366 CAMBRIAN AND SILURIAN IN EUROPE. [XV. 



and Battus, including Agnostus of the same author. Mean- 

 while, Hisinger was carefully studying the strata in which 

 these trilobites were found in Gothland, and in the same year 

 (1828) published in his Anteckningar, or Notes on the Physical 

 and Geognostical Structure of Norway and Sweden, a colored 

 geological map and section of these rocks as they occur in the 

 county of Skaraborg ; where three small circumscribed areas of 

 nearly horizontal fossiliferous strata are shown to rest upon a 

 floor of old crystalline rocks, in some parts granitic and in 

 others gneissic in character. The section and map, as given 

 by Hisinger, show the succession in the principal area to be as 

 follows, in ascending order : 1. Granite or gneiss ; 2. Sandstone ; 

 3. Alum-slates ; 5. Orthoceratite-limestones ; 4. Clay-slates. By 

 a curious oversight the colors on the legend are wrongly ar- 

 ranged and wrongly numbered, as above ; for in the map and 

 section it is made clear that the succession is that just given, 

 and that the clay-slates (4), instead of being below, are above 

 the orthoceratite-limestones (5). 



In 1837, Hisinger published his great work on the organic 

 remains of Sweden, entitled Lethosa Suedca (4to, with forty- 

 two plates). In this he gives a tabular view, in descending 

 order, of the rock-formations, and of the various genera and 

 species described. The rocks of the areas just noticed appear 

 in his fourth or lowest division, under the head of Forma- 

 tiones transitions, and are divided as follows : 



a. Strata calcarea recentiora Gottlandise. 



b. Strata schisti argillacei. 



c. Strata schisti aluminaris. 



d. Strata calcarea antiquiora. 



e. Strata saxi arenacei. 



The succession thus given was, however, erroneous, and proba- 

 bly, like the mistake in the legend of the same author's map 

 just mentioned, the result of inadvertence, the true position 

 of the ahun-slates (c) being between the older limestone (d) 

 and the basal sandstone (e). This is shown both by Hisinger'a 

 map of 1828, and by the testimony of subsequent observers. 

 In Murchison's work on the Geology of Russia in Europe, 



