THE ESSEX FIELD CLUB.
131
Mr. C. B. Sworder exhibited a small collection of Mollusca from the
neighbourhood of Epping.
Some photographs were then thrown upon the screen by Mr. Wire, consisting
principally of views taken by himself during the last year's field meetings, views
of the Higham Park from drawings by Mr. H. A. Cole, and some copies of old
prints of Essex localities, &c.
The President then called upon Mr. Walter Crouch, F.Z.S., to speak on the
main exhibits of the evening, consisting of a goodly number of specimens from
his collection, which he had selected in illustration of the characteristic species
of a few important groups of invertebrate life, and showing as far as possible the
Foreign, British and fossil forms. The shells of the Mollusca were arranged in
seven large cases, with larger specimens and fossils on the tables ; and to aid in
the demonstration, a series of diagrams, painted by himself, were hung on the
walls.
The five classes into which the Mollusca are now divided were then hastily
reviewed.
The varied forms of Cephalopoda, including the Pearly Nautilus with its fossil
allies the Ammonites—the Cuttle Fish, Squids—one of which, the common
Loligo, was shown in spirit—and fossil Belemnites, &c.—the Octopus, and the
Argonaut with the delicate fragile "shell" secreted by the female, which is but a
"cradle" for the protection of the young fry, were duly noted. The largest of
this group, of which a diagram was shown, is the Architeuthis, which has often
been known to measure sixty feet from end of the body to tip of the long
grasping arms.
The small glassy shells of the Pteropoda or "butterflies of the sea," were then
described—those "winged" forms floating always on or just below the surface of
the ocean. The northern species—some of which are shell-less—provide food for
the huge Greenland Whale. One of the larger species, a fine specimen over
21/4 inches in length (Cymbulia peronii from the Mediterranean Sea, a form which
has no shell), was exhibited, well preserved in spirit. Many of this class exhibit
phosphorescence at night.
Then the small division of Scaphopoda, mud and sand dwellers, of which the
little "elephant's tusk" shell, so commonly cast up on the British coast, is a
well-known example.
The extensive class of Gastropoda next claimed attention, from the small
land shells and slugs to the large and brightly-coloured tropical marine species;
and the growth of the shell from the "capsule," in which the eggs are laid, up to
the fully grown shell of nearly two feet in length, was shown by specimens of a
large Fusus proboscidiferus from Dampier's Archipelago.
Special notice was called to the wonderful variety, in shape, colour, and
beautiful patterns, which exists, especially in tropical shells. The spiny shells of
Murex, the brilliant colouring of Volutes, Coues, Mitras, &c., the enamel of
Cowries, Olives, and Poached-egg shells, the curious "keyhole" limpets, the
shells used for cameo cutting, the frail glassy shell of Catinaria, and such aberrent
forms as Chiton, &c.
A large Triton variegatus was shown, and the mode in which it had been used
as a trumpet by some dusky native of the Eastern Archipelago to strike terror
into the hearts of his enemies ; and also a drawing of the same shell with a finely
carved Maori mouthpiece, now in the Chelmsford Museum.
The last class, Pelecypoda, was then described, the shells of which consist of
two valves united by a ligament, and generally having a number of inter-locking