244 THE ESSEX FIELD CLUB.
Hydractinia echinata (on various shells), Sertularia abietina, Hydrallmannia
falcata, and Thuiaria thuia.
The Echinodermata were represented by S. papposa, and Ophiothrix
(" brittle-star ").
WORMS. Good specimens of Sabella penicillus, in their leathery tubes, were
brought up, and in their new abode, in the bottles and aquaria, soon displayed the
delicate mottled plumes, as though they sought for admiration.
On an old oyster shell was a tube of Terebella conchilega, with its rough
exterior composed of broken fragments of shells and stones, but the annelid-
builder was no longer within.
On the Laminaria, a host of the tiny spiral calcareous tubes (which simulate
a true shell) occurred, the shelter of the delicate plumed Spirorbis nautiloides.
Many other species of Marine Worms of the genera Phyllodoce, Nereis,
Polynoe, Nephthys, &c., were taken, and it is hoped that they may be subsequently
worked out.
SPONGES. Some grand specimens of Grantia compressa and G. ciliata (of the
former two very large ones) were brought to the surface, which were pronounced
by Dr. Taylor and Mr. Crouch to be the largest they had ever seen. One of
these measured 7 inches in length, and 21/4 inches in breadth, and is prettily lobed.
Chalina oculata, and Halichondria panicea (" The Crumb of Bread Sponge ") were
abundant, as on the previous occasion ; and a number of the small but very
interesting Sycon ciliatus, with its tri-radiate calcareous spicules around the
osculae. The largest one taken is barely half-an-inch long.
Mollusca. A larger number were captured than on the previous trip,1 when
only sixteen species were recorded. These (with two exceptions—Saxicava and
Foils') were again taken, and Mr. Crouch has now been enabled to add twenty-
one to the list, making in all thirty-seven species. Of these, nine were in the
River Stour, and in the following list Mr. Crouch has detailed these and marked
those which had occurred in 1890.
A large specimen (dead) of the northern shell Fusus norvegicus was dredged
up ; but this cannot be taken as indigenous, as they have been brought here at
different times with oyster spat from the North Sea, the Dogger Bank, &c.
LIST OF MOLLUSCA OBSERVED IN THE ORWELL AND STOUR
ESTUARIES.
(Species marked * occurred also in 1890.)