139 
G. W.. Lee — Trepostomata,. 
not only of Indian materials, but also of the common “ Stenopora ” columnaris (Scbloth.), 
of the Permian deposits of Western Europe. The current interpretation of Lonsdale’s 
genus Stenopora rests on the earlier definitions of Nicholson and Etheridge 1 , insufficient 
attention having been paid to an exhaustive memoir by Mr. Etheridge, published 
in 1891 2 , in which a new diagnosis is given, based on the examination of numerous 
Australian topotypes. 
The Upper Carboniferous rocks of Russia are rich in Trepostomata. Several 
descriptions of new forms, together with a revision of the old diagnoses of Lonsdale, 
Eichwald and Trautschold, are to be found in the monographs of Stuckenberg 3 and 
Romanowski. 4 
Although the Trepostomata can now be said to be well known as regards 
their morphology, there is still a branch of their study that awaits detailed research, 
namely, their ontogenetic development. Such work was attempted by Lindstrom, 5 and 
many valuable remarks have been made by Nicholson and by Ulrich, but an exhaustive 
study similar to that of Mr. Cumings on the development of the Fenestellids has yet 
to appear. 6 
The principal object of the present contribution is to provide the working palaeon¬ 
tologist with the means of giving an intelligible record of the occurrence of forms 
which, on account of their general distribution, are likely to prove of value in zoning 
the Carboniferous rocks of this country. 
Since the identification of the various species of Trepostomata rests on the 
interpretation of outstanding and structurally important features, it has been found 
possible to classify them in a satisfactory way; and in this respect the methods 
used are-somewhat comparable with those applied to the Corals, Once the principles of 
classification have been mastered, most forms can readily be identified and comparisons 
between the better characterized species can be effected by means of fairly exact terms. 
Throughout the following pages, the register-numbers of individual specimens are 
given in square brackets. The specimens are in the Survey collections, except when 
otherwise stated. 
2 7. 
4 35. 5 18. 
26, 27, 28, 29. 
3 38, 39. 
0 3, 4. 
