38 TRILOBITES OF GIRVAN. 



truncated front end, and is more or less strongly bent down. Surface of glabella 

 and tongue coarsely reticulate. Byes strongly curved, embracing sides of glabella ; 

 palpebral lobes narrow. Occipital ring arched and ornamented with subparallel 

 fine lines running from side to side and bent back in the middle. Free cheeks 

 triangular, with short genal spines ; half as wide as glabella, extending from neck 

 ring to base of tongue ; surface coarsely reticulate. 



Dimensions (type specimen). — 

 Length of head . . . . .4*5 mm. 



,, of glabella (without tongue) . . . 2*5 ,, 



Width of „ ( „ „ ) . . . -P0 „ 



,, of tongue at base . . . 3'0 ,, 



Remarks. — The specimen figured by Nicholson and Etheridge (op. cit., pi. x, 

 fig. 16) showing the free cheek, has the latter part displaced and shifted forwards 

 from its proper position ; but this fact is not mentioned in their description of it. 

 The real relation of the free cheek to the tongue of the glabella is the same as in 

 R. colbii. 



In the specimens of R. correctus from Dow Hill and Ardmillan, which are in the 

 state of casts, the anterior tongue seems to be rather longer and more expanded 

 towards the tip than in the typical Balclatchie examples ; the lateral furrows are 

 also rarely perceptible ; but I believe that these differences are mainly if not 

 wholly due to the state of preservation. 



Affinities. — R. correctus differs from R. barrandei as now limited (v. p. 31) by 

 the more subcircular and less transverse shape of the glabella, by the presence of 

 only two pairs of lateral furrows, by the reticulate ornamentation of the surface, 

 and by the shape of the anterior tongue. Of other species R. jentzschi, Pompecki, 1 

 seems the most closely allied, but the tongue in the latter is apparently shorter 

 and not expanded anteriorly. 



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



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

 Ardmillan. 



5. Remopleurides dorsospinifer, Portlock, 1843. Plate VI, fig. 6. 



1843. Remopleurides dorsospinifer, Portlock, Greol. Hep. Londond., p. 256, pi. i, fig. 3. 



1846. Eemopleurides dorsospinifer, M'Coy, Synops. Silur. Foss. Ireland, p. 43. 



1853. Remopleurides dorsospinifer, Salter, Mem. Geol. Surv., dec. vii, pi. viii, figs. 3, 4. 



1854. Remopleurides dorsospinifer, Morris, Cat. Brit. Toss., 2nd ed., p. 115. 



1867. Remopleurides dorsospinifer, Salter, in Murchison's Siluria, 4th ed., p. 206, pi. xlviii, fig. 25. 



Pompecki, ' Die Trilobitf. Ost-, West-Preuss. Diluv. (lesch./ 1890, p. 87, pi. i, figs. 31, a, b. 



