DAVIDSON — SCOTTISH CAUBONIPEROUS BRACHIOPODA. 
15 
the hingo side, but arc wide apart in front. Tlio liini^c-plato is divided inio 
two portions, to wliicii the principal stems arc attaclied,' and in tlic notch under 
tile extreinity of the uinboual bealv there exists a calearcnns projection, to 
whicli tlic term "cardinal" process lias been ai)plied, and to wiiicli was attached 
one of the extremities of tlie divaricator muscle. A little lower down, on the 
bottom of the valve, arc seen four large elongated impressions, produced by 
the adductor, and which have been recently designated as the anterior and r)os- 
tcrior ocelusor muscles by Mr. Hancock. 
Lign, 4.— Interior of Athi/ris amhigim, showiiig the spiral appendages. 
Lign. 5.— Interior of the dorsal valve of Spirifera striata. 
pe«i;s:tJS::5 '° ^^"'^ '^^p^^'- ^^^^^^^ ^ 
The species of ciirboniferous Spirifcm that appear to have been hitherto dis- 
covcre^ in Scotland, arc not so numerous as those of England or of iXd ■ 
ana atter a careful examination of many specimens, I could determine wit) 
certamty but the nine foUowing -.-Sp. duplLosta, Sp. biszacata,s"o^s, 
