42 BRITISH PALEOZOIC PHYLLOCARIDA. 



imbricate lozenge-shaped, or sharp leaf-like lines, each angle inclosing a smaller 

 leaf-like lattice-work, as in Barrande's G. Scharyi : all are pressed sideways. This 

 is in the Lower- Ludlow mud-stone, olive-grey, laminated, and micaceous, associated 

 with the remains of an Orthoceras. It may possibly belong to either G. papilio or 

 G. stygia, if not to G. long a ; but the telson appears to have been longer than that 

 of G. papilio, and round-headed. This feature, which we observe also in a few 

 Scotch specimens, and in PL XI, fig. 1, may be a specific distinction. 



In the above-mentioned specimen (Cambridge Mus., &/36, PL XI, fig. 1) of two 

 abdominal segments, with a style and a stylet in good preservation, convex and not 

 injured by pressure, the penultimate segment is smooth, but shows some traces 

 of oblique lines ; the ultimate is quite smooth and cylindrical ; the telson (style) is 

 attached by an apparently rounded articulation ; and the stylet much resembles 

 some of those formerly referred to G. robusta. The telson tapers slowly, is smooth, 

 convex along the middle, was about 36 mm. long originally, and is bordered by a 

 slightly-raised rim. The stylet, like a broad sharp blade, about 20 mm. long, 

 also has its edges rimmed. The joint for the telson-head is not well-exposed, but 

 seems to be round and hollow. The place of attachment for the left stylet is not 

 distinguishable, owing perhaps to a lateral shift in the position of these appen- 

 dages. This specimen, preserved in dark-grey sandstone, micaceous and slightly 

 calcareous, with part of an internal cast of an Orthoceras, is from Benson Knot, 

 and is labelled " C. inornatus ;" but the evidence of this specific relationship is 

 supported only by its having been found in the same rock, and by its size suiting 

 the large form referred to " C. inornatus " (but probably G. stygia) in the 

 Cambridge Museum (J/35, PI. XI, fig. 1). This specimen is very much like the 

 caudal appendage of C. stygia, but it has a round-headed telson. 



PL XII, figs. 2 a, 2 b. Brit. Mus., No 45154. In the black shale of Lesma- 

 hago. Slimon Collection. Right valve outwards, broken in front; the other 

 partially visible. Delicately striate. Seven body-segments traceable, four exposed 

 beyond the valve ; obscure lattice-ornament on the third and fourth from the cara- 

 pace. Style and stylets nearly perfect, but modified by little roundish pits due to 

 decomposition. 



