May 17,1924 
A New Nematode 
669 
4. Internal leaf crown elements extremely large—-Cylicodontophorus. 
Internal leaf crown elements small_5. 
5. Internal leaf crown elements originate at some distance behind anterior 
margin of the mouth capsule_ Cylicostomum sensu stricto. 
Internal leaf crown elements originate close to anterior margin_6. 
6. Mouth capsule with hoop-like thickening at posterior margin. Trichonema. 
No hoop-like thickening----7. 
7. Mouth capsule outline mostly rectangular or trapezium-shaped in lateral 
or dorso-ventral view; posterior end of female mostly straight. 
Cylicostephanus. 
Cylicotoichus. 
Males 4.3-6 mm., females 4.5-6.5 mm. long; dorsal and ventral walls of 
mouth capsule 32/i, lateral walls 22fx high; external leaf crown consists 
of 18 unusually long pointed leaves; dorsal lobe of male bursa of medium 
length; tail of female very short and finely pointed; only one type species. 
C. montgomeryi.. 
Cylicobrachytus. 
1. Male 11.5, female 13.5 mm. long; external leaf crown consists of 45 slender 
elements; oesophagus comparatively short (in female 635/*). 
C. brevicapsulatum . 
2. Females only described, 10-11.5 mm. long; external leaf crown consists of 
24-26 broad-based elements; oesophagus long (800-935/*); type of genus. 
C. prionodes. 
Cylicocercus. 
1. Genital cone very long (about 664/*); elements of external leaf crown num¬ 
ber about 48 _ C. mettami. 
Genital cone not elongated; elements of external leaf crown number not 
over 30_2. 
2. Three triangular teeth projecting into mouth capsule from walls of oeso¬ 
phageal funnel_3. 
No teeth projecting into mouth capsule_ 4. 
3. Appendages of genital cone absent, but posterior part of collar bears two 
sharply pointed processes directed toward each other_ C. tridentatum. 
Appendages of genital cone present as thin, delicate plates, with two slender, 
finger-like processes_ C. goldi. 
4. Median lobe of bursa fairly long; elements of the external leaf crown very 
slightly if at all projecting out of mouth opening_ C. alveatum . 
Median lobe of bursa extremely short, almost semicircular; elements of 
leaf crown clearly projecting out of mouth opening_5. 
5. Walls of mouth capsule (ventral view) have convex outer surface; inner 
surface undulating to give two notches, the posterior, which is the deeper, 
being the site of insertion of inner leaf crown; appendages of genital cone 
consist of slight elevations, with three conical processes, the innermost 
bearing a delicate finger-like projection_ C. pater alum. 
Walls of mouth capsule (ventral view) curve concavely on outer surface, 
convexly on inner; appendages do not have three conical processes_6. 
6. Appendages of genital cone moderately long, outer edges notched, ends 
rounded; no elongate or digitate processes_ C. catinatum . 
Elongate or digitate processes on appendages of genital cone_7. 
7. Each appendage consists of two long, slender, finger-like processes, each 
with a short projection on its inner surface and with a short projection 
on each side between the two processes_ C. catinatum var. literaureum. 
Each appendage consists of a slight elevation, with two simple, unbranched 
conical processes- C. pseudo catinatum. 
