SUBGENUS MONONCHUS 



labial papillae so far recorded is shown in megalaimus. Biitschli and later authors 

 describe and figure the papillae of truncatus as setose. It seems hardly likely that 

 Bastian would have overlooked setose papillae such as those figured by Biitschli. 

 In that case Bastian's truncatus should be retained as a species, probably having 

 very inconspicuous labial papillae similar to those of megalaimus, while the data 

 given by Biitschli may be taken as establishing a new species, for which the name 

 obtusus is proposed. (See No. 16.) 



Found in a small pool, among decaying moss and liverwort, England. Fig. 31 

 (after Bastian). 



19. M. dadayi Micoletzky. A striking character of this species, "M. macrostoma 

 Bastian var. armatus Daday," as described by its author, is the presence of 6 small, 



? ? 22. ? 86. tooth-like cuticular spines close 



H 1 ? ? ? 4~72 2.6 K6 '" around the mouth. No such 

 structures have been seen in other species, and accordingly 

 Micoletzky has proposed for the form the name dadayi. 



This is a littoral species. The description and drawings 

 rest upon the examination of a single specimen. The original 

 , m description is very brief and the accompanying illustrations, 

 one of which is here reproduced, are meager sketches of the 

 head and tail ends. A more complete examination of further 

 750 specimens is desirable. Fig. 32 (after Daday). 



20. M. longicaudatus Cobb. Opposite the apex of the dorsal tooth there are 

 refractive transverse thickenings of the wall of the pharynx in the ventrally sub- 

 median region, and in front of these thickenings there are a few transverse striae. 

 The lateral fields are two-fifths as wide as the body, and are distinctly to be seen, 

 since they have definite lateral contours, doubtless owing to the thickness of the 

 muscular layer. The lateral fields contain scattered, nearly colorless granules 

 somewhat smaller than those contained in the intestinal cells. In young specimens 

 the vagina is distinctly separated from the uterus by a deep constriction, and the 

 uterus itself is bulbous near this constriction and narrower farther away. Longi- 

 caudatus is a syn- 3. 6.? 26. ^55*23 88. 



gonic species. In 2~! 274 3~l 3~! 2.4 ' 

 the adult and egg-producing specimens the eggs are 

 seldom or never seen more than two at a time, one in 

 each uterus. 



A predacious species, feeding upon other nematodes, 

 upon rotifers and protozoa. It is cosmopolitan, and is 

 found in rivers, ditches and pools, as well as in the 

 soils of swamps and meadows. It occurs, sometimes in 

 vast numbers, in the sand of the slow filter beds of the 

 water-works of cities and towns. Flemming solution 

 to glycerine. Fig. 33 ; also fig. 2, p. 132. 



Longicaudatus suffers from an internal disease caused 

 by a fungus having a branched mycelium. The width 

 of the mycelium is about half as great as the thickness of the body wall of the 

 nema, and the septa oi the cells are separated from each other by a distance equal 

 to the diameter of the body. There are two other diseases affecting this nema, 

 one of microbe origin, the other of fungous origin; they appear, however, to be 

 confined to the cuticle. One consists of short-styled, elongated-ellipsoidal elements 

 on the surface of the body extending outward at right angles. These have been 

 seen on the tail end. The microbe growth appears as a coating, sometimes of 

 considerable thickness, and occurs on various parts of the body. It has been seen 



ff/OW 



