THE MONONCHS 



1. M. exilis, n. sp. The cylindroid neck ends in a rounded head with a dis- 

 tinctly expanded lip region. The large pyriform pharynx is armed with three sub- 

 equal teeth. The wider anterior part of the pharynx is two-thirds as wide as the 

 * head. The apices of the teeth are midway, 



1.8 6.2 27. '78' 15 98.2 the dorsal one being a little the farthest for- 



1.6 1.8 2. 2.3 \. m ward. Amphids somewhat behind the lips, 



1.6 6. 24. -M- 38 98. but farther forward than the teeth, consisting 



1.6' 1.8 2. 2.2 1.2 of somewhat rectangular markings one-fifth 



as wide as the head, longest in the transverse direction, and with the lateral and 

 front margins plainer than the posterior. Lining of the oesophagus not so promi- 

 nent as in most mononchs. Intestine greenish, finely granular, obscurely tessellated. 

 Cardia long and plainly to be seen through the flat, colorless pseudo-bulb at the 

 beginning of the intestine. The rectum has a thick lining of highly refractive 

 ceratin, and is a prominent organ one and one-half times as long as the anal body- 

 diameter. Terminus about one-fourth as wide as the base of the tail. The very 

 broad vulva is only slightly elevated. Posterior sexual branch only two-thirds as 

 long as the anterior. On the male there is a row of about 14 equidistant, rather 

 closely approximated ventral ridges in front of the anus, extending forward a dis- 

 tance equal to 3 tail-lengths. These do not bear any prominet papillae. The body 

 is somewhat thicker in the region of these ridges. Spicula linear, uniformly 5 /j. in 

 diameter when seen in profile, the proximal end being in no way distinguished from 

 the rest of the shaft. The accessory pieces appear to rest rather closely against the 

 distal halves of the spicula. 



Found about the roots of moss, Moss Vale, New South Wales, 1894. Examined 

 in water after fixation with osmic acid. 



2. M. radiatus, n. sp. The 

 amphids of this rather small 



3.3 9. 



30. 



95. 



.8 mir 



2.2 2.8 2.8 2.3 2.2 



but elegant species are minute and inconspicuous, about one- 

 eighth as wide as the corresponding part of the head. The 

 granules of the intestine are largest posteriorly, where they are 

 about one-half as wide as the spinneret. The intestine is not 

 tessellated. The tail is markedly arcuate, its spinneret about 

 one-fifth as wide as its base. Anus very slightly raised. Caudal 

 glands rather small, elongated. Sexual organs apparently double and symmetrically 

 reflexed. 



Description derived from a single young specimen from a cranberry bog in New 

 Jersey, U. S. A. Flemming solution to glycerine. Fig. 17.** 



3. M. palustris, n. sp. Intestine 12 to 15 cells in girth, more or less distinctly 

 "# J 2.7 8. 30. '62' 15 97. tessellated. Tail arc- 



jT 27s 27e 27? 1.9 > 1-4 IBra uate, its rather conoid 

 spinneret about one-fifth as wide as its base. Caudal glands 

 broad and saccate, their ampullae occupying most of the 

 posterior half of the tail. The elongated eggs are about 

 twice as long as the body is wide, and occur one at a time 

 in each uterus. The rather small, tapering ovaries contain 

 8 to 10 ova arranged more or less irregularly. 



From a white cedar swamp, Jefferson County, Wis- 

 consin, U. S. A. Feeds upon rotifers and probably upon 

 other nematodes, which it appears to masticate (page 443, 

 fig. 10). Sublimate to balsam. Fig. 18. 



^* This decimal formula for nemas is explained in the appendix. 



** The species figures have the same magnification throughout, so that the reader may guage the 

 relative sizes. 



