MISCELLANEA. 95 



of perfectly preserved dotted vessels. The author deduces as a cou- 

 clusion, that the coal must have been composed of thin layers of 

 vegetable matter scattered in a confused manner, and that no trunks 

 of trees, or any considerable portion of their branches, had anything 

 to do with its formation. — Sillimarts Journ., 2nd Ser., vol. i. p. ^O?. 



V. Remarks on Terebratula dipiiya. By M. d'Hombre 



FiRMAS. 



This singular form of Terebratula occurs in the neighbourhood of 

 Moscow (?) and Warsaw, in the Carpathians, in Switzerland, near 

 Verona and Belluno, in the Departments of Les Basses- Alpes, Drome, 

 Vaucluse and Ardeche, and near Gigondas, Baumes, and Berias in 

 the Neocomian series. The author describes six specimens, offering 

 every variety of form, from those which have a simple continuous 

 outline to others in which there is a perfect aperture through the 

 middle of the shell, and all of these varieties are either derived 

 from differences of age, or are such modifications as can only be 

 ranked amongst varieties of structure. From a comparison of these 

 and a multitude of other specimens in different cabinets, he comes 

 to the conclusion that the so-named Concha diphya, Colonna, Tere- 

 bratula cor^ Brug., T. deltoidea, Lamarck, T. triquetra, Park., T. un- 

 tinomia, CatuU., and T. diphya, Von Buch, form but one species, 

 and cannot be divided into three {T. antinomia^ T. dipTiya and 

 T. deltoidea) as recently proposed by CatuUo (Osserv. Geogn. 

 Zool., Padova, 1 84-0), for if any subdivision is made, we must esta- 

 blish at least ten species. M. Firmas also considers that Terebra- 

 tula pileuSy Brug., and T. triangulus, Lamarck (var. T. mutica, Ca- 

 tul.), described as species from the same formation as the former, 

 are really only rare varieties of the same. They appear to exist 

 only in the Veronese and Belluno beds. — Leonhard and Bronns 

 Jahrbuchfor 184*6, p. 117. 



VL On the Structure of the Orthoceratite. 



At a meeting of the French Geological Society on the 15th of De- 

 cember 1845, M. Defrance read the following communication with 

 regard to the Orthoceratite : — 



In a visit which I recently made at the Chateau of Aux, near 

 Nantes, I observed on a marble table the shell of an Orthoceratite 

 of unusual size and in remarkable preservation. Although cut slant- 

 wise, it was still more than a yard long, and nearly an inch (•945 

 inch) across in its middle part. In the portion of tiie shell pre- 

 served there were seventy-four simple concave chambers, the last of 

 which was something more than a foot long ; the rest were traversed 

 by a marginal siphuncle of rather large size. 



On the same table there was a portion of the extremity of another 



