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SUPPLEMENT TO THE ERFITSH 
preserved examples at Scremerston Quarry, near Berwick, in Northumberland, as well as 
in some localities in Eifesliire. A specimen doubtfully referred to this species has also 
been met with at Auchenmade Quarry, near Dairy in Ayrshire ; arid many others will no 
doubt be found elsewhere. In his excellent paper, of which we have endeg-voured to 
reproduce the substance, Mr. R. Etheridge recapitulates the habits and mode of life 
of the Producti, stating that " some writers contended that the various species lived 
a free and independent life ; others, on the contrary, conceived that they were attached 
by muscular fibres passing from the interior of the shell, and in fact acting the part of 
a byssus ; whilst others believed that their position during life was at least aided by 
the long tubes or spines Avhich usually ornament their surface." Their habits and the 
use of their spines Mr. R. Etheridge, jun., sums up under the two following headings. 
" A. Habits. 
" The Producti were regarded as — 
" 1. Free shells, by Fleming, Deshayes, de Verneuil (partly), and Chenu. 
" 2. Living with the ventral or convex valve downwards, by Sedgwick and Mur- 
chison, Keyserling, and d'Orbigny [and partly by Davidson]. 
" 3. Attached by tendons passing through tubes arranged along the hinge-line, 
under the general name of Leptcena, by von Buch (an opinion afterwards abandoned). 
" 4. Attached by means of a peduncle passing through a central triangular foramen, 
by Bouchard-Chantreaux. 
" 5. Attached by fibres passing between the free edges of the shell, by de Koninck, 
Geinitz, and Eichwald. 
" 6. Probably attached when young, but a few permanently attached, by S. P. 
Woodward. 
" 7. Attached by spines (in the case of the allied genus Strophalodd), by King and 
de Koninck {fide Davidson). 
" B. Spines. 
" The spines were considered — 
"1. To be for the passage of tendons of attachment, by von Buch. 
".2. To be for the introduction of water into the interior of the shell, by de 
Verneuil. 
" 3. To be for simply retaining the shell in position in fine sediment, by d'Orbigny. 
"4. To be without essential functions, by Bronn. 
"5. To be of unknown function, by Eichwald. 
" 6. Not to serve as means of attachment to the shell, by de Koninck and de 
Verneuil. 
" 7. Not to act as a conduit to the interior to the shell, by de Koninck and Bronn." 
