DREDGING IN THE RIVER CROUCH. 91
representing the septal orifice, and in this variety there are longi-
tudinal ribs or striae.
The record so far, therefore, is not a very large one ; but nearly all
the great divisions of Invertebrate life are represented by one or more
species. These are but a few in comparison with the forms of life
in the sea, which appear to be quite inexhaustible; and the collec-
tions made by various scientific expeditions give us perhaps but an
idea of the abundance of it. All around our own coast (not to
mention the great oceans beyond), there are vast tracts which have
never yet been touched by trawl or dredge, reminding us of the lines
in Spenser's "Faerie Queen":
"Oh what an endless work have I in hand,
To count the seas' abundant progeny,
Whose fruitfull seede farre passeth those in land,
And also those which motive in th' azure sky."
The results of deep-sea trawling have also entirely disproved the
hypotheses of the older naturalists with regard to the limitation of life
at great depths, where the pressure and density of the water is
enormous. Dr. Wallich's report on "The North Atlantic Sea-bed"
in the "Bulldog," 1860, and the later expeditions of the Porcupine,
Challenger, and others, have proved the existence of marine life at
tremendous depths, extending to about three miles, some of which
are especially adapted to their environment; and that any limit is
not so much affected by the depth as by the temperature.
When once an attempt is made to illustrate our marine fauna in
an Essex local museum, there is little doubt but that such expedi-
tions as those recorded by Mr. Fitch and myself would for a long
time contribute many new records; and much more satisfactory
results would be obtained when once the more general species in
each order are sufficiently represented, which might then be passed
over for the rarer and less-studied genera and species. The plethora
of marine life is so great that, in the attempt to collect or preserve all
that is caught, many of the more interesting, and especially the
minuter, forms are lost opsor ilt. A commencement that would lead
to better results might be made by a competent committee under-
taking a week's systematic work in the spring, and again in the
autumn, who would contribute full reports, to which additions might
from time to time be made as opportunity offered. Some of our
members would probably undertake to work out the more difficult
groups, e.g., Zoophytes, Polyzoa, &c.
H 2