 

 with circular depressions showing a dark spot in 

 the middle (fig. 102). The contained embryos 

 have a strongly developed esophagus with a bulb 

 bearing teeth and terminate in a rounded tail with 

 no appendage. 



Life history. — The embryos develop in the 

 cecum, where von Linstow 

 has found about 100 im- 

 mature specimens 580 to 

 640 [X long and 49 to 54 \!. 

 thick. The esophagus in 

 these measured 1/6.2 and 

 the tail 1/7.1 of the total 

 length. 



Host. — Apodemus sylva- 

 ticus (Mus sylvaticus). 



Location. — Small intes- 

 tine; immature forms in 

 the cecum. 



Locality. — Not given. 

 Seurat (1916) says this is O. ohvelata. See Addendum, page 224. 



Fig. 101.— Oxyuris stroma. 

 Posterior extremity of 

 male. Enlarged. Af- 

 ter von Linstow, 1884. 



FlO. 102.— OSYURIS 



STROMA. Egg. 

 Enlarged. After 

 VON Linstow, 1885. 



OXYURIS TETRAPTERA (Nitzsch, 1821) von Linstow, 18780. 



Synonyms. — Ascarls dipodis Rudolphi, 1819, of Stossich, 1898; 

 Ascaris tetraptera Nitzsch, 1821 : Oxyuris semilanceolata Molin, 



