Belongs within: Microphalloidea.
The Microphallidae are small flukes parasitic on birds (Dawes 1956).
Characters (Dawes 1956): Small or very small distomes, mostly pyriform, having small suckers and a short gut, with caeca scarcely reaching back to level of ventral sucker. Testes at a distance from posterior extremity. Genital ducts with pars prostatica and seminal vesicle situated in front of ventral sucker. Uterus having descending and ascending limbs, forming folds far behind region of testes. Receptaculum seminis absent. Hosts birds. Location gut, sometimes gall bladder. Cercariae xiphidiocercariae.
<==Microphallidae [Microphallinae]
|--Gynaecotyla Yamaguti 1939 [incl. Cornucopula Rankin 1939]D56
|--Spelophallus Jägerskiöld 1908D56
| `--S. primas Jägerskiöld 1908D56
|--Levinseniella Stiles & Hassall in Ward 1901 [=Levinsenia Stossich 1899 non Mesnil 1897]D56
| |--*L. brachysoma (Creplin 1837)O05, D56 [=Distoma brachysomumD56, *Levinsenia brachysomumO05]
| |--L. macrophallos (Linstow 1875) [=Distoma macrophallos, Levinsenia macrophallos]D56
| |--L. pellucida Jägerskiöld 1907D56
| `--L. propinqua Jägerskiöld 1907D56
|--Spelotrema Jägerskiöld 1901D56
| |--S. brevicaeca (Africa & Garcia 1935)D56
| |--S. claviforme (Brandes 1888) [=Distoma claviforme, Lecithodendrium claviforme, Levinsenia claviforme]D56
| |--S. excellens Nicoll 1907 [incl. S. feriatum Nicoll 1907]D56
| |--S. nicolli Cable & Hunninen 1938D56
| |--S. papillorobusta Rankin 1940D56
| |--S. pygmaeum (Levinsen 1881) [=Distoma pygmaeum, Levinsenia pygmaea, Levinsenia pygmaeum, Levinseniella pygmaea]D56
| `--S. simile (Jägerskiöld 1900) [=Levinsenia pygmaea var. simile, L. similis]D56
`--MicrophallusOC03
| i. s.: *M. opacus Ward 1894O05, S75 [=Distomum opacumO05]
| M. minutus Johnston 1948M58
|--M. primasOC03
`--+--M. fusiformisOC03
`--MaritrematinaeD56
|--Maritreminoides Rankin 1939D56
| |--*M. nettae [=Maritrema nettae]D56
| |--M. mediumD56
| `--M. obstipumD56
`--Maritrema Nicoll 1907OC03, D56 [incl. Streptovitella Swales 1933D56]
|--M. arenaria Hadley & Castle 1940D56
|--M. eroliae Yamaguti 1939D56
|--M. gratiosum Nicoll 1907D56
|--M. humile Nicoll 1907D56
|--M. lepidum Nicoll 1907D56
|--M. linguilla Jägerskiöld 1908D56
|--M. oocystaOC03
|--M. ovata Rankin 1939D56
|--M. sachalinicum Schumakowitsch 1932D56
`--M. subdolum Jägerskiöld 1908D56
*Type species of generic name indicated
References
[D56] Dawes, B. 1956. The Trematoda with special reference to British and other European forms 2nd ed. University Press: Cambridge.
[M58] Mackerras, M. J. 1958. Catalogue of Australian mammals and their recorded internal parasites. I–IV. Proceedings of the Linnean Society of New South Wales 83 (2): 101–160.
[O05] Odhner, T. 1905. Die Trematoden des arktischen Gebietes. In: Römer, F., & F. Schaudinn (eds) Fauna Arctica. Eine Zusammenstellun der arktischen Tierformen, mit besonder Berücksichtigung des Spitzbergen-Gebietes auf Grund der Ergebnisse der Deutschen Expedition in das Nördliche Eismeer im Jahre 1898 vol. 4 pp. 289–372. Gustav Fischer: Jena.
[OC03] Olson, P. D., T. H. Cribb, V. V. Tkach, R. A. Bray & D. T. J. Littlewood. 2003. Phylogeny and classification of the Digenea (Platyhelminthes: Trematoda). International Journal for Parasitology 33: 733–755.
[S75] Stunkard, H. W. 1975. Life-histories and systematics of parasitic flatworms. Systematic Zoology 24 (3): 378–385.