86 Remeivs — Symonds Records of the Rocks. 



not quite prepared to admit or agree with the author in removing the 

 Lower Llandovery out of the Lower Silurian, its affinity with the 

 Caradoc or Bala series being so close both on stratigraphical as well 

 as palaeontological grounds. Out of the 560 species known in the 

 Caradoc, and 126 in the Lower Llandovery, ninety-two are common, 

 no less than eighteen species of Corals, thirty-six Brachiopoda, ten 

 Gasteropoda, nine Crustacea, six Cephalopoda, etc., being common 

 to the two formations ; only eleven species are really peculiar to the 

 Lower Llandovery rocks. We know of no physical break between 

 the Lower Llandovery and Caradoc, though between it and the 

 Upper there appears to be no doubt whatever. 



The reader will do well to carefully read this chapter apart from 

 the abstract question of stratigraphical subdivision. It is admirably 

 and clearly written. 



In Chapter vi., 60 pages are devoted to th« Upper Silurian Eocks. 

 These pages are really a manual of Upper Silurian Geology and 

 Geography, or Topographical Geology, interspersed with so much 

 general and local history and lore that every class of reader may 

 be interested. The rocks are described in ascending order, their 

 geographical distribution and historical associations being highly 

 instructive. The section devoted to the Wenlock rocks is suggestive, 

 clear, and like the previous chapters, a "vade mecum" to the tourist 

 and Silurian student. The points of interest, and localities where 

 good sections and rich fossil-grounds can be seen, are depicted 

 with a local knowledge possessed by few geologists. The Ledbury 

 rocks and passage-beds are debatable ground where the speculative 

 geologist may revel in disquisition and doubt as to the more minute 

 subdivisions in the upper series. Here too the Ganoid and 

 Placoid fishes for the first time attest their presence in Britain, 

 fragments of many genera [Pteraspis, Auchenaspis, CephaJaspis, 

 ScapJiaspis) occurring in varied abundance. These Ledbury or 

 passage rocks connect the Upper Ludlow shales with the base of 

 the Old Eed Sandstone; and where junction sections are seen, 

 they become of extreme interest. Tlie earliest determined fossil 

 plant-remains in the British Islands come from the passage -beds 

 at Bodenham, west of Ledbury, and may have belonged to the 

 first or earliest Lycopodiaceous plants, the ancestors, indeed, of the 

 Devonian and Carboniferous Lycopods. For most interesting matter 

 upon the Upper Silurian rocks the reader must consult the "Records." 

 Four plates of very characteristic fossils and many woodcuts 

 accompany the Silurian division of the volume. 



The Old Eed Sandstone Chapter (vii.) adds little, physically, to 

 the hitherto known history and extension of these rocks. The Old 

 Eed, however, in Herefordshire and Monmouthshire, in its triple 

 division, is indeed a grand feature. In the Vans of Brecon and 

 Carmarthen, which rise nearly 3000 feet above the sea, their 

 northern flanks and outcrop afford scenery of surpassing boldness 

 and grandeur. 



The rapid development of genera and species of the fossil fishes, 

 as well as their classification and distribution through the rocks 



