1853.] BRODIE — FOSSIL INSECT IN KIMMERIDGE CLAY. 51 



the beautiful forms of " Old Red " ichthyolites published in the works 

 of Agassiz, informs me that he has twice visited Shetland ; his first 

 visit having been so far back as 1803, and his last in 1852, or after 

 an interval of forty-nine years ! He states that to the north of 

 Lerwick, the sandstones and flags pass downwards into conglomerates, 

 which rest upon mica-slate, gneiss, granite, and hornblende rocks. In 

 the cliff hills, on the contrary, which are the spine of the southern 

 projection of the chief island, clay-slate, with occasional beds of lime- 

 stone, also reposes on the primary rocks. Thus, we are presented 

 in the Shetland Isles with a series of the same rocks which abound 

 throughout the northern Highlands of Scotland, the oldest primary 

 rocks being succeeded first, in some places, by clay-slates and lime- 

 stones which may partially represent the Silurian rocks, and in others 

 by conglomerates, flagstones, and sandstones, the last of which, dipping 

 off from, and overlying all the other rocks, are the light-coloured 

 sandstones in which the fossil plants of Lerwick occur. 



Sustained by the opinions of such experienced geologists as Drs. 

 Fleming and Traill, both of them acquainted with the structure of 

 Shetland, I continue in the belief, that the sandstone of Lerwick is 

 of the same age as the rocks of Elgin, Burghead, Tarbet Ness in 

 Ross, and Dunnet Head of Caithness, all of which Prof. Sedgwick 

 and myself described as constituting the uppermost member of the 

 Old Red Sandstone*, and as overlying the Caithness flagstones with 

 their numerous ichthyolites. 



Whether, through the discoveries of fossils, this rock may even- 

 tually be classed as the bottom of the Carboniferous rather than 

 as the summit of the Old Red or Devonian group, is a matter of 

 interesting speculation, now that the land plants from Lerwick and 

 the Telerpeton of Mantellf from Elgin have given characters to 

 these sandstones which were unknown when our classification was 

 suggested. 



The order of superposition is, however, clear and undisputed; and 

 the strata in question form the uppermost band of a connected series 

 of conglomerates, flagstones, schists, and sandstones which constitute 

 the Old Red Sandstone as defined by my associate and myself. 



2. Notice of the Occurrence of an Elytron of a Coleopterous 

 Insect in the Kimmeridge Clay at Ringstead Bay, Dorset- 

 shire. By the Rev. P. B. Brodie, M.A., F.G.S. 



Although the occurrence of a single Elytron of a Coleopterous 

 Insect scarcely appears at first sight worthy of attention, yet, since 

 the discovery of remains of Insects in any stratum or fresh locality 

 may lead other observers to obtain additional forms of Insect life 

 from rocks as yet unproductive in this respect, and thereby give 

 us an insight into the characters of those which flourished at such 



* Trans. Geol. Soc. Lond. 2 Ser. vol. iii. p. 125, 1828. For a description of 

 the strata of Dunnet Head and the Orkneys, see a previous memoir by myself, in 

 Trans. Geol. Soc. Lond. 2 Ser. vol. ii. p. 314. 



t See Quart. Journ. Geol. Soc. vol. viii. p. 97 et scq. 



