CARBONIFEROUS BRACHIOPODA. 
265 
minute shells (wholly Brachiopocla) constitute, in the finest state of preservation, the chief 
feature of the deposit, and hundreds of specimens may be collected from one teaspoonful 
of the washed material. The only other bed in which we have found these shells at all 
plentiful is Brockley, but they are not nearly so abundant as in the Ayrshire deposit." 
I consider it desirable to append the details comdaunicated to me by Messrs. 
Neilson and Craig on the nature of the deposit in which this vast assemblage of minute 
Brachiopoda have been found, as I am not acquainted with any similar deposits either 
in England or Ireland. I am also much indebted to Mr. J. Smith, of Stobs, Kilwinning, 
for the inspection of a very large series of those minute or young Brachiopoda from 
Cunningham, Baidland, Billhead near Germiston, Garple Water, Muirkirk, Stack- 
lawhill, Stewarton, Limekilns, East Kilbride, Roughwood and Gateside, Beith, Brockley, 
Lesmahagow, Hallerhirst, Brankamhall, Hindogocglen, Dairy, Hill of Westerhouse, Car- 
luke, Auchenskeh, Dairy, Howrat ; to which localities Mr. J. Young has added William- 
wood, Cathcart, near Glasgow. 
Gems LiNGULA, Brugniere. 
1. LiNGULA ScoTicA, Bav. Caxb. Mon., p. 207, PI. XLVIII, figs. 27, 28; and Sup., 
PI. XXX, figs. 5 to 8. 
Since desoibing this fine species, Mr. R. Howse has found some twenty-four 
specimens of all sizes and ages, up to 20 lines in length by 17 in breadth, enclosed in 
nodules from the ironstone shales of Redesdale, Northumberland. Some of the 
specimens show a broken and repaired state of the front margin. The nodules which 
enclose the Lingulse assume so much the pear shape of the fossil that one is certain of 
finding in them a specimen of the shell before splitting the nodule for that purpose. 
Sf. oDaZt's, and Sf. lineata are in moderate plenty ; Streptorhynchus crenistria and its varieties being rather 
abundant. This refers to the general aspect. Nests occur where an otherwise rare shell may be very 
abundant. These nests are common to the limestone, and are always rich fossiliferous centres. The 
character of the limestone being slightly different where these occur, I am of opinion that their greater 
abundance is owing to some chemical action that has been the cause of better preservation, rather than 1 
to more prolific centres of life in the ancient sea. Whatever the cause may be these nests exist and account 
for the fossils being more prolific at some places than at others. It appears to me that this upper series 
of beds may have been deposited in a not over-deep sea, where the waves had action on the bottom. The 
lenticular nature of the beds is favorable to this view. Trearne, Dockra, and the quarries opened in the 
centre of the basin, have more of this character than Howrat and Waterland, although the two latter 
abut on the Trap Hills that rise from under the limestone. These are more evenly laid down, and 
have more the appearance of a deep-sea deposit, especially Howrat, where more Lamellibranchs are 
mixed up with the remains of Brachiopods than at Beith, and the limestone is not so pure, a larger 
part of the deposit being calcareous shale, and the part fit for making lime is reduced to 22 feet." 
