Thelaziidae

Thelaziidae is a family of spirurian nematodes, which form the mid-sized lineage of the superfamily Thelazioidea. Like all nematodes, they have neither a circulatory nor a respiratory system.
They number 7 genera or so, with a few dozen species all together. Mostly parasites of birds, a few have also been found in other vertebrates.

Systematics

The subfamily Oxyspirurinae is monotypic, as are several little-known genera in the Thelaziinae; these all might not be valid. All together, the systematic layout of this family is liable to change and cannot be considered more than tentative.
Subfamily Oxyspirurinae Skrjabin, 1916Oxyspirura Dräsche in Stossich, 1897
Subfamily Thelaziinae Skrjabin, 1915Ceratospira Schneider, 1866Hempelia Vaz, 1937Pancreatonema McVicar & Gibson, 1975Pericyema Railliet, 1925Thelazia Bosc in Blainville, 1819Thylaconema Chandler, 1929