498 



FRESH-WATER BIOLOGY 



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. 



X 



9 



55 (52) 

 i 



-V c 



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; h, 

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

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

 glandular body at base of neck; 0, spin- 

 neret; p, ejaculatory duct; q, intestine; r, 

 anterior end of cloaca; 5, right spiculum; 

 t, backward pointing accessory piece; u, 

 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. 



r ^ I J 7_ 20 '»'*'> 8_5_^ 2^ ^^, 



7. „ .7 7_ 20 -M- 5» 82 8 . , , ^^ 



p ' 2 1 — 3-2 Ji Ts — I?sTr\ ^■*'^' 



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. 802. 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; j, esophagus; j, lining of 

 esophagus; k, intestine; /, posterior testis; 

 w, male supplementary organ; n, vas def- 

 erens; 0, retractor muscle of spiculum; 

 p, right spiculum; q, intestine; r, duct of 

 caudal gland; s, caudal gland; /, spinneret. 

 (After Cobb.) 



