ST. GALL. 113 



helvetica and Deikii] and two oaks (Quercus sclerophyllina and 

 cld'ina) flourished upon the drier and more distant land. If we 

 trace the brook to the place where it falls into the Miocene sea, 

 we come upon a brackish-water formation, which is recognizable 

 at once by the softness of the rock and its bluish colour. It is 

 about 15 feet thick, and must have originated from an extremely 

 fine mud. Together with the leaves and a few land Mollusca 

 (Helices and Auricula oblongd), which were swept down to the sea 

 and buried in its mud, we find thousands of a small brackish- 

 water animal (Paludina or Bythinia acuta), and in the uppermost 

 portion numerous cockles (Cardium hispidum], whole families of 

 clamshells (Chama gryphina, Lam.) and Diplodontae (D. rotun- 

 data], and here and there a few scattered oysters (Ostrea cras- 

 sissima). This brackish-water stratum overlies a deposit con- 

 taining numerous shells of Venus and Lutraria, which no doubt 

 hollowed out their dwelling-places in the mud ; and still lower 

 we meet with a layer of Turritella and Pandora. The soft marl 

 found in the brackish water is covered by a pebble-bed about 

 14 foot thick, which offers us the traces of a rich marine fauna 

 that lived among the pebbles. Attached to and among these 

 rounded stones are tubicolar Annelides, small corals, and nume- 

 rous Vermeti ( V. intortus)-, and within the fragments of limestone 

 are many living bivalves (G astro chance, Saxicavce, Sphenia, and 

 Pholades) which there formed a dwelling, whilst others sheltered 

 themselves in the tubes and passages formed by the boring 

 Mollusca, such as the Petricolce, Gastranff, young Lima, and 

 Mactrce, which we now find in the interior of these stones. 

 Among the pebbles we see whole colonies of Turbos (T. murica- 

 tus) and Murices (M. trunculus and vaginatus), and numerous 

 species of -Pleurotoma, Fusus, and Buccinum. Shining cowries 

 (Cyprcea sanguinolentu), curious Xenophora (X.Deshayesi), beau- 

 tiful Ancillarics and Columbella , and species of Mitra, Oniscia, 

 and Cassis are also discovered if we carefully search this friable 

 rock. Favourable conditions were here afforded for the deve- 

 lopment of Veneridse (Venus multilainella, Cytherea crassissima, 

 and Lucinopsis Lujonkairei) , of Pholadomyce (P. arculata), Do- 

 sinicE (D. Adansoni), and Diplodontce. For so rich a fauna there 

 must have been at this spot a sheltered bay, into which at first 

 a brook discharged itself, the direction of which subsequently 



VOL. II. 1 



