H. H. Howorth—Traces of a Great Post-Glacial Flood. 15 
striatula, V. ovata, Scrobicularia piperata, Ostrea edulis, Anomia 
patelliformis, A. aculeata, Littorina littorea, L. rudis, L. littoralis, 
Trochus cinerarius, Natica nitida, N. Montagu, Lacuna pallidula, 
L. vincta, Turritella communis, Cerithium reticulatum, C. adversum, 
Purpura lapillus, Nassa reticulata, N. pygmea, Aporrhais pes-pelicani, 
Buccinum undatum, Fusus despectus, F. Turton, Trophon clathratus, 
var. minor, Mangelia linearis, Patella vulgata, Acmea virginea, Lepeta 
ceca, Dentalium entale, Balanus porcatus, B. crenatus, B. Hameri 
(Exposé des formations Quaternaires de la Suede, by A. Erdmann, 
pp. 92 and 98). The collocation of these forms is itself curious. 
The greater part of them still live on the coasts of Sweden, others 
now live further north, but the specimens from the beds are larger 
and finer than those now living in the same neighbourhood, proving 
that the conditions of life were then more favourable. Having 
examined the shells, we shall do well to turn to a notice, furnished 
by the author just quoted, of the remains of land plants found in the 
upper parts of this black clay, where exposed in a typical section at 
Enképing. Here he says is a quantity of vegetable debris of very 
different kinds, as, for example, stalks of Hquisetum limosum mixed 
with fragments of Conifers and of leaves of the Oak, Willow and the 
Aspen, leaves and cones of the Pine, twigs, branches and bark of the 
Fir, the Aspen, etc. With them are found the epidermous coverings 
of the Mytilus edulis, of which all traces of the shells have disappeared. 
These debris assuredly point a very important lesson. Oaks would 
not be growing, nor Pine trees bearing cones, in contiguity with a 
Glacial sea. 
If we come nearer home, we have a remarkable example in the 
marine drift at Kelsea Hill, at the mouth of the Humber, described 
by Mr. Prestwich in the 17th volume of the Geological Journal. 
From these beds Mr. Prestwich collected 40 species of shells. It is 
not necessary to enumerate them here, but I may add the conclusion ar- 
rived at by Mr. G. Jeffreys. He says, “ Although nearly all of the 
species comprised in the foregoing list still exist in the German Ocean, 
there are some which are only known as living in more northern seas.” 
Mr. Prestwich himself says, “The number of shells now obtained 
from these beds show, however, a more northern character than was 
at first apparent, and tend therefore, taken in conjunction with the 
occasional capping of thin seams of clay like a Boulder-clay, and 
the fact of a general development of gravels to the westward, to 
incline me to believe that these beds are to be referred to the upper 
part of the Boulder-clay. The shells are all of recent species, and 
30 out of the 40 are still found on the Yorkshire coast. Neverthe- 
less the presence of such species as the Natica clausa, N. Greenlandica, 
Trophon Gunnert, T. scalariforme, Mangelia pyramidalis and Littorina 
squalida, which have a wide northern and Arctic range, indicates 
colder conditions than those now prevailing on these shores, and 
more in accordance with what we know of the fauna of this portion 
of the Post-Pliocene series (op. cit. pp. 455, 456). What is very 
curious, however, is to find this same northern fauna associated not with 
individual sporadic shells, but with thousands of examples of the fresh- 
