200 
ELEMENTS OF GEOLOGY. 
ing exclusively to the section Trivia^ is remarkable. The 
large volute, called Valuta Lamherti (Fig. 123, p. 196), may 
seem an exception; but it differs in form from the volutes 
of the torrid zone, and, like the living Valuta Magellanica^ 
must have been fitted for an extra-tropical climate. 
The occurrence of a species of Lingula at Sutton (see Fig. 
129) is worthy of remark, as these JBrachiapada seem now 
confined to more equatorial latitudes; and the same may be 
said still more decidedly of a species of Pyrula^ supposed by 
Mr. Wood to be identical with P, reticulata (Fig. 130), now 
living in the Indian Ocean. A genus also of echinoderms, 
called by Professor Forbes TemnecJiinus (Fig. 131), occurs 
Fig. 129. Fig. 130. 
hingula Dumortieri, Pyrula reticulata, Lam.; 
NystSuffolk aud Coralline Crag, Ram- 
Antwerp Crag. sholt. 
Fig. 131. 
TemnecMnus excavatus, Forbes; 
Temnopleurus excavatus, Wood; 
Cor. Crag, Ramsbolt. 
in the Red and Coralline Crag of Suffolk, and until lately 
was unknown in a living state, but it has been brought to 
light as an existing form by the deep-sea dredgings, both 
of the United States survey, off Florida, at a depth of from 
180 to 480 feet, and more recently (1869), in the British seas, 
during the explorations of the “ Porcupine.” 
Climate of the Crag Deposits. —One of the most interesting 
conclusions deduced from a careful comparison of the shells 
of the British Pliocene strata and the fauna of our present 
seas has been pointed out by Professor E. Forbes. It ap¬ 
pears that, during the Glacial period, a period intermediate, 
as we have seen, between that of the Crag and our own 
time, many shells, previously established in the temperate 
zone, retreated southward to avoid an uncongenial climate, 
and they have been found fossil in the Newer Pliocene strata 
of Sicily, Southern Italy, and the Grecian Archipelago, where 
tliey may have enjoyed, during the era of floating icebergs, 
a climate resembling that now prevailing in higher Europe¬ 
an latitudes.^ The Professor gave a list of fifty shells which 
inhabited the British seas while the Coralline and Red Crag 
were forming, and which, though now living in our seas, 
* E. Forbes, Mem. Geol. Survey Gt. Brit., vol. i., p. 386. 
