CALYMENE BLUMENBACHI. 135 



la. Calymene blumenbachi, auct., var. hov. drummuckensis. Plato XVII, 



fig. 14; plate XVIII, figs. 1—4. 



1851. Calymene blumeribachii, Salter, Quart. Journ. Geol. Soc, vol. vii, p. 172, pi. ix, figs. 1 a, 1 b. 



1854. Calymene blumenbachi, M'Coy (e. p.), Svnops. Pal. Foss. Woodw. Mus., p. 165. 



1873. Calymene blumeribachii, Salter (e. p.), Cat. Camb. Silur. Foss. Woodw. Mus., p. 77. 



1879. Calymene blumenbachi, Nicholson and Etheridge (e. p.), Mon. Silur. Foss. Girvan, fasc. ii, 



p. 140, pi. x, figs. 2 — 5 (non fig. 6). 

 1899. Calymene blumenbachi, Mem. Geol. Surv., Silur. Rocks Brit., vol. i, Scotland, pp. 524, 526 



(non cet.). 



Remarks. — The specimens from the Drummuck beds attributed to G. blumenbachi 

 by Nicholson and Etheridge (lor. eit.) are quite distinct from the typical Wenlock 

 form, as the examination of a large series of specimens indicates. They cannot, 

 however, be referred to either of the varieties allportiana, Salter, or caractaci, 

 Salter, though they are somewhat allied to the latter; and they are also separable 

 from G. senaria, Salter (e. p.) (= planimarginata), on account of the strongly-raised, 

 rounded, frontal border as well as other features. 



Description. — The head-shield is parabolic and pointed in front, like G. caractaci, 

 but the frontal border forms a strongly-rounded elevated rim as in typical examples 

 of G. blumenbachi, and the marginal furrow is deep and narrow, as in C. senaria, 

 auct. (non Salter). The glabella is longer than wide, but has a broader base than 

 < '. caractaci owing to the lateral projection of the large basal lobes which are situated 

 more than their diameter apart. The glabella is very slightly contracted in front 

 of them (not so suddenly as in C. blumenbachi), the axial furrows bending inwards 

 a little. The posterior lateral furrows are strongly bifurcated inwardly (well seen 

 in casts). The second lateral lobes are rounded and intermediate in size between 

 the anterior and posterior lobes, thus differing from all the types of C. senaria. 

 There is a buttress opposite them. The anterior lobes are small but distinct, and 

 are not overhung by the frontal lobe as in C. blumenbachi. The frontal lobe is 

 much shorter, narrower, and less swollen than in the typical specimens of the 

 latter. The axial furrows are slightly sigmoidal, not straight as in G. caractaci, 

 but agreeing with G. blumenbachi. The eye is opposite the second lateral lobe. 

 The fixed cheek has a width along the posterior margin about equal to the basal 

 width of the glabella. The surface of the head is coarsely but uniformly and closely 

 granulated, all the grannies being of equal size; and there is a low median tubercle 

 on the neck-ring. In G. blumenbachi there are scattered tubercles on the glabella. 



There appears to be no distinctive feature in the thorax ; and the pygidiuna is 

 indistinguishable from the typical 0. blumenbachi which Salter has well illustrated. 1 

 It may be remarked that the pleurae do not correspond with the axial ring- 

 even at the anterior end of the pygidiuna. The pleural furrows are only visible 

 1 Salter, 'Mon. Brit. Trilob.,' pi. viii, fig. 8c, pi. ix, figs. 1 b, 2 6. 



