REMOPLEURIDES CORRECTUS. 37 



anterior end where the eye is widest forty or a few more; there are about twenty 

 rows to a millimetre, and as the eye measures 11 — 12 mm. along its curved surface 

 there are some 8000 lenses in it. Salter gave a very diagrammatic representation 

 of the eye of R. colbii, which is useless for comparison as no minute description 

 accompanied it. The lower lid or rim round the eye is a prominent narrow band 

 marked off above and below by a deep groove. The free cheek is not well seen in 

 this specimen. 



The thorax so far as it is preserved appears to have the same characters and 

 proportions as B. colbii. Only four segments are present. 



In another specimen showing only the occipital ring and base of the glabella, 

 the ornamentation of the former is seen to be indistinguishable from that of 

 B. colbii. 



The eye of Bemojpleurides appears to have never been minutely described, and 

 Lindstrom, 1 perhaps for this reason, omits it from his list of Trilobites in a classifi- 

 cation based on the form and structure of their eyes. Apart from these specimens 

 of B. colbii referred to and described by Nicholson and Etheridge, I have seen no 

 other representatives of this genus from Drummuck. 



Dimensions (type specimen). — 



Length of glabella (including tongue) . . 1 2 , -5 mm. 



Width ,, between eyes . . 10 - ,, 



Length of tongue, about . . . 5*0 ,, 



Width „ at base . . 7*0 „ 



Distance between bases of eyes . . . 7"- r » ,, 



Collection.— -Mrs. Gray (f. M.). 



Horizon and Locality. — Drummuck Group (U. Bala) : Drummuck. 



1879. Remoplat rides barrandii, Nicholson and Etheridge, e. p., Mon. Silur. Foss. Girvan, Ease. ii. 



p. 151, pi. x, figs. 14 — 16 (non fig. 13, nee pi. xi, fig. L6). 

 1899. Be mopleur ides barrandei, e. p., Mem. Greol. Surv., Silur. Rocks Brit., vol. i, Scotland, pp. 509, 



514, 673. 



Specific Characters. — Glabella subcircular, with two pairs of oblique lateral furrows 

 (of which the anterior pair is sometimes merely recognisable as a pair of indistinct 

 pits). Anterior tongue measures from two thirds to three fourths the width of the 

 glabella and is nearly equal to it in length ; expands slightly towards an abruptly 



1 Lindstrom, ' Kongl. Svensk. Vet. Akad. Hand!.,' vol. xxxiv, No. 8 (1901), p. 26. 



