Marine Zoology. 391 



Among sixty- four dredging papers from the Clyde district and the 

 Hebrides, twenty-two exhibit numbers either of bivalves or univalves 

 above ten ; of these three come within the Laminarian division, and 

 one from depths very close to shore ; in two of these the number of 

 species of living univalves prevails ; in one, of the bivalves. From 

 the upper part of the Coralline zone, there are eleven papers, in six 

 of which the bivalves prevail, all from muddy or sandy bottoms, 

 sometimes mixed with stones, close to shore ; in two, univalves pre- 

 vail over bivalves, in gravelly and stony bottoms near shore ; and 

 in two, the numbers are nearly equal on stony and mixed bottoms 

 near to shore. From depths between 40 and 60 fathoms, there 

 are six prolific papers, all richer in bivalves than in univalves, and 

 all from sandy, gravelly, or muddy beds, varying from two to ten 

 miles from shore. A bottom of gravel and sand in 90 fathoms 

 close to shore, is richest in bivalves. 



Of thirty papers from the Zetlands, sixteen are rich in species ; 

 one only is from the Laminarian zone, on a sandy bottom, especi- 

 ally rich in living bivalves (thirty), and having many (fifteen) uni- 

 valves also. Of two from the upper part of the Coralline zone close 

 to shore, one, with a nullipore and stony bottom, is richest in uni- 

 valves ; the other, from a shelly bed, in bivalves. Of the thirteen 

 remaining papers from depths between 40 and 100 fathoms, eight 

 present considerable numbers of both univalves and bivalves, and in 

 five (all from depths below 60 fathoms) bivalves prevail. The 

 numbers of species of bivalves are high in the depths at a consider- 

 able (30 to 100 miles) distance from shore. The bivalves are also 

 predominant at these great depths on more or less muddy bottoms, 

 and at the further distances ; the univalves most numerous alive 

 where the bottom is more or less stony. 



{To he continued in our next Number?) 



On Fossil Ttain-marks of the Becent Triassic and Carboni- 

 ferous Periods. By Sir Charles Lyell, F.R.S., F.G.S. 



Mr John Cunningham, F.G.S. , in the year 1839, read a paper 

 before the Geological Society on Impressions and Casts of Props of 

 Rain discovered in the Quarries of Lower New Red Sandstone at 

 Storeton Hill, Cheshire.* After he had inferred their pluvial origin, 

 he pointed out the indentations on the spot to Dr Buckland, who 

 recognized the correctness of his interpretation.')' 



When, in 1841, I visited the quarries of new red sandstone at 



* Proceedings Geol. See., vol. iii., p. 99. 



t Mr Cunningham, the author of the notion about Rain-prints, will observe 

 from the above notice that Sir Charles Lyell now does him justice. — Ed. PhiL 

 Journ. 



2c2 



