THEODORI ICHTHYOSAURUS TRIGONODON. 41 



to a higher or a lower level by a fault. The veins discovered bej'^ond 

 the " Letten Kluft," in the Schreckengebirge, are so different from 

 those worked in the vicinity of Pribram, that the supposition of 

 their being continuations of the latter appears to be unwarranted. 



The alluvial deposits in the Litawka Valley are interesting from 

 the fact of their having been profitably washed for gold in the 1 6th 

 century. The auriferous rock, however, from which the allux-ium 

 was derived is still undiscovered. [Count M.] 



Description of the gigantic Ichthyosaurus trigonodon in the 

 Banz Museum, together with a Synoptical account of the species 

 q/IcHTHYOSAURUS in the same Collection. By Carl Theodori. 

 Fol. Munich, 1854. With 4 large Lithograph Plates illustrating 

 the fossils of the natural size. Pp. 95. 



[Beschreibung des kolossalen Ichthyosaurus trigonodon in der Lokal- 

 Petrefacten-Sammlung zu Banz, &c.] 



The remains of the Ichthyosaurus trigonodon described in this 

 Memoir, and particularly the almost perfect skull and jaws (6 feet 

 6 inches in length), are so important and instructive from their great 

 size and good state of preservation, that they were esteemed fully 

 worth the expense of the elegantly printed folio Memoir and the 

 four . gigantic lithograph plates (two of them 30y by 40 inches, and 

 the other two 30| inches by 8 feet !) by which they have been illus- 

 trated at the cost of the Archduke Maximilian, the proprietor of the 

 Banz Museum. 



Pages I to XIII of the work contain introductory remarks, a short 

 sketch of the lias formation at Banz, and an account of the finding 

 of the Ichthyosaurus trigonodon, the description of the teeth and 

 bones of which occupy the succeeding pages 1-40. 



The other species of Ichthyosaurus from the lias of Banz which 

 are noticed in this work, with descriptions of some of the most im- 

 portant portions of the skeletons, are the — 



Ichthyosaurus communis, Conyb., p. 42. 



tenuirostris, Conyb., p. 42. 



var. sinuatus, Theod., p. 50. 



acutirostris ?, Owen, p. 52. 



hexagonus, nov. sp., p. 55. 



planartus, nov. sp., p. 57. 



crassicostatus, nov. sp., p. 60. 



macrophthalmus, nov. sp., p. 64. 



ingens, nov. sp., p. 69. 



The relative proportions of the several bones of the skull and 

 trunk are further illustrated by two comprehensive synoptical tables. 



The Plates I. & II. exhibit two views of the cranium of the Ichth. 

 trigonodon of the natural size ! PI. III. is devoted to the illustration 

 of numerous bones of the same species. PL IV. comprises charac- 

 teristic bones of the other species of Ichthyosaurus from the lias of 

 Banz. [T. R. J.] 



vol. XI. part II. E 



