Genus Cyathostomum Molin, 1861 Hartwich, 1986
Key to species
| 1 | a. Junction of support (S) for ELC and wall of buccal capsule (BC) marked by narrow constriction | 2 |
| b. Junction of S and BC without narrow constriction | 4 | |
| 2 | a. S nearly as large as wall of BC | C. tetracanthum |
| b. S much smaller than wall of BC | 3 | |
| 3 | a. Elements of internal leaf-crown (ILC) inserted on medial wall of BC in sinuous line in lateral view | C. pateratum |
| b. ILC inserted in convex line laterally | C. catinatum | |
| 4 | a. S and wall of BC much shorter laterally than dorsally and ventrally; ILC inserted at ½ depth of BC | C. montgomeryi |
| b. S and wall of BC of similar height laterally, dorsally and ventrally; ILC inserted at 1/5 of depth of BC | C. alveatum |
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© (contents) R.J.
Lichtenfels, V.A. Kharchenko,
G.M. Dvojnos 2003
Design and programming: Yuriy Kuzmin,
2003