The largest male measures 72 mm. in length and at 

 thickest level (about the posterior third) 1.5 mm. in diameter. 

 Anterior end as in female. Tail rigidly incurved, and at 

 level of cloaca narrowed to 0.4 mm. in diameter, from 

 which level it becomes bluntly rounded with a small 

 acutely conical tip projecting 0.25 mm. beyond and curved 

 dorsally, giving an ungulate appearance to the end of 

 the tail (Figs. 6 and 7). Cloaca 0.15 mm. anterior to 

 level of truncation. Genital spicules double, equal, curved, 

 brownish, 1.3 mm. in length. Details of caudal papillae 

 determined with difficulty because of the rigid curving of 

 the tail and the opacity of the specimens. On the small 

 conical tip there are two pairs, No. ] at posterior third of tip; 

 No. 2 at anterior third of tip; No. 3 close to level of truncation, 

 large and conical; No. 4 conical and smaller than No. 3, 

 at level of cloaca; anterior to cloaca five or more pairs of 

 smaller papilla 1 , more widely separated than Nos. 3 and 4. 



Compared with Ascaris serpentidus, Rudolphi, these 

 worms present many common features, and were at first 

 regarded as probably identical. They differ however, very 

 clearly in a number of characters. Among other points the 

 absence of alar cuticular expansions at the anterior end, the 

 more marked division or lobulation of the paired lobes of 

 the pulp of the lips, the broader anterior margin of the lips, 

 the smaller size and more spherical shape of the ova seem 

 sufficient justification for regarding the worms in hand as of 

 separate species. Differentiation from Linstow's Ascaris 

 reticulata from Ardea crocoi (Mith. aus d. Zodl. Samml. f. 

 Naturk. in Berlin, i, heft 2, p. 7) is readily made by the 

 absence of interlabia and denticulationof the lips in the latter, 

 as well as by other striking differences. 



Oxyuris microtyphlon, n. s. (Plate VII). 



Rudolphi (Synopsis, p. 285; No. 45) originally described 

 under the name Ascaris megafyphlon certain small nematode 



