REM0PLEUR1DES NANUS. II 



strongly. Tlio median notch on the posterior margin between the free ends of 

 the second pair is generally larger and deeper than that between the free ends of 

 the two pairs. The axis is represented by a pair of large rounded or subtriangular 

 nodules almost meeting in the middle line and nearly half the width of the 

 pygidium. A faint median elevation is generally noticeable behind them. 



This Girvan species of Remoplewides differs from B. laterispinifer in the tuber- 

 culation of the neck ring and base of the glabella, the presence of furrows on the 

 glabella, the ornamentation of the axial rings and pleurae, the presence of a con- 

 spicuous median tubercle on the eighth ring, and the characters of the pygidium. 



Only the head-shields of B. salteri are known, and the points of resemblance 

 to the Girvan form have been mentioned. None of the Waterford specimens 

 reach the size of the majority of the Girvan examples, but this is perhaps not a 

 matter of much importance. B. tuberculatus, Reed, is also allied, but not so closely 

 as B. salteri. The only other species of Remojrteuridex which closely resembles the 

 Scottish one is B. linguatus, Ruede., 1 from the Trenton Conglomerate of Rysedorph. 



There are a few specimens of Bemopleurides from Minuntion which appear to 

 be attributable to this species and variety, though their preservation in limestone 

 gives them a slightly different appearance. The shape and characters of the head- 

 shields are identical, the basal tuberculation being often visible, but the lateral 

 furrows are obscure or not traceable. The occipital segment and thorax have 

 the specific ornamentation ; the enlargement of the seventh thoracic pleurse is 

 marked, and the tubercle on the eighth axial segment is also present, while the 

 pygidium seems to be identical; but no perfect examples have come under my 

 notice. 



Collections. — Mrs. Gray (f. M.) ; Museum of Practical Geology ; Edinburgh 

 Museum ; Woodwardian Museum. 



Horizons and Localities. — Balclatchie Group (Llandeilo) : Dow Hill ; Ardmillan. 

 ? Stinchar Limestone Group (Llandeilo) : Minuntion. 



8. Remopleurides cf. nanus (Leuchtenberg), 1843. Plate VI, figs. 16, 17. 



1843. Nileus nanus, Herz. v. Leuchtenberg, Thierreste v. Zarskoje selo, p. 13, pi. i, figs. 12, 13. 

 1858. Nileus nanus, Hoffmann, Verliandl. Miner. Gesell. St. Petersb., pi. vii, figs, 4 a, h. 



Remopleurides nanus, Yolbortli, Verliandl. Miner. Gesell. St. Petersb., p. 133, pi. xii, figs. 6 — 10. 

 1861. Remopleurides nanus, Eichwald, Letli. Ross., p. 1446. 

 1894. Remopleurides nanus, Schmidt, Eev. Ostbalt. Silur. Trilob., Abth. iv, p. 88, pi. vi, figs. 34, 35. 



Bernards. — The genus Bemopleurides is represented from Craighead by some 

 imperfect head-shields which seem comparable to the species B. nanus, Leuchtenb., 

 occurring in the Lower Ordovician of the Baltic provinces. There are three pairs 



1 Ruedemann, 'Bull. 49, N.T. State Mus.' (1901), p. 56, pi. hi, figs. 21—29. 



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