BRITISH FOSSILS. 



s 



iEGLINA GRANDIS. 



Plate. IV. Figs. 7, 8. 



Diagnosis. ovalis, 2-S-uncialis, depressa, tuberculata, axe corporis 

 angusto ; cauda rotundata Imvi, laterihus unisulcaiis. 



Synonyms. JEglina grandis, Salter^ Siluria, 2nd ed., p. 53. Foss. 9, 

 fig. 6. Id. Mem. Geol. Surv., vol. iii. (ined.) pi. 12, fig. 11. 



DesGTVption. — Oval (rather depressed ?) If inch long ; head 

 more than two-fifths the whole length, with a large glabella without 

 lobes, covered with rather prominent tubercles. This character is 

 so remarkable in the genus that no long description is necessary to 

 enable us to recognize the species. The eyes are very large, as long- 

 as the head, and there appears to be a larger border beyond them 

 than usual in the genus. 



Body of six rings, the axis narrower than in most of the species, 

 broadest in front, contracted behind, where it scarcely equals the 

 pleurae in width. These are bent at the fulcrum, which is placed 

 rather more than one-third out from tlie axis in the front rings, and 

 nearly at half in the hinder ones. 



The tail is semicircular, and has rather a conical axis of two 

 joints, rather long in our figure 8, which I believe is the same 

 species. One obscure lateral furrow (the uppermost) is all that is 

 visible on the smooth sides. A distinct margin runs all round the 

 tail, neatly defined, but not by a broad or deep furrow. The shape 

 of the tail in fig. 7 is much rounded, and more than a semicircle. 

 In fig. 8 it has been compressed longitudinally, and has a shorter 

 aspect ; but I believe this is only due to compression in the slaty 

 rock. 



The largest specimen I have seen appears to have the fulcrum of 

 the pleurae further inwards, but agrees in other respects with the 

 remaining specimens ; at least it has the tubercular glabella, a 

 character in which our species difiers from all others. 



Of the two British species previously described ; JS'. mirahilis, 

 Forbes, has a parabolic and lobed smooth glabella. JE. major, 

 Salter, has a wide body axis, and two lateral furrows in the tail. 



All Barrande's species have a smooth glabella, and are very much 

 smaller than oars, except his speciosa, which has a very broad 

 axis and short marginal eyes. 



Locality. — Lower Llandeilo Flags (Arenig group ?), South 

 side of St. David's Head, Pembrokeshire. 



