273 
Rev. T. G. Bonney — Formation of Cirques. 
Poravibonites, Köninck ina, and several otkers, which m ade ttieir ap- 
pearance verv snddenly and witliout any warning ; after a wliile they 
disappeared in a similar abrupt manner, having enjoyed a compara- 
tively short existence. They are all possessed of such iuarked and 
distinctive internal characters that we cannot trace between them 
and associated or synchronous genera any evidence of their being 
either modifications of one or the other, or of being the result of 
descent with modification. Therefore, although far from denying 
the possibilitv or probability of the correctness of the Darvvinian 
theory, I could not conscientiously affirin that the Brachiopoda, as 
far as I am at present acquainted with them, would be of muck 
Service in proving it. The subject is worthy of the continued and 
serious attention of every well-informed man of Science. The sublime 
Creator of the Universe has bestowed on kim a thinking rnind : there- 
fore all that can be discovered is legitimate. Science has this ad- 
vautage, that it is continually on the advance. and is ever ready to 
correct its errors when fresh light or new discoveries make such 
neeessary. 
The importance of the study of the Brachiopoda must be obvious 
to all. They are among the first well-known indications of life in 
this world ; and they have continued to be very extensively repre- 
sented up to the present time. They are also very ckaracteristic 
fossils, by which rocks at great distances, whether in New Zealand 
or Spitzbergen, in the Himalayas or the Audes, can be identified 
without its being even neeessary for the palason tologist to visit the 
district from whence the fossils are derived. The} 7 are, as Mantell 
would have termed them, sure medals of creation, the date of their 
appearance firmly stamped upon them, and their distinctive characters 
so legibly impressed as to defy misinterpretation. 
IV. — On Me. Hf.lland’s Theory of the Formation of Cirques. 
Bv the Rev. T. G. Bonney, M.A., F.G.S. ; 
Fellow, and late Tutor, of St. Jokn’s College, Cambridge. 
I N the Quarterly Journal of the Geological Society (vol. xxxiii. 
p. 142) is an important paper by Mr. Heliand, on Fjords, Lakes, 
and Cirques in Norway and Greenland. In this he notices a theory 
of mine on the formation of cirques which was published in the same 
journal (vol. xxvii.p. 312). As I mentioned in a note attached to his 
paper, he somewhat misunderstands me, supposing apparently that 
I describe only cirques of a small size, — the fact being, that, so far 
as I know, the Alpine cirques are quite commensurate with those of 
Norway. This, however, is of slight importance. My present 
purpose is to give reasons why, after further observations in the 
Alps and Pyrenees, and even in the British Isles, I still prefer the 
explanation then advanced, that the cirques are mainly produced 
by the combiued erosive action of streamlets, to the one given by 
Mr. Heiland, that a cirque is a result of glacial action. 
I must first remark that in the Alps the persistencv in direction. 
which he observes in the Norway and Greenland cirques, is not 
DECADE II. — VOL. IV. — NO. VI. 18 
