Prof. C. Lapworth—Ballantrae Rocks of South Scotland. 23 
TABLE SHOWING THE RANGE OF THE BALLANTRAE GRAPTOLITHINA. 
Oy & 8 
wa ist -) a Ad 
S| 3 las|5e8|ho|ao | *, 
Aa el) cai ea ae alee 
; ; 
SPECIES, Seat eliaeen | sie Ibe. te 
ae|u=igglee|fe|ss]| 2 
s | SO |BC|SE| mal mal] 2 
mo os o- ro) <_< 
= aS | a SS = 
ale| S)e4i1e |e 
= e| a 
< Ay Pa 
Phyllograptus typus, Hall ... x x x x x x 
Tetragraptus bryonoides, H. sais Ke x x x xa exe 
i quadribrachiatus, Hi. 5K at | Xen XS ox x x x 
9 fruticosus, Hall peal eta lc x xe x x 
op Bigsbyi, Hall Dae iaaay 4. 09% x x x 
Didymograptus extensus H. aa cei aeeemmllieees i, || 25 x x x 
HA bifidus, H., Murchisoni, Beck.) x | x | x IK pan xx 
Oaryocaris Wrightii, Salt. .. ane melt x 
We have therefore in the foregoing facts a complete paleonto- 
logical demonstration of the theory that the local series of rocks to 
which the title of Ballantrae Series or ‘“‘ Ballantrae rocks ” has been 
applied, is in reality a complex of stratified, altered, and igneous 
rocks of very different geological ages: Arenig, Llandeilo, and post- 
Ordovician: the common facies of the pseudo-series being mainly 
the result of the common interfolding, alteration, and intrusion its 
rocks have undergone. The development of the natural order, 
inter-relationships and mode of alteration of this complex has 
yet to be worked out, and can only be satisfactorily accomplished 
by a mapping of the entire district, zone by zone, and band by 
band. When that work has been completed, it is by no means un- 
likely that fossiliferous zones of a yet higher antiquity may be 
detected; and that here it will be shown that, as elsewhere, the most 
extreme views held regarding the collective rock series may each 
have contained a certain proportion of the actual truth. 
Although the simple fact of this discovery of an Arenig fauna in the 
Ballantrae rocks has long been made known,® I have hitherto with- 
held the foregoing details, because of their vital bearing upon the 
general question of the true sequence of the Lower Paleozoic rocks 
of the Scottish Uplands. The present, however, appears to be the 
most natural time for their publication. The epoch-making memoir 
by Messrs. Peach and Horne on the structure of the N.W. High- 
lands in the Quarterly Journal of the Geological Society for August, 
1888, p. 378, has given the finishing-stroke in Britain to the antiquated 
ideas of the reliability of apparent stratigraphy in areas subjected 
1 Nicholson, 1872, Brit. Mon. Grapt. p. 97, etc. 
2 Hopkinson and Lapworth, Q.J.G.S. 1875, p. 635. 
3 Hall, Grapt. Quebec, 1865, pp. 56-57. 
* Coll Canadian Geol. Survey. 
5 Tullberg, Skanes Grapt. pt. i. 1882, p. 22, ete. 
6 Brégger, Die Silurischen Etagen 2 und 3, 1882, pp. 38-41. 
7 Lapworth, Geol. Dist. Rhabdophora, 1879, p. 23. 
8 Jukes-Browne, Historical Geology, 1886, p. 98. 
