670 
Journal of Agricultural Research 
Vol. XXVIII, No. 7 
Cylicodontophorus. 
1. Internal leaf-crown possesses dissimilar elements, 12 of the 46 elements being 
enlarged and projecting farther than those of the external leaf crown. 
C. ultrajectinum. 
All elements of internal leaf crown similar_2. 
2. Dorsal gutter projects into mouth capsule, almost to its anterior border; 
median lobe of bursa elongated, triangular_ C, bicoronatum . 
No dorsal gutter; median lobe of bursa of moderate size_3. 
3. Female 14 mm., male 9-10 mm.; outer leaf crown 60, inner 40-46 elements; 
posterior end of female suddenly falls away behind the anus to form a 
short tail; genital cone of male small- C. ihlei . 
Female 6-8, male 6-7 mm.; outer leaf crown 40, inner 30-34 elements; 
posterior end of female tapers very gradually to a point, the axis always 
remaining the same as that of body; genital cone of male relatively 
enormous_-_-_C. euproctus . 
Cylicostomum sensu stricto. 
1. Dorsal oesophageal gutter does not extend along wall of mouth capsule—2. 
Dorsal oesphageal gutter does extend along wall of mouth capsule-3. 
2. Mouth capsule short (17-18m), wider than long, walls of moderate thick¬ 
ness; median lobe of bursa short and pointed-C. labratum. 
Mouth capsule fairly deep (33m, Ihle says 37-41m), longer than wide, walls 
remarkably thick; median lobe of bursa long and slender, its sides almost 
parallel_*__ C . coronatum . 
3. Walls of mouth capsule converge from before backwards, are irregular of 
outline, kneed at least twice on both inner and outer surface. 
C. aegyptiacum. 
Walls straight; outline not as irregular as above-4. 
4. Females 12-12.5, males 10-11 mm. long; internal leaf crown of 70-80 ele¬ 
ments; median lobe of bursa long and slender- C. sagittatum. 
Females not over 11, males not over 9 mm.; internal leaf crown of not more 
than 50 elements; median lobe of bursa short---5. 
5. Elements of external leaf crown project A their height; dorsal oesophageal 
gutter extends A depth of capsule; lateral prominences of posterior 
extremity of female well developed- C. ornatum. 
Elements of external leaf crown only very slightly projecting; dorsal gutter 
forms short, blunt tubercle on floor of capsule; lateral prominences of 
posterior extremity of female not well developed-6. 
6. Appendages of male genital cone absent, replaced by two pointed promi¬ 
nences on posterior part of dermal collar; distance from vulva to anus of 
female 150m _C. labiatum. 
Dermal collar of male has prominences like those of C. labiatum , but the 
posterior part of genital cone also has finger-like processes on both sides, 
varying in number and form; distance from vulva to anus of female 95m. 
C. labiatum var. digitatum . 
Trichonema. 
1. Males 16-17 mm., females up to 26 mm.; mouth collar strongly enlarged 
in lateral sectors, relatively low in dorsal and ventral sectors; excretory 
pore posterior to origin of intestine by a distance equivalent to half the 
length of the oesophagus_ T. auriculatum. 
Males not over 14 mm.; females not over 17 mm.; mouth collar of approxi¬ 
mately the same height in all sectors; excretory pore either at junction 
or anterior to junction of oesophagus and intestine-2. 
2. External leaf crown elements short and flat, their free extremities rounded 
and not extending to the anterior margin of the collar- T . radiatum . 
