144 BRITISH PAL.^OZOIC PIIYLLOCARIDA. 



PI. XVIII, figs. 5 a, h. Mus. Geol. Surv. Scotl., F ff and 23, No. 13. 



Size. — Length of valve 32 ram , including terminal spines ; breadth of valve 

 15 mm. 



Characters. — A single left valve, rather smaller than that in fig. 4, and with 

 a rather sharper mesolateral ridge, and the riin of the ventral margin depressed. 

 Otherwise the features are the same as in fig. 4. 



This specimen was described and figured in the ' Geol. Mag.,' 1874, p. 108, 

 pi. v, fig. 3. 



From black non-calcareous shale in the Ceraent-stone Quarry ; Lower Lime- 

 stone group, Glebe, East Kilbi-ide, Lanarkshire. Mr. Paton's Collection. 



Pi. XVIII, fig. 6 ; and PI. XX, figs. 1 a, h (magnified). Brit. Mus. No. 59541, 

 No. 9. 



Size. — Length of valve 35 mm., including the spines ; breadth of valve 14 mm. ; 

 breadth of the two valves 28 mm. 



Characters. — A pair of valves, united along their dorsal edges. The features 

 of each valve are as described for figs. 4 and 5. A short piece of the dorsal ridge 

 is preserved (magnified in PI. XX, fig. 1 a) ; and there is sufficiently clear indica- 

 tion of it and of its narrow lateral flanges throughout its extent on the hinder 

 two-thirds of the dorsal region. Posteriorly the dorsal junction ends in a nearly 

 square central notch, without any special prolongation. 



In " Coal shales," black, slightly calcareous, East Kilbride. Paton Coll. 



PI. XIX, figs. Q> a, h; and PL XX, figs. 3 a—g (magnified). Brit. Mus. 

 No. 59541, No. 10. 



Size. — Length of carapace, probably, 40 mm., when perfect; breadth of the 

 two valves 25 mm. 



Characters.- — Two valves of a carapace in apposition by dorsal attachment. 

 Though fractured by crush on the margins and posteriorly, it retains a consider- 

 able convexity (see PI. XX, fig. 3 b). The carapace has the same features and 

 characteristics as PI. XX, fig. 1, but it looks rather blunt in front, owing to 

 fracture and extension by pressure there. 



The two mesolateral ridges are very distinct, and the dorsal ridge is high 

 and well preserved (see PL XX, figs. 3 a, b, d,f, cj). It ends by fracture where 

 the test is broken away behind ; fig. 3 d shows its cross-section (magnified) and 

 its almost tubular cavity. 



The nuchal and gastric ridges are also well shown ; the latter seem to end 

 behind in ocular pits ; and the former have other and irregular elevations in tlieir 

 vicinity, near the front end of the dorsal ridge. 



From " Coal shales," black, slightly calcareous, East Kilbride. Paton Coll. 



