168 



TRILOBITES OF GIRVAN, 



a longer and narrower central lobe to the glabella and more elongate bicomposite 

 lobes. There is also a faint trace of the posterior part of the axial furrows as in 

 L. lulbiceps, and the occipital lobes are subquadrate as in that species. The whole 

 head-shield measures 12*25 mm. in length, of which the glabella occupies 10'5 

 mm.; the width of the latter at its anterior end is 8*75 mm., and at its base 9 mm. 

 between the posterior ends of the axial furrows on the outside of the occipital 

 lobes. The bicomposite lobes, which do not converge strongly posteriorly, measure 

 5'75 mm. long by 3 mm. wide. The width of the base of the central lobe between 

 the inner angles of the occipital lobes is 4 - 5 mm. 



We can hardly separate this form from L. grayi or its variety scoticus, but it- 

 offers certain interesting deviations from the typical proportions of the Wenlock 

 examples of the former, and they point in an opposite direction to those exhibited 

 in the variety scoticus. 



Collection— -Mrs. Gray. 



Horizon and Locality. — Mulloch Hill Group (L. Llandovery) : Mulloch Hill. 



LIST OF SPECIES. 



Family Agnostid^e. 



Agnostus agnostiforntis (M'Coy). 

 girvanensis, sp. nov. 

 perrugatus, Barr. 

 ,, tardus, Barr. 



Fa mil ii Harpedid^:. 



Harpes flanagani, Portl. ? 



sp. ind. (a) to (c). 



Family Trinucleim:. 



Tri nucleus buchlandi, Barr. 



? macconochiei, Eth. and Nich. 

 „ subradiatus, sp. nov. 



„ sp. mil. (a) to (g). 



Ampyx depressus (Aug.) ? 



,, drummuclcensis, sp. nov. 



horn el, Eth. and Nich. 

 „ incur vus, sp. nov. 

 „ macallumi, Salt. 



luainniillatus, var. austini, Portl. ? 

 cf. foveolatus, Ang. 

 cf. scanicus (Ang.) 

 Dionide lapworthi, Eth. and Nich. 

 richardsoni, sp. nov. 



Family Olenid^:. 



Triarthrus becki, Gi - een ? 

 Apatolcephalus, sp. 



Bemopleurides barrandei, Eth. and Nich. 

 ,, (Teratorhynchus) bicoruis. 



sp. nov. 

 „ colbii, Portl. ? 



,, correctus, sp. nov. 



dorsospiiufer, Portl. 

 ,, longicostatus, Portl. 



,, salteri, Reed, var. nov., 



girvanensis. 

 „ cf. nanus (Herz. v. Leucht.) 



,, cf. platyceps, M'Coy. 



Shumardia scotica, sp. nov. 

 Salieria primseva, Wyv. Thorn. 

 Telephus fr actus, Barr. 



Family AsAPHICa:. 



Asaphus (Isotelui) gigas, De Kay? 



,, ,, instabilis, sp. nov. 



,, sp. ind. 

 Stygina latifrons (Portl.) 

 Cyclopyge armata (Barr.). 

 ,, rediviva (Barr.). 



