10 TRTLOBITES OF GIRVAN. 



Horizon and Locality. — Camregan Group (U. Llandovery) : Bargany Pond 

 Burn. 



4. Harpes, sp. ind. (c). 



Remarks. — An imperfect limb from Aldons differs from the other Girvan 

 examples of th.o genus by the narrowness of the limb and its general shape. It is 

 strongly arched, and the ends bend inwards to a considerable extent, the arms not 

 being parallel. The limb is only 3 mm. broad, which is less than one-sixth the 

 width of the whole horseshoe. The lower surface has the shell preserved, and 

 scarcely shows any punctations, but a single row of larger pits lies inside the 

 rounded border, as in H. flanagani. IT. parvulus, M'Coy (' Contrib. Palreont.,' 1854, 

 p. 200, and ' Syn. Brit. Pal. Foss.,' p. 336, pi. Il, fig. 3), from the same horizon, 

 has a wider limb, but the type is too badly preserved for a thorough comparison. 



Collection. — Mrs. Gray. 



Horizon and Locality. — Stinchar Limestone Group (Llandeilo) : Aldons. 



Family Trtnucleiu^. 

 Genus TRINUCLEUS, Llwyd. 

 1. Trinucleus bucklandi, Barrande, 1846. Plate I, figs. 10 — 14. 



1846. Trinucleus bucklandi, Barrande, Not. Prelim., p. 31. 



1847. Trinucleus bucklandi, Corda, Prod. Mon. Bohm. Trilob., p. 39. 



1852. Trinucleus bucklandi, Ban-ancle, Syst. Silur. Bolu-me, vol. i, p. 621, pi. xxix, figs. 10 — 17. 

 1876. Trinucleus bucklandi, Armstrong and Young, Cat. West. Scot. Foss., p. 16. 

 ? - Trinucleus seticornis, Armstrong and Young, ibid., p. 16. 



1879. Trinucleus seticornis (Hisinger) var. bucklandi, Nicholson and Etheridge, Mon. Silur. Foss. 



Girvan, fasc. ii, p. 190, pi. xiii, figs. 13—20. 

 1899. Trinucleus bucklandi and T. seticornis, Mem. Geol. Surv., Silur. Kocks Brit., vol. i, Scotland, 



p. 524. 



Remarks. — This is an exceedingly common trilobite at Drummuck, and is largely 

 represented in most collections from this locality and also from Thraive Glen and 

 Lady Burn. It is this species which Nicholson and Etheridge named T. seticornis, 

 His., var. bucldandi, Barr. (M., fasc. II, 1870, p. 100, pi. xiii, figs. 13, 14 (?), 15, 16, 

 17 (?), 18 — 20), and they gave a careful and excellent description of the Girvan 

 form which only requires the addition of a few minor details. It is stated by them 

 ih.it the surface of the glabella is reticulate, and they give a figure (M., Inc. n't., 

 pi. xiii, fig. 17) which shows a coarse reticulate ornamentation. From the minute 

 examination of a very extensive series of specimens, many retaining the shell and 

 in excellent preservation, there can be no doubt that the surface of the glabella as 



