606 
| Ih ante- | Length anal | Ratio 
Cafe NB | vn er OE aber En @) 
in mm. (1) | (2) | (1) 
ed 3 4.54 4.16 | 0.38 0.09 
37 > 5.03 4.62 0.41 0.09 
42 > 3.13 2.77 0.36 0.13 
42 » 3.67 3.31 0.36 0.11 
42 > 3.8 3.4 0.4 0.12 
42 3 4.24 3.81 0.43 0.11 
37 9 4.6 3.8 0.8 0.21 
37 A 6.11 jn 1.11 0.24 
37 » 9.05 1.6 1.45 0.19 
37 > 10.7 8.8 1.9 0.22 
42 > 2.8 2.22 0.61 0.27 
42 > 3.67 B 0.6 0.20 
42 > 5.01 — 0.91 0.22 
42 » | 6.14 5.— 1.14 0.23 
(catch N°. 42) and + 75 u (eatch N°. 37). So the breadth of the rings 
increases with the age of the larvae. However, after moulting, the 
rings of the young Ovyuris-specimens are much narrower. 
The mouth-opening, situated terminally, is round (fig. 4a) and 
not hexagonal as is the case in adult specimens. According to Rarr- 
LET and Henry the mouth-margin is divided into twelve lobes. 
However, this could not be ascertained by us. The mouth-opening 
opens into a very short mouth-cavity (fig. 3). Behind the latter lies 
the pharynx (according to Martini’s nomenclature (1916), generally 
called oesophagus). In imaginal specimens (fig. 5) we can distinguish 
a corpus, an isthmus and a bulbus in the pharynx, according to 
Martini. In the larvae, the pharynx is still short and consists of two 
parts, which can be compared to the corpus and bulbus of the adult 
worm, as. will be evident from the following. 
The corpus pharyngis is about half cylindrical in shape in optical 
section (fig. 3, c.ph.w.). If we look at the pharynx in the direction 
of the longitudinal axis (fig. 4), we see that the corpus is triangular, 
the wall being bent inwards dorso-medially and latero-ventrally (fig. 
4,5). In the anterior part of the pharynx the lumen widens dorso- 
