ANIMALS. 61 
calcareous Grit, and imbedded in the crystalline Limestone. They also occur, but much 
more sparingly, in the Limestone of Humbleton, and other localities. Species Nos. 
1 and 3 occur exclusively in the latter rock; No. 2 occurs in both rocks; and the 
others, except No. 4, have as yet been found in the Limestone from Byers’ Quarry only. 
No. 1. CytTHEerRE MorrisiAna, nobis. Tab. XVIII, fig. 2 a, 4, ¢. 
INCH. 
Length, = 
Height, 5 
Thickness, ;) 
Carapace wregular oblong, convex, smooth. Dorsal and ventral borders nearly 
straight, slightly curved. zxtremities subacute, suddenly depressed; the anterior 
slightly narrower than the posterior. 
Dorsal aspect elongate oval, compressed at the ends ; anterior sub-ovate. 
Unique. Locality, Humbleton. 
This well-marked species is named after Mr. J. Morris, to whose scientific 
researches paleontologists are so greatly indebted. 
No. 2. CyTHERE (BarrprA) curtTA, J/‘Coy. Tab. XVII, figs. 21, 22; and Tab. XVIII, 
fig. 3.a, 6, ©. 
Bairpra curtus, M‘Coy, 1844. Syn. Char., &c., p. 165, pl. xxiii, fig. 6. 
1 
Length, +5 as 
Height, 35 30 
Thickness, 1, sto 
Carapace sub-triangular, convex, smooth. Dorsal order projecting ; ventral sinuous. 
Anterior extremity rounded on its ventral half, and forming an angle with the sloping 
dorsal border ; posterior acute. 
Dorsal aspect narrow acute oval ; anterior compressed ovate. 
Several specimens exhibit, more or less distinctly, the interior of the valves, which 
closely resemble those of B. subdeltoidea, Miinster,' of the Chalk and Tertiary for- 
mations. ‘The cast (figs. 21, 22), in particular, is similar to the cretaceous species, and 
not very dissimilar to B. afinis, Morris,” but the generality of the Permian specimens 
are narrower, more compressed, and less triangular than the species referred to. 
Found by Mr. Griffith in the Carboniferous rocks of Ireland. 
Not uncommon at Byers’ Quarry and Humbleton. 
1 See Jones, Mon. Entom. Cret. Form., p. 23, tab. v. fig. 15. 
* Phys. Descript. New S. Wales, &c., p. 291, pl. xviii, fig. 10. 
