BUNONEMA IMPAR HI 



thickened dexter cuticle, and is a little larger. Slightly in front of the anus, 

 and near the median line, both on the left and on the right, there is a papilla (s), 

 that on the right being a little the larger, and not quite so near the median line, 

 but still outside the dexter cuticle. A little behind the middle of the tail there 

 is a submedian pair (<;), of which the right hand one is in the edge of the thick- 

 ened dexter cuticle, while the left hand one is very inconspicuous and somewhat 

 farther forward. Considerably farther back there is a group of about eight 

 papillae, (w, x, y), arranged in four pairs, some of which are exceedingly obscure. 

 The anterior pair, (w), is ventrally submedian. This pair is followed by two dor- 

 sally submedian pairs, (x), nearly opposite to which is a ventral pair, (y), one 

 nearly in front of the other. It will be noted that these supplementary organs 

 are arranged much as in some species of Cephalobus. 



The ejaculatory duct is about two-fifths as wide as the body. It has the 

 same width as the single testis, whose reflexed blind end is located not far behind 

 the base of the oesophagus, and extends backward a distance about equal to the 

 length of the body diameter. 



Habitat. Found in the rotting wood of red oak, Washington, D. C., by Dr. 

 Howard Crawley. 



5.3 18. 26. 'M58. 90. 



2. Bunonema impar, n. sp. sTs <U <Ti T! si ' 32 mm ' On the right hand 

 side there are two rows of yellowish tubercles, each row consisting of about 

 eighteen to twenty members. The lip region bears a somewhat thumb-shaped 

 lateral, more or less forward-pointing, protuberance which is probably homolo- 

 gous with the dextral tubercles. Opposite the base of the pharynx is a single 

 tubercle, the first genuine pair of the lateral series being a little in front of the 

 median bulb; thence backward all the tubercles are in somewhat irregular pairs, 

 except one or two of those near the tail end. The members of each pair are placed 

 side by side. These tubercles are rounded elevations having a height about 

 equal to the width of eight of the annules of the cuticle. When the nematode is 

 in a straightened-out attitude the distance between the pairs of tubercles is 

 about equal to their width. The posterior tubercles tend to run together, and 

 are slightly lower and flatter than the anterior. The anterior tubercles, especi- 

 ally those on the neck, are capped with slightly thickened, rather uniform chitin, 

 which bears extremely minute markings similar to those noted on Bunonema 

 inequale. The face of the tubercles appears punctate, though on focusing deeper 

 they appear striated. The lip region is very similar to that of Bunonema inequale. 

 The largest setae are of about the same size and proportions as in inequale, as 

 are also the ventrally submedian setae, though the latter are hardly inclined to 

 be inflated at the base. Between the papillae there seem to be structures very 

 similar to those of inequale. When seen from the right side the adjacent lip region 

 presents the following appearances: the two setae with saccate bases appear to 

 be nearly at right angles to each other, and have their tips located at a distance 

 from each other equal to the length of the pharynx. Each of these setae is about 

 three-fourths as long as the chitinous portion of the pharynx. Between these 

 two setae is the very pronounced, concave-conoid, blunt, rather forward-point- 

 ing, almost thumb-shaped protuberance already mentioned, which is probably 

 homologous with the lateral tubercles, though it presents little or none of the 

 brownish or yellowish coloration characteristic of the tubercles. On each side 



