98 TRILOBITES OF GIRVAN. 



the furrows of the head-shield, this species bears a considerable resemblance to 

 L. wesenbergensis, Schmidt. The pygidium also is of the same type, though 

 differing in minor details. AVe may consider them as closely allied forms. 



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



Horizon and Localities. — Dnvmmuck Group (U. Bala) : Drummuck ; Starfish 

 Bed, Thraive Glen. 



3. Lichas (Corydocephalus) scutalis, Salter, 1873. Plate XIV, figs. 3, 4. 



1873. Lichas scutalis, Salter, MS., Cat. Camb. Silur. Foss. Woodw. Mus., p. 130. 



1877. Lichas verrucosus, Woodward, Cat. Brit. Foss. Crust., p. 43. 



1878. Lichas scutalis, Edgell, MS., Cat. Camb. Silur. Foss. Mus. Pract. Geol., p. 84. 

 1891. Lichas verrucosus, Woods, Cat. Type Foss. Woodw. Mus., p. 147. 



1899. Lichas ambigua (Barraude), Mem. Geol. Surv., Silur. Rocks Brit., vol. i, Scotland, pp. 532, 689. 



1901. Lichas scutalis, Reed, Geol. Mag. [4], vol. viii, p. 5, pi. i, figs. 1 — 4. 



1902. Lichas (Corydocephalus) scutalis, Reed, Quart. Jouru. Geol. Soc, vol. lviii, pp. 71, 82. 



The species L. scutalis is represented from the Lower and Middle Llandovery 

 Beds of Girvan by pygidia and head-shields. The pygidia agree essentially with 

 the type from the Wenlock of Dudley, 1 except in having the axis rather shorter 

 and, consequently, the triangular post-axial piece and ridge rather longer ; the 

 forked posterior points of the margin are also rather more elongate and acute. 

 But these are trifling differences, perhaps pointing to a local variety. The 

 head-shields show all the typical features. These specimens were recorded in the 

 Survey Memoir 2 as " L. ambigua, Barrande." 



Collection. — Mrs. Gray. 



Horizons and Localities. — Mulloch Hill Group (L. Llandovery) : Mulloch Hill ; 

 Craigens. Saugh Hill Group (M. Llandovery) : Newlands ; Woodland Point. 



4. Lichas (Corydocephalus) wesenbergensis, Schmidt, 1885. Var. ? Plate XIV, 

 fig. 2. 



1857. Lichas laticeps, Nieszkowski (rion Angelin), Mon. Trilob. Ostseeprov. in Archiv. Liv. Est. 

 Kurlands, ser. 1, vol. i, p. 577, pi. vi, fig. 20 (e.p.). 



1858. Lichas sexjmnctatus, Hoffmann, Siimmt. Trilob. Russl. (Verb. Miner. Gesell., Jalirg. 1857-58), 

 p. 24, pi. i, figs. 4—8 (?). 



1885. Lichas (Arges) wesenbergensis, Schmidt, Rev. Ostbalt. Silur. Trilob., pt. ii, p. 44, pi. vi,. 

 figs. 1—4. 



1901. Lichas (Hemiarges) wesenbergensis, Giirich, Neues Jabrb. f. Min., Beil. Bd. xiv, p 526. 



1902. Lichas wesenbergensis, Reed, Quart. Journ. Geol. Soc, vol. lviii, p. 71. 



^eed, 'Geol. Mag.' [4], vol. viii (1901), p. 5, pi. i, figs. 1—4. 



2 'Mem. Geol. Surv., Silur. Rocks Brit.,' vol. i, Scotland (1899), Appendix, p. 689. 



