18 BRITISH CAMBRIAN TRILOBITES. 



and nearly cylindrical, and bears a small tubercle at its base; basal lobes not 

 seen. Cheeks steeply inclined downwards from the glabella, greatly contracted 

 forwards and reduced in front of the glabella to a narrow strip. The marginal 

 furrow is narrow posteriorly and widens greatly towards the front. 



Tail subquadrate, with a wide margin which is nearly uniform in width. Axis 

 forms about half the width of the whole tail, is slightly constricted in front of 

 the middle, and terminates bluntly in a rounded obtuse angle. It bears a 

 prominent median tubercle or elevation and is marked on each side by three 

 lateral furrows, of which only the first pair meet, in the centre. Axial furrows 

 deep. Lateral lobes greatly narrowed behind the axis, where they are confluent 

 \\ ith each other. 



Head 2 - 5 — 4 mm. long, 8 - 5 — 4'5 mm. wide; tail 3 mm. long, 5 mm. wide. The 

 specimens are somewhat distorted. 



This form belongs to Tullberg's series Eegii. The head, indeed, is scarcely to 

 be distinguished from that of Agnostus rex, Barrande, 1 itself, but the axis of the 

 I ail does not show the terminal expansion so characteristic of that form. In this 

 respect it agrees with A. regulus, Matthew, 2 with which indeed it may prove to be 

 identical. A. regius, Sjogren,"' is another closely allied form, the tail of which, how- 

 ever, is nearer to that of A. rex than to that of either A. cambrensis or A. regulus. 



Synonymy. — The form here described is that which was originally figured and 

 described by I licks under this name. Subsequently, in 1872, he figured another 

 form under the same name ; but this is clearly distinct and is identical with 

 A. integer (Beyr). 



Types. — The originals of Hicks' s figs. 11 ami 12 are in the Sedgwick Museum, 

 Cambridge. 



Ih>ri::<in and Locality. — Harlech Series: St. David's. 



(h) Fallaces. 

 15. Agnostus integer (Beyrich). Plate II, fig. 10. 



1845. Battus integer, Beyrich, CTeber einige bolimische Trilobiten, p. 44, fig. 1!». 



is Id. Hallux integer, />'. orion, />'. affinis, It. cuneifer, pars, Barrande, Notice preliminaire, pp. 14—18. 



L847. Mesospheniscus cuneifer, Viplnrrhina rotundata, l>. triplicata, D. orion, D. umbonata, D. sirius, 



D. elliptica, l>. n*/><rii!<t, I), selenophora, J), monas, D. affinis, I>. cristata, Peronopsis integra, Hawle 



and Corda, Prodrom., pp. 46—50, 115, pi. iii,figs. 22, 23, pi. vi, fig. 62. 

 L852. Agnostus integer, Barrande, Systenae silurien, vol. i, p. 900, pi. xlix. 



1 Barrande, Syst. Silur., vol. i, \>. '.tux, pi. xlix. 



! G F. Matthew, Trans. N. V. A.cad. Sri., vol. xv (1896), p. 213, pi. xvi, fig. 1. 



s Sjogren, G-eol. For. Sfcockh. Forli., vol. i (1872), p. 7<>, pi. v, fig. (>. See also Linnarsson, ibid. 



. iii. 1,1. xv. lius. 9, 1<> 



