BY H. A. BAYLIS. 313 



described, from immature material, and Ihle (1912) has 

 suggested that it is perhaps identical with 0. apiostonium 

 Willach. From the data obtainable from the present speci- 

 men, however, this would seem not to be the case. This in- 

 dividual has a length of about 17 mm. and a maximum thickness 

 of 0.7 mm., as against 10-2.8 mm. and 0.425-0.565 mm. 

 respectively in the males of 0. apiostomiim, , according to Ihle. 

 The cuticular striations are 0.02 mm. apart (0.016-0.017 mm. 

 in male apiostomu7n) . The cervical groove is at 0.45 mm. 

 from the anterior end (0. 202— 0.27 mm. in male apiostonium) . 

 The mouth-capsule is quite different in shape from that of 

 0. apiostomuni as described by Ihle, being very wide (0.14 

 mm. in outside diameter), with walls that are more or less 

 lenticular in optical section, and 0.037 mm. in length. In 

 apiostomiim, according to Ihle, the capsule measures 0.06— 

 0.082 mm. in width and 0.02-0.021 mm. in length. Three 

 slender, pointed and slightly recurved teeth, one dorsal and 

 two sub ventral, are present near the anterior end of the 

 oesophageal funnel, resembling those of 0. hrumpti as figured 

 by Railliet and Henry (1912), rather than the "pointed 

 nodules" described by Ihle in 0. apiostomiim. The number 

 of elements in the external leaf-crown unfortunately cn,nnot 

 be made out with certainty, owing to the mouth being full of 

 debris. The oesophagus measures 0.94 mm. in length (as 

 against 0.615 mm. in the male of apiostomum), and has 

 a maximum thickness of 0.2 mm. (0.17 mm. in apiostomum). 

 There is nothing worthy of remark in the form of the bursa 

 or in the arrangement of its rays, which seems to be identical 

 with that of apiostomum. The spicules measure about 2 mm. 

 in length. (In apiostomum they are only 1.25-1.35 mm. 

 long.) 



Of the seven other species of Oesophagostomum recorded 

 from Primates, besides 0. apiostovium and 0. ovotmn, several 

 have only been very briefly described, and only two, 0. 

 hrumpti Railliet and Henry and 0. stephanostomum Stossich, 

 are at all well known. In 0. hrumpti the male measures only 

 6.7-11 mm. in length, and the spicules are only 0.9-1.08 

 mm. long. In 0. stephanostomum, according to Railliet and 

 Henry (1912), the male is of about the same size as the speci- 

 men here under discussion (17-22 mm. long), but the spicules 

 measure only 1.38-1.475 mm., the cervical groove is consider- 

 ably nearer (0.36-0.365 mm.) to the anterior end, and the 

 buccal capsule is much shorter (0.022 mm.). 0. hlanchardi 

 RaiUiet and Henry (1912, p. 572, footnote) ; from the Orang- 



