Palceozoic Bivalved Entomostraca. 363 



short sulci, and the small but prominent midlobe, reaching to 

 the dorsal edge, strongly distinguishing these species, we pro- 

 pose to separate them from their Beyrichian allies, under the 

 generic title of Klcedenia (see abovCj p. 347). 



EXPLANATION OF PLATE Xn. 



[All the figiu-es are magnified 15 diameters, except figs, 8 h and 13 6.] 



Fig. 1. Beyricliia Uihcrctilata (lOoden), var. gibbosa, Renter. With the 



hvpertrophied lobe, a, right valve ; b, dorsal view of carapace. 



Smith Coll. no. Og, 4. Dudley Castle. 

 Fig. 2. Bei/richia K/a;deni, M'Coy, var. granidata, Jones. With the big 



lobe. Smith Coll. no. 9j. Dudley Castle. 

 Fig. 3. Bejjrichia Kloedeni , M'Coy, subvar. subspissn, Jones, a, right valve ; 



b, dorsal view of carapace. Vine Coll. XLiv^. Bed 46. 

 Fig. 4. Beyrichia Kla'deni, M'Coy, var. intermedia, Jones. Right valve. 



Smith Coll. no. .55^. Woolhope. 

 Fig. 5. Beyricliia admixta, sp. uov. Right valve. Smith Coll. no. 55.^ 



Woolhope. 

 Fig. 6. Beyricliia Kia>deni, M'Coy, var. suhtarosa, Jones. Left valve, with 



one sulcus on the gigot. Vine Coll. xLvi. Tickwond Beds. 

 Fig. 7. The same. With two sulci on the gigot. Smith Coll. no. 34. 



Woolhope. 

 Fig. 8. Beyricliia Kloedeni, M'Coy, var. tubercidata, Salter, a, left valve ; 



b, portion magnified about 25 diam. Smith Coll. no. 18. Wool- 

 hope. 

 Fig. 9. The same, smaller form, subvar. c/rmsa. «, right valve ; &, dorsal 



view of carapace. Vine Coll. xlyii. Shales over Wenlock 



Limestone. 

 Fig. 10. Beyricliia Klosde/ii, var. scotica, nov. Hollow cast of a left 



valve, Mrs. Gray's Coll. Near Girvan. 

 Fig. 11. Beyricliia Maccoyiana, Jones, a, left valve; b, dorsal view of, 



carapace ; c, ventral aspect of carapace. Vine CoU. xLin,. 



Bed 25. 

 Fig. 12. Beyricliia Maccoyiana, Jones. Right valve. Young or variety. 



Smith Coll. no. 22g. Lincoln Hill, Ironbridge. 

 Fig. 13. Beyricliia Maccoyiana, Jones. «, right valve, with "big lobe;" 



b, portion of the hvpertrophied lobe, magnified about 50 diam. 



Smith Coll. no. 25. Railway-cutting, Ironbridge. 

 Fig. 14. BoUia bicolliiia, gen. et sp. nov. a, left valve ; b, dorsal view of 



carapace ; c, ventral view. Vine Coll. xlviiIj. Bed 22, 

 Fig. 15. Tlie same. Right valve. Vine Coll. xlviii^. Bed 22. 

 Fig. 16. The same, young. Left valve. Smith Coll, no. 55^. Wool- 

 hope. 

 Fig. 17. BoUia uniflexa, gen. et sp. nov. a, right valve ; b, dorsal view 



of the carapace. Vine Coll. xxxviii^. Bed 25, 

 Fig. IS. Beyricliia lacunata, ST^. uov. Left J q^vi, n ii kk 



Fig. 19. The same. Right valve. ( ..."^"^^^^^P®- tj j o- 



T7- on rr, -D^^.i,+ „i ^ I Vine Coll. XLV. Bed 2y. 



Fig. 20. The same. Right valve. ) 



Fig. 21. Klcedenia intermedia, Jones & IJoll, var. marginata, nov. o, 

 left valve ; 6, dorsal edge. Vine Coll. Liv,^. Bed 37. 



Fig. 22. Beyricliia concinna, nov. a, right valve ; b, dorsal view of cara- 

 pace. Smith Coll. no. 19. Dormingtou, near Stoke-Edith. 



