26 Professor Percy Kendall—Glacier Lake Channels. 
surface of the valves is ornamented with about thirty ribs, which 
are rather more angular and squamose than in typical nzgricans ; 
a mesial septum is also visible through the shell of the dorsal valve. 
Without spoiling the specimen it would be impossible to study the 
internal characters. 
The two other specimens, one broken, the other perfect, are quite 
distinct from that described. The valves are ornamented by about 
forty-six radiating coste, increasing by bifurcation. The cost are 
divided by moderately deep furrows and are surmounted by short 
tubular spines which are arranged concentrically, following the 
growth-lines. The dimensions of the perfect specimen are as follows: 
length 16°5mm., breadth 19 mm., depth 7°5mm. ‘The imperfect 
example represents a shell of approximately the same size, and is 
interesting as it exhibits the internal characters. The teeth of the 
ventral valve are supported by very distinct dental plates, which 
ditfer entirely from those of H. nigricans by being almost vertical 
and more like those of H. psettacea. The foramen is rather large and 
the pedicle collar somewhat weak, as are also the deltidial plates. 
The dorsal valve possesses a thin mesial septum extending to the 
apex, while the dental sockets and crural bases are more divergent 
than in H. nigricans and psittacea. No cardinal process is visible. 
I am unable to identify the above species with accuracy owing to 
the absence of specimens for comparison, but it seems to be related 
to Rhynchonella squamosa, Hutton = calata (M‘Coy MS.), Woods = 
pyxidata (Watson MS.), Davidson. 
Hemithyris imbricata, Buckman,’ from the Miocene-Oligocene beds 
of Cockburn Island, off Graham Land, Antarctica, is near to it in 
general appearance, but this species appears to possess no dental 
plates. 
Another species possessing some resemblance to the one under 
discussion is Rhynchonella (?) tubulifera, Tate,* from the Oligocene of 
Muddy Creek, Victoria. 
VIl.—Guactrr Lake CuHannets. 
By Percy Fry KENDALL. 
N 1902 I published a paper,? the outcome of several years’ 
observation, on certain phenomena associated with the glacial 
deposits of the Cleveland area, which I attributed to the former 
presence of a series of temporary lakes and lakelets upheld in the 
recesses of the hills by the margin of a great ice-sheet occupying 
the greater part of the North Sea. This interpretation met with 
so wide an acceptance, even by those geologists familiar with the 
district who had previously attributed the glacial deposits to a marine 
origin, that during the succeeding thirteen years I have steadfastly 
refrained from replying to criticism, hoping by this abstention to keep 
the issues unclouded by a controversy that might at any stage 
develop an acerbity not always lacking in earlier discussions. 
1“ Antarctic Fossil Brachiopoda, etc.’’: Wiss. Ergebn. Schwed. S.P. 
Exped., 1901-3, Bd. iii, No. 7, 1910. 
2 Trans. Roy. Soc. S. Australia, xxiii, p. 257, 1899. 
3 Q.J.G.S., vol. lviii, pp. 471-571. 
