THE 8HELL-L1MESTONE OF DURHAM. 129 



some Glasgow specimens of great interest, in the Hiinterian 

 Museum, have also been examined by him; and a large collec- 

 tion of British and foreign Carboniferous specimens are in his 

 possession, through the kindness of friends: still he waits for an 

 opportunity (if possible) to study the original specimens from 

 Hof, brieliy described by Count Mimster. (Jahrbuch, ]830, 

 p. 65.) 



Of Permian specimens, he has obtained, through Dr. Richter's 

 courtesy, a series of those from near Saalfeld ; and some from 

 Gera, by the gift of Dr. Lieber of that j^lace ; besides other speci- 

 mens from Germany ; several from Byers' Quarry, near Sun- 

 derland ; and the whole of my collection from Tunstall Hill. 

 Still he hopes to see the Wetterau specimens described by Pro- 

 fessor Reuss; so as to determine the exact relations of several 

 specific forms. Nor is he without hope of seeing the Uralian 

 specimens collected by Schrenk, and described by Count Keyser- 

 ling. 



Commencing, then, with the Beyricliia-\^k.Q species, and adopt- 

 ing the new generic name proposed by Mr. Jones, I now repro- 

 duce the description of it given in the " Annals of Natural 

 History," 3rd series, vol. ii., with some modifications which Mr. 

 Jones has kindly suggested. 



KIRKBYA, Jones. 



K. Permiana, Jones. PI. X a, figs. 1-9 ; and plate X, figs. 5-13. 

 Dithyrocaris Permiana^ Jones. " Mon. Perm. Foss.," 



p. QQ,, tab. 18, fig. 1. 

 Ceratiocaris ? Permiana^ Jones. " Morris's Cat. 



Brit. Foss.," 2nd edition, 1854, p. 103. 

 Lejierditia ? Permiana, Kirkby, 1858, "Ann. Nat. 

 Hist.," ord series, vol. ii., p. 434. 

 Length, l-20th of an inch ; height, l-45th of an inch. 

 Carapace oblong-ovate, ark-shaped, equivalve, very con- 

 vex ; valves thick. Dorsal margin straight, bounded 

 laterally by flattish, slightly-inclined areas, formed by 

 the depression of the upper region of the valves. Ven- 

 tral margin straight centrally, or very slightly sinuate. 



VOL. IV. PT. IT. R 



