The external and internal anatomy of the mature larva of Chlorops tœniopus are described in detail.

The external anatomy of the first and second larval instars is compared with that of the third instar and points of difference noted. The puparium and the egg are also described.

The external anatomy of the third larval instar and the puparium of Meromyza nigriventris and of Balioptera combinata are described and compared with the corresponding stages of Chlorops tœnaiopus.

The winter host-plants of the three species are given, together with a list of eleven grasses which have been examined but do not serve as winter hosts for any of the above species.