May 17,1924 
A New Nematode 
671 
External leaf crown elements not short and flat, their free extremities 
pointed and extending to or beyond the anterior margin of the collar. 3. 
3. Dorsal gutter present_ 4. 
Dorsal gutter not present_ 6. 
4. Internal leaf crown elements (52 in number) quite large and broad; dorsal 
gutter short, just extending above base of capsule; prebursal papillae 
very long (250m) ___ T. adersi. 
Internal leaf crown elements minute plates; dorsal gutter well developed, 
terminating about midway between anterior and posterior margin of 
capsule; prebursal papillae short (not more than 70m)-5. 
5. Males 8-10 mm.; females 9-14 mm; accessory rays of bursa vary. 
T. nassatum. 
Males 6.5-7.5, females 8.2-9.7; median dorsal ray of bursa has constant 
accessory side branch_ C. nassatum var. parvum. 
6. Excretory pore at junction of oesophagus and intestine- T. tetracanthum. 
Excretory pore anterior to junction of oesophagus and intestine- 7. 
7. Males 6, females 7-9 mm.; external leaf crown consists of 20-24 elements; 
buccal capsule 27 m deep; distance between anus and vulva 81 m« 
T. leptostomum. 
Males 12.3-13, females 12.3-17 mm.; external leaf crown consists of 30 or 
more elements; buccal capsule 38m or more deep; distance between anus 
and vulva 180m or more_ 8. 
8. Males and females 12.3 mm.; external leaf crown elements project only 
very slightly from mouth opening and their free extremities are drawn 
in toward each other; median lobe of bursa of medium length (posterior 
ray 635m) and fairly broad__ T. triramosum . 
Males 13, females 17 mm.; external leaf crown elements project consider¬ 
ably out of mouth opening and curve outward; median lobe of bursa 
long (posterior ray 847m or more)_ 9. 
9. Posterior ray of median lobe of bursa about 847m - T. elongatum. 
Posterior ray of median lobe of bursa about 1.5 mm. 
T. elongatum var. kotlani. 
Cylicostephanus. 
1. External leaf crown consists of not more than 8 elements; dorsal gutter 
extends along the mouth capsule almost to anterior margin-2. 
External leaf crown consists of from 14-35 elements; dorsal gutter projects 
only slightly or not at all along mouth capsule_3. 
2. Males 6-6.5, females 8 mm. long; oesophagus shows well-marked, ring-like 
enlargement at its anterior end; median lobe of bursa narrow and long 
(dorsal ray about 525m); posterior extremity of female straight. 
C. calicatum. 
Males 4-4.6 mm., females 4.1-5.6 mm. long; oesophagus does not show 
ring-like enlargement at anterior end; median lobe of bursa broad and 
short (dorsal ray 140-198m); posterior extremity of female usually has 
S-shaped bend_ C. minutum. 
3. Mouth capsule very deep (about 70m) ; external leaf crown consists of about 
35 elements; oesophagus very long (about 0.8 mm.), tail of female long 
(anus 0.3 mm. from tip)_ C. poculatum. 
Mouth capsule comparatively shallow (17-32m); external leaf crown con¬ 
sists of 14-18 elements; oesophagus not elongated (0.2 to 0.4 mm.); tail 
of female comparatively short (anus 0.05-0.1 mm. from tip)_4. 
4. Males 4.8-5.5 mm., females 4.7-5.7 mm. long; dorsal lobe of male bursa 
narrow, tapering and very long; anus of female 95-1 24m from tip of 
tail_ C. lorigihursatum. 
Males 9-9.5 mm., females 10-10.5 mm. long; dorsal lobe of male bursa 
short and broad; anus of female 56m from tip of tail_ C. hybridum. 
