CERATIOCARIS RUTHVENIANA. 49 



given iu the 'Brit. Pal. Foss.,' p. 137, nor with that in the 'Ann. Mag. Nat. 

 Hist.,' L c, but is based on the original specimens, and not on the restored figure 

 in the ' Brit. Pal. Foss.' The diagrammatic figure annexed by Mr. Salter to his 

 note on C. inornata in the ' Catal. Camb. Sil. Foss. Mus. Univ. Cambr.,' 1873, p. 

 178, is used also in connection with two other species at p. 16 and p. 164; and 

 is much like the form which we recognise as C. Halliana. 



G. inoniaia approaches G. papilio in form, but is smaller and otherwise 

 distinct. There is one from Lesmahago, Lanarkshire, in dark coloured shale, 

 calcareous on its edges, B. M. 59648 (PI. X, fig. 6), near to G. papilio in form, 

 but measuring 34 X 13 mm., and one from Benson Knot, Kendal, Westmoreland, 

 in hard grey sandstone, micaceous, and slightly calcareous, B. M. 44342 (PI. X, 

 fig. 2), measuring 35 X 14 mm. These proportions are different from those of G. 

 papiUo. These two are rather smaller than M'Coy's original G. inornata, which is 

 about 50 X 20 mm., but have the same proportions, the normal length being 2\ 

 the height ; whilst G. papilio is larger and has less height in proportion, the 

 length being only twice the height, or even less. 



PI. X, fig. 3. Cambridge Museum b/o. " Upper Ludlow ;" Benson Knot, 

 Kendal. This was figured by M'Coy, ' Brit. Pal. Foss.,' pi. 1 B, fig. 4, and 

 mentioned by Salter, ' Catal. Cambr. Foss.,' p. 177. It is in hard, dark-grey, 

 micaceous sandstone, slightly calcareous on the edge. There is no eye-spot, the 

 marks being adventitious. 



18. Ceeatiocaeis Ruthveniana, T. B. J. ^- H. W., 1886. PI. X, fig. 6. 



1885. Cehatiocaius inoenata, T. R. J. S{ R. W. Tliird Eeport Pal.Phyll.,p.34.5; 



Geol. Mag., 1885, p. 460. 



1886. — EuTHVENiANA, — Fourth Eeport, p. 232 ; Geol. 



Mag., 1886, p. 459. 



From among the specimens formerly called G. inornata we have removed one of 

 the specimens found at Benson Knot, and marked 44342 in the British Museum 

 (PI. X, fig. 6), being decidedly diflFerent in outline (more ovate), though somewhat 

 similarly marked with longitudinal strige. It might well be named C. Ruthveniana, 

 in memory of the old geological collector w^ho laboured for very many years in the 

 Kendal district for Professor Sedgwick and others. 



The carapace is nearly of the shape of half an egg cut lengthwise ; almost 

 straight above, elliptical below, and boldly rounded behind; probably rounded 

 with a blunt point, nearly on the dorsal line, in front. Longitudinally striate. 



7 



