MM. Jones and Kirkby — Carboniferous Ostracoda. 435 



mentioned, the external impressions of the valves show this feature 

 very beautifully. 



PL XI. Fig. 7 is an internal cast of a valve with the external im- 

 pression of the fringe. 



Fig. 8 is a very fine testiferous example, from Staneshiel Burn, 

 with a well-developed and ornate crest, and a curious palmate 

 spine (?) near the postero-dorsal angle. 



This species is always found in deposits of marine origin. At 

 Plashetts it is associated with marine fossils, besides other Ostracods 

 in abundance, such as Kirkbya costata, Beyrichia radiata, Leperditia 

 Okeni, Cytherella valida, etc. 



At Billow Ness it occurs along with Bellerophon decussatus, Mur- 

 chisonia striatula, Leda attenuata, Sanguinolites abdensis, etc., and 

 with Leperditia Okeni and other Ostracods. 



PL XII. Fig. 5 represents a fringed form from Cultra, County 

 Down, Ireland, which probably belongs to this species, though the 

 crushed state and general bad preservation of the specimens leave 

 the reference doubtful. 



Localities. — Calciferous-Sandstone series. Plashetts, Northum- 

 berland ; Tweeden Burn, and Staneshiel Burn, Koxburghshire ; 

 coast to the west of Billow Ness, Fifeshire 1 ; ? Cultra, County Down. 



Carboniferous-Limestone series. Murrayfield Pit, Linlithgow- 

 shire ; and Sunnybank Quarry, N. W. of Kirkcaldy, Fifeshire. 



2. Beyrichiopsis fortis, sp. nov. PL XII. Figs. 1-3. 

 (Var. glabra, Figs. 1,2; Var. granulata, Fig. 3.) 



Another fringed form, nearly related to fimbriata, occurs in the 

 Lower-Carboniferous Shale at Staneshiel Burn, Liddlesdale. It is 

 larger than the latter, and, were it not for the marginal fringe and 

 longitudinal ribs, would have a veiy Beyrichian style of valve. We 

 have been in some doubt whether to consider it a variety of fimbriata 

 or a distinct species, but adopt the latter view, and describe it as 

 follows : — 



Obliquely subovate, lobed, longitudinally ribbed, and with a 

 marginal fringe ; height less than half the length. Dorsal border 

 straight and three-fourths of the valve's length ; ventral border 

 boldly convex ; extremities rounded, but with well-marked dorsal 

 angles, the anterior extremity oblique and larger than the other. 

 The posterior half of the valve is swollen and forms a large rounded 

 lobe, in front of which, and separated by a deep and narrow sulcus, 

 is a small oval boss ; the ventral portion of the valve is tumid. A 

 thin, sinuous rib passes obliquely across the valve from near the 



1 The thin limestone or " cement -stone " at this locality is only about one foot 

 thick. It is a compact and very hard grey stone, showing scarcely a trace of fossils 

 as it occurs unaltered between tide-marks. A little higher up, where it runs into 

 the soil and a recent shell-bed (old beach), it becomes decomposed, especially about 

 the joints, and takes the character of a soft, yellow ochre, that is easily split up with 

 a pocket-knife or needle. The rock is then seen to be literally full of the remains 

 (casts or impressions) of Mollusca and the carapace-valves of Ostracods. The con- 

 trast of how much is to be seen in a piece of this rotten stone in comparison with 

 how little iu a piece of the unaltered stone is most surprising and very instructive. 



