Ascaridæ.

Strongylidæ.

Trichinidæ.

Filaridæ.

Mermithidæ.

Anguillulidæ.

II. Gordioidea.

III. Chætosomoidea.

[154] The ova of Anguillula aceti are stated by Hallez to undergo a similar development to those of Cucullanus.

[155] The following facts are mainly derived from Leuckart’s exhaustive treatise (No. [388]).