498 



FRESH-WATER BIOLOGY 



54 (53) Male supplementary organs protusile tubes. Aphanolaimus de Man. 



Genus of fresh-water nematodes, 

 of which nearly a dozen species are 

 known. Hermaphroditism occurs. 



Representative species. 



Aphanolaimus spiriferus 

 Cobb 1914. 



•5ff« 

 ■3.1' 



55 (52) 



Viviparous. Two embryos and de- 

 veloping egg have been seen in each 

 uterus at the same time. Eggs, 

 about as long as body is wide, and 

 less than half as wide as long. 



Habitat: Potomac River, Wash- 

 ington, D. C. 



Fig. 801. Aphanolaimus spiriferus. 

 I, lateral view, anterior end of female; 



II, lateral view, posterior end of female; 



III, lateral view of head, more highly 

 magnified; IV, male supplementary 

 organ; V, lateral view of posterior ex- 

 tremity of male. 



a, mouth opening; b, amphid; c, lumen 

 of esophagus; d, pigmented eye-spots (?) ; 

 e, intestine; /, nerve cell; g, rectum; A, 

 nerve-ring; *, anus; k, esophagus; /, cau- 

 dal gland; m, duct of caudal gland; n. 

 glandular body at base of neck; 0, spin- 

 neret: pf ejaculatory duct; g, intestine: r, 

 anterior end of cloaca: s, right spiculuro; 

 t, backward pointing accessoiy piece; «, 

 nerve cells (?); v, male supplementary 

 organs. (After Cobb.) 



Amphids circular or ellipsoidal Tripyla Bastian. 



Genus of toward twenty fresh-water 

 species, some at least carnivorous. 



Representative species. 



Tripyla lata Cobb 1914. 



ir 2.3 3 1 is i.^ }.2 ' 2*™»-' 



J,. 2 '.: ». -M-" M 8 ■ ,. 



P"!! 3:5 r? Ts SVJT^ ^''™°-- 



In lumen of pharynx at a point re- 

 moved from anterior extremity a distance 

 a little greater than radius of head, 

 minute inward-pointing dorsal tooth, 

 having a length about equal to width of 

 one of the annules of cuticula, proving 

 that pharynx extends backward a dis- 

 tance equal to width of head. In some 

 specimens not far behind this point dis- 

 tinct transverse fold in lining of esopha- 

 gus. 



Habitat: Alpine Lakes, Bald 

 Mountain, Colorado. 



Fig. 8c2. Tripyla lata, 

 a, labial papilla: b, lip; c, amphid; d, sper- 

 matozoon; e, spermatocyte of anterior testis; 

 /, base of esophagus, pseudo-bulb; g, nerve- 

 ring; h, cuticula: t, esophagus: j, lining of 

 esophagus; k. intestine; /, posterior testis; 

 m, male supplementary organ; n. vas def- 

 erens; 0, retractor muscle of spiculum; 

 p, right spiculum: g, intestine; r, duct ol 

 caudal gland; s, caudal gland; t, spinneret. 

 (After Cobb.) 



