PLATE XXI. 
Fig. 1.—Carbonicola acuta. The original of Ure’s ‘‘ mussel” from East 
Kilbride. In the Collection of the Royal Society of Edinburgh. (Page 175.) 
Fig. 2.—Anthracomya subparellela. The original of Portlock’s Modiola 
subparellela. In the Collection of the Geological Survey, Jermyn Street. 
(Page 176.) 
Fig. 3.—Anthracomya subparallela. A specimen showing the hinge, in the 
Collection of the Belfast Museum. (Page 176.) 
Figs. 4, 5.—Anthracomya subparallela. From Carboniferous shale, Slieve 
Gullion, co. Derry. In the Collection of the Geological Survey, Dublin. (Page 
176.) 
Fig. 6.—Anthracomya subparellela. A cast showing the muscle-scars, from 
the Carboniferous of Ballycastle. In the Collection of the Belfast Museum. 
(Page 176.) 
Fig. 7.—Anthracomya Phillipsii. Not crushed. From the Gloucester Coal-field. 
My Collection. (Page 176.) 
Fig. 8.—Carbonicola nucularis. Large form from the “ Cockle-shell” band 
above the Rusty Pack seam, St. Helens. My Collection. (Page 174.) 
Figs. 9, 10, 10 a.—Anthracomya Wardi. Very large specimens from the Possil 
Lower Ironstone, Scotland. In the private Collection of Dr. John Young of the 
Hunterian Museum, Glasgow. (Page 175.) 
Figs. 11,11 a, 12.—Carbonicola robusta, from the Drumgray Coal, Shotts. To 
show the eroded umbones. My Collection. (Page 174.) 
Fig. 13.—Anthracomya dolobrata. A young specimen from the Lancashire 
Coal-measures. In the Collection of the Owens College Museum. (Page 176.) 
Fig. 14.—Anthracomya senew. Lancashire Coal-measures. My Collection. 
(Page 175.) 
Fig. 15.—Anthracomya dolobrata. Medium-sized specimen, somewhat shortened 
by crushing, from the Coal-measures of Lancashire. My Collection. (Page 176.) 
