51 
Oh the whole all the bottoms referred to are of remarkably 
uniform nature. Sandy material, mixed more or less with clayey 
mud and clinkers. The last must have come from passing steamers, 
and a good deal of the darker portion of the fine muddy material 
may he also artificially brought in the same way. A few Hints (most 
of them quite minute) from the chalk occurred in almost every 
bottom, and probably these come from ballast, and may not properly 
belong to the localities in which they were dredged. The boulder 
clay of the coast (and no doubt also beneath the sea) may have 
furnished the greater portion of the clayey portion of the bottoms 
—more, I think, than the older carboniferous shales ; hut this 
must remain a matter for surmise only, and can scarcely be 
asserted with confidence. 
SHELLS FllOM STATION M. 
Puncturella noachina, L. — One, dead. 
Emarginula fissura. L. — A fragment. 
Trochus sp., juvenile, perhaps T. ziziphinus, L. — Broken. 
Triochotropis borealis (Brod. and Sow.) — A fragment, 
ltissoa striata, J. Adams. — Several, dead. 
Scalaria sp , probably Trevelyana (Leach). — Juvenile, broken. 
Odostomia unidentata (Mont. ) — Two, dead. 
0. interstincta i Mont.) — One, dead. 
Eulima bilineata, Alder. — One. 
Pleurotoma Trevelyana (Turton). — One. 
Defrancia linearis (Mont.) — A few, broken. 
Natica sp., probably catena (Da Costa). — Fragments. 
Buccinum undatum, L. — Juvenile. 
Venus ovata, Penn. — Several valves, juvenile. 
Astarte sulcata (Da Costa). — Several valves. 
A. compressa (Mont.) — A few valves, juvenile. 
Modiola modiolus, L. — Fragments of large specimen. 
Cardium edulo, L. — A fragment. 
Saxicava rugosa, L , v. artica, L. — One valve. 
Anomia epliippium, L. — A few valves. 
Nucula nucleus, L. — One valve. 
Crenella decussata (Mont.) — One valve. 
Axinus tlexuosus (Mont.) — A fragment. 
Mactra solida, L., v. elliptica, Brawn. — One valve, juvenile. 
