Iflf. Jones and Kirkby — Carboniferous Ostracoda: 439 



compressed-ovate, pointed at the ends. Surface smooth ; length - 3 V 

 of an inch. Many specimens are relatively higher and shorter than 

 the one figured. Discovered by Mr. John Young, F.G.S. 



It is found in the Carboniferous-Limestone series at Charlestown, 

 Sunnybank Quarry, and near St. Monans, in Fifeshire ; at High 

 Blantyre, Lanarkshire ; and Whitebaulks, near Linlithgow. 



4. Beyrichia craterigera, G. S. Brady, MS. PI. XII. Figs, la, lb. 



Another species with a strong free-marginal overlap may be 

 described thus. Obliquely oblong ; equal in height, dorsal and ven- 

 tral borders, being nearly parallel ; extremities rounded, with a 

 forward swing ; a deep sulcus near the anterior third, and another 

 passing forward to the antero-dorsal angle. Valves convex, the 

 right overlapping the left very strongly ; lateral contour cuneiform ; 

 shell thick ; surface strongly reticulated. Length - 2 V to -2V inch. 



This fine species was discovered by Mr. David Robertson, F.G.S. , 

 of Glasgow, in the Carboniferous-Limestone series, at Calderside 

 Quarry, Lanarkshire ; it also occurs in Lower-Carboniferous rocks 

 at Woodend Quarry and Plashetts, Northumberland ; and at Arnside, 

 "Westmoreland. 



EXPLANATION OF PLATES. 



Plate XI. 



(All the Figures, except Figs. 7 and 8, magnified 25 diameters.) 



Fig. 1. Beyrichiopsis subdentata, J. and K. ; left valve; 2, right valve. Plashetts. 

 ,, 3. B.Jimbriata, J. and K. ; left valve ; fig. 4, left valve. Plashetts. 

 ,, 5. ,, right valve. Tweeden Burn. 



,, 6a. ■,, ventral edge of left valve; 6b. dorsal edge of right valve. 



Plashetts. 

 ,, 7. ,, cast of left valve, with impression of its fringe ; magnified 



40 diameters. Billow Ness, Fife. 

 ,, 8. ,, right valve ; magnified 30 diameters. Staneshiel Burn. 



,, 9a. ,, ventral edge of left valve ; 9b. dorsal edge of left valve ; 9c. 



hinder end view ; a and c showing the fringe. 

 ,, 10«. ,, carapace, showing left valve; 10£. dorsal view. Tweeden 



Burn. 

 ,,11. B. comuta, J. and E. ; right valve. Linlithgow Bridge. 



Plate XII. 



(All the Figures, except Fig. 3b. magnified 25 diameters.) 



Fig. la. Beyrichiopsis fortis, var. glabra, J. and E., left valve; lb. dorsal edge 

 of right valve ; lc. ventral edge. Staneshiel Burn. 

 ,, 2. ,, ,, „ left valve. Staneshiel Burn. 



,, 3a. ,, ,, var. gi anulata, J. and K. ; right valve ; 35. hind end 



view, magnified 30 diameters. Staneshiel Burn. 

 ,, 4. B. simplex, J. and K., right valve. "Warksburn. 

 ,, 5. B.Jimbriata (?), J. and K., left valve. Cultra, Ireland. 

 ,, 6a. Bey richiella cristata, J. and E., carapace showing left valve; 6b. dorsal 



view. Randerstone. 

 ,, 7a. Beyrichia cratigera, G. S. B., carapace showing left valve; lb. ventral 



view. Arnside. 

 ,, 8. B. fasligiata, J. and E., thick-shelled carapace showing cast of left valve. 



Sunday-night Cleugh. 

 „ 9 and 10. ,, right valves (thin-shelled). 



,, 11a. B. Bradyana, J. and E., carapace showing left valve; \\b. ventral view. 

 „ 12. B. arcuata (Bean), right valve. Stylton, Durham. 

 ,, 13. ,, ,, cast of right valve. Carluke. 



„ 14. ,, ,, left valve. Longton, Staffordshire. 



