17Q(S.S.472) 



THE MONONCHS 



KM 



39. M. polonicus Stefanski. Two minute teeth are found at the base of the 

 buccal cavity. The conoid tail is somewhat arcuate from the raised anus, and ends 

 in a truncated spinneret one-fourth as wide as its base. The three caudal glands 

 are located in a tandem series in the anterior third of the tail. 



Description derived from young specimens found in vegetable detritus in the 

 Czarna River, Poland. Said by its author to resemble the next species, No. 40. 



40. M. minor Cobb. There are 2 minute, submedian onchi, easily overlooked. 

 Amphids, only one-sixth as wide as the corresponding portion of the head, are 



2.3 7.5 26. eo*"> 96.7 present opposite the 



274 275 27& 371 2~7T^ """ apex of the dorsal 

 tooth, and consist of arcuate, refractive markings hav- 

 ing their convex side toward the lips. They appear to 

 be about one-fourth as wide as the corresponding por- 

 tion of the head. There are excessively minute striae or 

 dentations of the inner surface of the margins of the 

 lips; these structures are so fine that they might easily 

 escape observation much finer than tne rasp-like teeth 

 of the pharynx. The lining of the oesophagus occupies 

 nearly one-third of the optical longitudinal section. The 

 cells of the intestine contain small, somewhat uniform. 



rather evenly distributed granules. The anus is slightly raised, the anterior lip 

 being a little more pronounced than the posterior. The conoid tail is rather 

 strongly arcuate, or even more or less bent near the middle. The comparatively 

 well developed spinneret is one-third as wide as the base of the tail, and pos- 

 sesses a valve similar to that found in Mononchulus. The caudal glands are 

 located opposite to, or a little behind the rectum. The lateral fields are two- 

 fifths as wide as the body. 



This is a cosmopolitan species, found in tropical and temperate regions. It closely 

 resembles M. brachyuris of Biitschli, but is smaller and differs somewhat both in 

 the structure of the tail and in that of the pharynx. Osmic acid to water. Fig. 53. 

 41. M. brevicaudatus, n. sp. Walls of the pharynx unusually thick. Two ex- 

 ceedingly small, ventrally submedian onchi, opposite the middle of the dorsal onchus. 

 2.7 9.3 32. >69' 18 96. Lining of the cesoph- 



2.2 2.7 3.1 3.4 2.2 l ' 5 Bl11 agus prominent, oc- 

 cupying one-third of the optical section. Intestine 6 to 8 

 cells in girth, faintly tessellated. Contour of the tail like 

 that of the head of a duck whose beak is very short; from 

 the anus onward having roughly an equilateral contour. 

 Spinneret more elaborate than usual. The ceratinized 

 walls of the vagina are plainly visible. The elongated 

 eggs are two to two and one-half times as long as the 

 body is wide. The ovaries taper but little. About a dozen 

 females have been examined. No males have been seen. 

 Sperm has been seen at the flexure in the ovaries. The 

 species is probably syngonic. 



Found about the roots of plants in a cranberry bog, New 

 Jersey, U. S. A. Resembles micrurus and brachyuris in its general form, but 

 differs in the details of the pharynx and in those of the tail. The species is nema- 

 tivorous, and also feeds upon rotifers. Sublimate to balsam. Fig. 54, in which, as 

 m many of the original illustrations used in this chapter, what at first sight appear 

 to be merely lines used as shading, are in reality carefully charted striae or lamina- 

 tions of the wall of the pharynx. 



