154 Sedimentary Formations 
and acknowledged authorities in Palaeontology out. of the Colony, and I am 
proud to acknowledge that I have found many able and willing coadjutors 
who have in ninny instances given me gratuitously the heartiest and most dis¬ 
interested assistance. 
It is with the intention of acknowledging this aid that I have said so much 
respecting my two friends—Lonsdale, with whom I became acquainted more 
than half a century ago, and Salter, with whom my acquaintance was more recent. 
The following arc extracts from the letters of Mr. Salter in continuation of 
former quotation:— 
“Museum of Pract. Geology, 
“ Jenny u-street, London, 
“ May 9, 185fi. 
“ I should have answered your letter some time ago (I have had it a few 
weeks only in hand), but for the very reason that prevents my being able to 
work at the Australian fossils in the way I should like. I thought to have 
given you some additional information respecting them, hut it is, I find, im¬ 
possible at present, owing to the pressure of work falling on my department 
- a sad hiatus being made iu all my calculations, and a period put to mueli 
important work by the lamented death of Forbes, lie could scarcely over¬ 
take the work that necessarily tails on those who have to help every one with 
fresh studies in the fossil groups, and how am l to expect to do it V We are 
finishing off our own Silurian work for England, and besides are compelled to 
attend to the wants of all the other departments of British geology. Under 
these circumstances, it will be utterly impossible to make any fresh detailed 
examination ol the fossils you mention. The abstract sent to you by Sir 
[Roderick will have clearly answered one of your most important queries, 
since there can he no doubt of a true Upper Silurian formation among your 
fresh fossils ; the presence of Ca/t/mene, JEncrinurus , and a plaited Pent a- 
uterus quite settles that question. Iteceplantlites, too, is a good Silurian 
genus when combined with such fossils as the above. 
“1 have some time had iu contemplation to give a short paper oti some 
fossils of Yarralumla, collected long ago, which are undoubtodlj’ Silurian, but 
now your new fossils have arrived it will enable me to add a figure or two of 
t he principal species of these, when a temporary leisure may enable me to 
attack them. It will not be at present, but; it will be a pleasure to me when 
I have the time. Yours very sincerely, 
* J. AY. SALTER ” 
“ Mus. Pract. Geology, Jermyn-st., 
“ London, Nov., 28, 1858. 
“ Your letter, just come to band, convinces me that your Colony will no 
longer need any illustration from Home. 
“ The specimens which you kindly sent t o Cambridge, and which I have 
examined in thorough, are, I am glad to find, only duplicates. I have not 
attempted to define their species. To do so would’ be to work' them out, and 
I could, of course then send you an account of them easily. Mv avoca¬ 
tions do not permit me any leisure; and though the presence* of the 
genera I meiilioned do certainly indicate the Upper Silurian, yet the great 
abundance of corals, both millepore and cupcoruls, with Produelus and 
Atn/pa reticularis , is an association we never meet with hero below’ Devonian, 
still 1 cannot, give you any specific names, except the very few opposite (vide 
list, p. 151). The Recoplneulitcs is a beautiful thing that helps to illustrate the 
genus for which I have long ago had materials, and if you allow me to des¬ 
cribe that species along with another from Canada I shall be glad to do so. 
“Yours faithful]v, 
“J. AY. SALTER.” 
