15 
and SOm, respectively, from the tip of the tail; in two other specimens 
it is lOlyw and 128/^ respectively, from the tip. The anus is a trans- 
verse slit about 14 to 56 m in transverse diameter. 
At the apex of the tail, there is a small conical projection, 8 to 13.4yw 
long, l.lyw in diameter: this may be curved slightly dorsad and is not 
equally prominent in all specimens. 
Cuticle. — The cuticle at the anterior portion of the body is not so 
thick (about 3/t) as that (about 4 to 6m) over the greater part of the 
worm (measurements taken from sections and also from worms). In 
general it shows no transverse striation: at the tail, however, quite a 
distinct but line striation is visible in the postanal portion and in one 
Fig. 6. — Enlarged transverse section of body through midgut region. Note the follorving details: 
The cuticle appears in two layers and presents four distinct thickenings, two near each lateral 
line; the subcuticula is visible between the cuticle and the muscles; the narrow dorsal and ven- 
tral median bands extend into the body cavity beyond the muscle layer and then increase in 
breadth; the division of the lateral bands into a dorsal and a ventral half is very distinct; near 
the cuticle, in the space between them, is seen a nucleus; nuclei are also visihle in each half near 
the cuticle; the four muscular fields and the centripetal reticulum are very evident; the intestine 
is compressed dorsoventrally, and presents a high columnar epithelium ^vith centrifugal nuclei 
and centripetal cuticular lining; between the lateral bands and the intestine is seen, each side, 
a section of the excretory gland, with its central canal. 
specimen these stride may be followed cephalad to the plane of juncture 
of the rectum with the chyle intestine; some of the specimens also 
show a transverse striation in the esophageal region, but this is prob- 
ably a pseudostriation, as it is not constant and as it is most prominent 
on one specimen in which the head is rather strongly curved. 
