ZOOLOGY: W. M. WHEELER \\3 
traces of the basal portions of some of the other veins. Brues^^ distin- 
guishes three classes of vestigial wings among insects: those having 
essentially a pupal character, those essentially normal, except for their 
smaller size and less complex venation and those consisting of httle more 
than a hollow bag, without venation. The wings of M. subapterum 
evidently belong to the second class. 
In six specimens of a pale variety of Monomorium ruhriceps Mayr 
{cinctum var.nov.) taken by Mr. Albert Koebele in Victoria, Austraha, I 
find the following graduated series of forms connecting the subapterous. 
female with the typical worker. One specimen (fig. 2>a and h), meas- 
uring 6.5 mm. has the ocelH well-developed, the thorax rather small 
but with distinct mespnotum, scutellum, metanotum, paraptera and 
FIG. 2 
Subapterous, mesonotal female of Monomorium subapterum sp. nov., lateral view. 
tegulae, with stumps of wings and on the right side one nearly entire 
posterior wing. The latter is evidently vestigial, though its tip is lack- 
ing. The remaining vestigial wings have evidently been lost by dealation. 
This specimen is therefore a partially dealated female in a more ad- 
vanced stage of subaptery than the female of M. subapterum. A second 
specimen (fig. 3c) is slightly smaller and has a similar thoracic structure, 
except that the tegulae and paraptera are lacking and the thorax has 
never borne wings. A third and fourth specimen (fig. M) measure 
4.5-5 mm. and have small ocelli and the thorax is still more reduced 
and worker-like, but the mesonotum, though small and flat, is distinct 
and there is a visible promesonotal suture and a metanotal sclerite. 
The two remaining specimens, 3.5-4 mm. long (fig. 3e), are normal 
