ANNIVERSARY ADDRESS OF THE PRESIDENT. Ixix 



his paper " on the Geological Structure of the Alps, Apennines, and 

 Carpathians," Sir R. Murchison fully explained the triassic character 

 of the San Casciano beds, — an explanation which is now confirmed 

 by the more recent discoveries of Merian and others on the northern 

 flanks. 



To M. E. Renevier of Lausanne we are indebted for a geological 

 memoir on the Perte du Rhone and its vicinity. The author was 

 induced to undertake this work by the reflection, that, however often 

 this curious phaenomenon had been visited and quoted by geologists, 

 no special description of it had yet been given, nor any geological 

 map of it published on a scale sufliciently large to understand the 

 details. After referring to De Saussure for an account of the scene, 

 the author describes the different formations which are visible at this 

 locality resting regularly and conformably on each other in an almost 

 horizontal position. These formations are. Diluvium, Molasse, Upper 

 Chalk, Gault, and the Aptian and Trigonian formations below the 

 Gault, the two latter belonging to the Neocomian system. The 

 lowest bed, in which is cut the narrow passage where the Rhone is 

 almost lost to sight in dry weather, is the Caprotina limestone. The 

 vertical and horizontal distances are given in the sections in their 

 natural proportions. 



Two memoirs by M. Bosquet of Maestricht, published in the 

 second volume of the " Memoirs of the Committee for the Geological 

 Map and Description of the Netherlands," are deserving of notice in 

 connexion with secondary geology. The first is an account of some 

 new Brachiopods from the Maestricht beds. The fossils described 

 are, two new Cranics, C. comosa and C. Bi'edai ; the former is ex- 

 tremely rare, and only the lower valve has been as yet discovered ; 

 Argiojpe Davidsoni, Rhyncora plicata and R. KonincM. The second 

 memoir is of far greater extent, and is entitled " The Fossil Crustacea 

 of the Cretaceous Formation of Limburg." With the exception 

 of a few species of Cirripedes and some few Decapods, the work is 

 devoted to a description of the numerous Entomostraca abounding 

 in this formation. Some of these, like Bairdia subdeltoidea^ are so 

 universally distributed throughout formations of different ages, that 

 their geological value as a means of distinguishing strata is subservient 

 to their importance in a natural-history point of view ; several of the 

 other cretaceous forms also are still found living in the Mediterranean 

 and other seas. With regard to the genus Cy there, the most abundant 

 of all, M. Bosquet in this work describes thirty-four new species from 

 the cretaceous formation of Limburg, in addition to thirteen already 

 described by him in 1847 from the Maestricht beds. He adds that 

 he is also acquainted with about 114 species in the diff^erent beds of 

 the tertiary formation. The species described are all beautifully 

 figured, and some of the forms represented are of a curious and un- 

 usual character. Many are identical with, those already figured and 

 described by Mr. R. Jones in his " Monograph on the Entomostraca 

 of the Cretaceous Formation of England," published in 1849 by the 

 Paleeontographical Society. 



Prof. Bornemann, in his " Account of the Lias Formation in the 

 VOL. XI. e 



