212 JOURNAL OF THE WASHINGTON ACADEMY OF SCIENCES VOL. 13, No. 10 
constriction so that it constitutes a sort of cap on the 
front of the head. This somewhat quadrate cap is longitudi- 
nally faintly six-lobed and each lobe is again longitudinally 
as well as transversely subdivided. See Fig. 2. The lip 
region of the male is like that of the female except that 
it is more nearly hemispheroid, that is, relatively higher 
and slightly larger. There is a rather robust six-ribbed, 
yellowish, dome-like structure as the framework of the lip- 
region, through it is obscured by the nature of the cuticular 
covering. This framework extends a little back of the 
labial constriction and its yellow color becomes more evi- 
dent here. See Fig. 3. Needless to say, therefore, the 
amalgamated lips are fixed, and shut closely around the 
anterior extremity of the onchium. Whether the lip region 
ae Hs Setaibels | Nepere rece yy but no raat es have 
— <4 een seen. e tylenchoid pharynx is of a very robust na- 
Miia \thsiaon x500 tre and reminiscent of that of Nemonchus. The base of 
Fie, 2. An obligue the onchium, or spear, thirteen microns wide by ten high, is 
arr ome tne e very distinctly three bulbed and is about one-fifth as wide as 
ae Ae EN a the corresponding portion of the head. Each of the three — 
nature of the cap is bulbs 7s anteriorly somewhat ‘lobed,’ presenting sometimes 
shown in the front view, two and sometimes three rather distinct forward pointing 
pei eben knobs. Owing to its index of refraction this lobed base of 
the onchium, as well as the “hilt,” are almost totally invisible in balsam mounts; 
while the acute tapering anterior part remains distinctly visible,—another 
evidence of the two-fold character (and origin) of the tylenchoid onchium. 
The posterior attachment of the musculature comprising the ellipsoidal 
pharyngeal bulb, which is one-half as wide as the head, is not only to the front 
portion of the bulbs of the onchium but also to their posterior surfaces. The 
hilt is about half as wide as the bulbous base; the anterior end of the spear is 
blunt, and the lumen relatively unusually narrow ;—all which makes the spear 
an unusually substantial structure, capable of puncturing tissues offering con- 
siderable resistance. In harmony with this, the ellipsoidal to obpyriform 
spear guide is of strong construction, consisting in part of six outwardly bowed 
elastic elements surrounding the anterior third of the spear and springing back- 
ward from the base of the cutinized lip region. (Figs.2and3.) This six-fold 
spear guide has a variable length and width, its form changing with the atti- 
tude of the spear ;—when at rest, with a length of fourteen microns, its width 
is about eight microns,—that is, it is about one-third as wide as the correspond- 
ing portion of the head. In addition to this spear guide the cutinized lip- 
region fits closely around the anterior portion of the spear for a considerable 
distance. Both the spear and the spear guide appear to present traces 
of transverse striation corresponding in fineness with the minute subdivisions 
of the annules sometimes visible in the subcuticle. The two parts of the 
spear are rather distinctly set off from each other by a very fine transverse 
junction mark, as in many T'ylenchi. No amphids, deirids or phasmids have 
been seen. There are no eyespots. The oesophagus is tylenchoid, presenting 
however, as already indicated, a rather distinct pharyngeal bulb, something 
rather uncommon in the T'ylenchidae. The spherical or oblate median oeso- 
phageal bulb is half as wide as the corresponding portion of the neck, and is set 
off both fore and aft from the remaining narrow portions of the oesophagus,— 
very abruptly behind and rather abruptly in front. Behind the median bulb 
the narrow oesophagus gradually enlarges to form a rather obscure posterior 
ae 
