454: Trof. T. 8terry Hunt — On Cambrian and Silurian. 



two genera, Paradoxides and Agnostus. In 1826 appeared a 

 memoir by Dalman on the Palceadce or so-called Trilobites; 

 which, was followed, in 1828, by his classic work on the same sub- 

 ject — " Ueber die Palaeaden oder so-genanten Trilobiten," 4to. with 

 six plates, Leipzig. In these works were described and figured, 

 among many others, two genera — Olentis, which included Para- 

 doxides, Brogn., and Battue, including Agnostus of the same author. 

 Meanwhile, Hisinger was carefully studying the strata in which 

 these Trilobites were foand in Gothland, and in the same year (1828) 

 published in his AntecJcningar, or Notes on the Physical and Geo- 

 gnostical Structure of Norway and Sweden, a coloured geological map 

 and section of these rocks as they occur in the county of Skaraborg; 

 where three small circumscribed areas of nearly horizontal fossil- 

 iferous 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; S. Alum-slates; 5. Orthoceratite-limestones ; 4. Clay- 

 slates. By a curious oversight the colours on the legend are wrongly 

 arranged 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 ortho- 

 ceratite-limestones (5). 



In 1837 Hisinger published his great work on the organic re- 

 mains of Sweden, entitled LetJicea Suecica (4to. with forty-two plates). 

 In this he gives a tabular view, in descending order, of the rock- 

 forraations, and of the various genera and species described. The 

 rocks of the areas just noticed appear in his fourth or lowest divi- 

 sion, under the head of Formationes transitionis, and are divided as 

 follows : 



a. Strata calcarea recentiora Gottlandise. 



i>. Strata schisti argillacei. 



c. Strata schisti aluminaris. 



d. Strata calcarea antiquiora. 



e. Strata saxi arenacei. 



The succession thus given was however erroneous, and probably, 

 like the mistake in the legend of the same author's map just men- 

 tioned, the result of inadvertence, the true position of the alum- 

 slates (c) being between the older limestone (d) and the basal sand- 

 stone (e). This is shown both by Hisinger's map of 1828, and by 

 the testimony of subsequent observers. In Murchison's work on the 

 Geology of Eussia in Europe, published in 1845, there is given 

 (page 15 et seq.) an account of his visit to this region in company 

 with Prof Loven, of Ohristiania ; which, with figures of the sections, 

 is reproduced in the different editions of Siluria. The hill of Kinne- 

 kuUe on Lake Wener is one of the three areas of transition rocks 

 delineated on the map of Hisinger above referred to. Besting upon 

 a flat region of nearly vertical gneissic strata, we have, according to 

 Murchison: 1. a Fucoidal Sandstone; 2. Alum-slates; 3. Bed Ortho- 

 ceratite Limestone; 4. Black Graptolitic Slates; the whole series 

 being little over 1000 feet in thickness, and capped by erupted 



