TRlASSlC INSECTS OF QUEENSLAND. 
39 
The Mt. Crosby insect horizon occurs nearly at the base of the 
Ipswich series (Text-figure 2). The age of this series has been deter- 
mined on palaeobotanical grounds as Upper Triassic (Rhaetic or 
Keuper ?). A rapid survey of the whole insect fauna from Mt. Crosby 
has given a strong general impression that its horizon is lower than 
that of the insect horizon at Denmark Hill. This is in keeping with 
the field evidence which places the Denmark Hill horizon as nearly at 
the top of the Ipswich Series. This higher insect horizon has been 
known for many years, and has been the subject of detailed geological 
and faunistic studies by Tillyard and Dunstan, but the more recently 
discovered Mt. Crosby horizon has yet to be adequately studied. This 
paper is only a preliminary account of one of the many interesting forms 
which the fauna contains. 
Con g lomera tc 
ABERDARE 
IPStncH (DEMMAB.K Hill) INSECT BED 
Bluff £>« Dirty 
Four- Foot 
0ERGIN5 
Strjeed Bacon 
Rob Roy 
Brae side. 
Garden 
Tantivy 
Cuffe's Upper or Fiery 
Clip ees LOWER OR 
Waters town 
Tivol / 
Bishop 
Ben ley 
Coal at Ipswich 
WA TER WORKS 
MT CROSBY /NSECT Bed. 
Text Fig. 2. 
Stratigraphical Section of Ipswich Coal Measures to show the positions of 
the two known insect horizons. (Modified from Cameron.) 
Family EOSETIDAE nov. 
Genus Eoses. 
Eoses triassicci gen. et sp. nov. (Plate Y). 
Forewing broad, costal margin straight in basal half, then evenly 
curved to a rounded point at R 4 ; hind margin rather evenly rounded. 
Costa with hm vein present, Sc 4 and Sc 2 present. Traces of a possible 
oblique cross-vein between Sc and R 4 . R x from R s in basal third of wing. 
Second radial fork at one-half; R 2 and R 3 long-forked; R 4 from R 5 
