XXIX 
TYLENCHUS ALATUS n. sp. 
By N. A. COBB, Principal Nematologist, U.S. Dept. Agriculture 
74 
5. £2, -19. = M 92.8 
Tylenchus alatus n. sp. 25 oi = 36 35 25 0.53 mm. 
THE moderately thick layers of the transparent, colorless, naked cuticle are 
traversed by three hundred and forty transverse annules, all alike except near the 
head where they are narrower, and only about a micron across; — through most 
of the body they are nearly two microns across. These annules, which are not 
resolvable into secondary elements, are interrupted on the lateral fields by the 
presence of strongly-developed wings (hence the specific name alatus), which 
in the middle of the nema are nearly one-fourth as wide as the body itself. 
These wings, beginning very narrow near the lips and fading out at full width 
near the anus on the male, find optical expression as four longitudinal lines, 
the outer ones being almost as distinctly crenate as the contour of the body; 
the inner ones, however, more nearly straight and much fainter, and about as 
far removed from each other as they are from the crenate ones. No series of 
pores has been seen in the cuticle. Longitudinal ‘‘striae,’’ due to the attach- 
ment of the musculature, are visible in most regions of the body. The contour 
of the nema is very distinctly and beautifully crenate. The neck, which is 
eylindroid posteriorly, becomes convex-conoid anteriorly and ends in a dis- 
tinctly capitate subhemispherical lip region slightly flattened in front and set 
off by constriction. The lip region itself is also very finely crenate in contour, 
the number of very fine diminishing annules (the larger about 0.6 microns) 
comprising the lip region being perhaps about five. The mouth is not de- 
pressed. The amphids, and labial papillae, if any, have not been seen. There 
are no eyespots. In the single specimen under examination— mounted in 
glycerine from a preparation in formalin, — the lip region does not show a six- 
ribbed dome-like framework such as is often seen in triplonchs. Although the 
lip region is very distinctly set off by a constriction, there is no annule at the 
constriction more marked than the others. There is a very well-developed, 
long, typical tylenchoid spear, compassing about eighteen annules, with a dis- 
tinctly three-bulbed base about one-sixth as wide as the corresponding portion 
of the neck. Anteriorly the spear is guided by a rather long, compound appara- 
tus, which finds its optical expression as, (1) parallel elements, a micron apart, 
extending back a little farther than the posterior limits of the lp region and 
probably representing an encircling hollow cylinder one micron in diameter, 
and, (2) slightly outwardly bowed refractive elements about twice as far back 
487 

