FREE-LIVING NEMATODES 



491 



34 (31) Pharynx cyathiform then prismoid, ending behind very definitely; 



amphids distinct. . Etkmolaimus de Man* 



Genus of two known sf)ccu>s. one Kuroiican one 

 American. Closely relatod to Chromadora. from 

 which It IS readily distinguished by the narrow uniform 

 posterior portion of the pharynx, which is usually 

 surrounded by a comparatively distinct pharyngi-al 

 bulb. 



Representative species. 



Ethmolaimus amerkanus C obb 1Q14. 



[- 



35 (30) 



Labial papillae, apparently 12. Onchus thumb- 

 shaped, forward pointing, attached to a distinctly 

 thickened rib of cuticula which extends from the lip 

 region back to the base of the pharynx, and is thicker 

 anteriorly than posteriorly. Fully dcvdoiR-d ov.i arc 

 nearly twice as long as the body is wide, and one-third 

 as wide as long. Form, size, and number of eggs un- 

 known. 



Habitat: Spring, Washington Country Club, Chevy 

 Chase, Md. 



Fig. 790. Ethmolaimus americanus. Lateral view of a 

 female, a, lips; b, minute dorsal and ventral pharyngeal 

 teeth; c, one of the four cephalic setae; d. amphid: t, 

 pharynx; /, nerve-ring; g, excretory pore; h, nerve cells; 

 i, cardiac bulb; 7", beginning of the intestine; *, rcnclle 

 cell (?); /, beginning of main portion of the inicstinc; m.onc 

 of two pairs of unicellular organs of unknown significance; 

 w, cuticula; 0, one of the cells of the intestine; p. su(x:uticuU; 

 q and r, body cavity; s, vulva; /, nucleus of one of the 

 muscle cells; «, spinneret; v, one of the caudal glands; 

 w, anus. 



Dorsal tooth minute, amphids circular. . . . Mkrolaimus de Man. 



Amphids well developed. 

 Genus of few species from Europe 

 and North .America. 



Representative species. 



Idkrolaimus jhrciatilis 

 Cobb 1914. 





as 

 ii' 



The eggs appear to be deposited be- 

 fore segmeiitatinn begins. Sfxvimens 

 with one, and thn.se with two. (Svarics. 

 appear to be about cnjually numerous; 

 as no other dilTerence has been detected, 

 they are included for the present under 

 the same name and description. 



Habitat: Maple River, .Michigan. 

 Fig. 791. Mkrolaimus ilutidtilis. 



I. lateral view of female; II. head of 

 the same. / u • 



a. mouth opening: b. one ol the six 

 cephalic papillae; c. one of the four cephalic 

 setae; </, one of the small phar>n»:c.il tcrlh; 

 e, excretor\- iwre; /. spiral amphid. f. 

 esophagus; A. ner\-e-nng; 1. car.luc 

 bulb: j. preliminar>- portion ol the in- 

 testine: k. renctte cell; /. bodv i-ivity; 

 m lumen of intc->itinc: w. one of the cclU 

 of the intestine; 0. anus: /. lie mi re in 

 posterior ovar>'; Q. uterus: r. blind rn.l o 

 posterior ovar^-; s, one of the tl.n-r v.uid*! 

 glands; /. spinneret: u, ckk> 

 w, cuticula. 



.Iva: 



(After Cobb.) 



