280 JOURNAL OF SCIENCE, 
they are still found in the first pump although the well has been filled 
up. Of Cruregens fontanus more than 40 more specimens have been 
obtained, all with only six pairs of legs. It was shown that in all 
probability these subterranean crustacea were derived from a 
marine and not from a fresh-water fauna. The rest of the paper 
was taken up with the description of another Isopod from the same 
well—Phyreatoicus typicus, nov. gen. et sp. Body elongated, some- 
what laterally compressed, abdomen long, of six distinct segments. 
In some points it resembles the Jdotetdw, but in others approaches 
the Anthuride and the Tanaide. 
(2.) Description of new species, and notes on New Zealand 
Desmidieze, Mr. W. M. Maskell.* 
(3.) Further notes on the Rock Shelter in the Weka Pass, by 
Professor von Haast, Ph.D., F.R.S. 
The main object of this paper was to prove that the partial 
destruction of the rock-paintings was due to the formation of lime- 
stone flakes, caused by mechanical weathering. A number of 
specimens were exhibited, both in illustration of chemical and 
mechanical weathering. To the former the darker layer near the 
surface is attributed. Professor Haast also gave a resumé of Mr 
George Gray’s chemical analysis of both the rock itself and the 
chemically weathered surface layer, to show the correctness of his 
views. He also maintained that Professor Hutton’s stalagmite 
crust was simply the outermost portion ofthe chemically weathered 
surface and an integral portion of it, and that the same in many 
instances did not exist. Mr George Gray’s chemical analysis with 
notes in confirmation, is added to this paper. 
Professor Hutton pointed out that the stalagmite formed a very 
thin layer, about 1-50th of an inch in thickness over the surface, 
and that it had the peculiar wrinkled appearance so characteristic 
of stalagmite; this layer, as the specimen he exhibited showed, 
was quite translucent, and must therefore be crystalline; conse- 
quently Professor Haast was wrong in saying that there was no 
crystalline structure on the outside. Underneath this crystalline 
layer was the dark layer alluded to by Professor Haast. Mr Gray’s 
analyses, although interesting, did not bear on the point in ques- 
tion, because he had taken as the outside a layer of more than a 
quarter of an inch in thickness, which therefore included a larger 
portion of rock. Professor Hutton then explained that when lime- 
stone weathered from frost the surface crumbled, as it was not 
sufficiently coherent to hold together in large thin pieces, but if the 
surface was coated with stalagmite this held the pieces together, 
and the surface then scaled off in flakes. He would ask Professor 
von Haast to explain how, if the changes were only in the rock 
itself, the paint, in one place at least, came to be covered by this 
outer layer? and also, if the surface of the rock never became 
wet, how the changes described by Mr Gray had been produced ? 
Professor Bickerton said that the outer portion ot the specimen 
analysed by Mr Gray was much harder than the inner portion. 
Mr Inglis pointed out that the surface of the ground above the 
cave was flat, and that there was a large “‘ swallow-hole ” in it. 
Professor Haslem said that when he visited the caves the sur- 
* The abstract of this paper unfortunately arrived too late for publication ; it will 
appear in next issue. 
