FOSSIL INVERTEBRATED ANIMALS. 



483 



which De Montfort had formed into a genus called by him 

 Bellerophon. One of the characters which he assigns to this 

 genus is the having of smooth septse, pierced by a siphunculus. 

 This is one of the many errors published by this author. Two 

 of these species, one from De Montfort's own collection, were 

 in possession of M. de France. Suspecting that they were 

 single-chambered, this gentleman sawed one of them trans- 

 versely, and found, in fact, that it was rolled on itself like a 

 nautilus, but had no septae ; so that instead of entering into 

 the division of the polythalamous cephalopodes, this genus 

 should be placed in that of the monothalamous, near the argo- 

 nautae. Our figure, from Mr. Sowerby's work, was found in 

 Westmorland. 



Several species of Orthoceratites are found in England, 

 as may be seen by the work of Mr. Sowerby. The following 

 are the characters assigned to this genus in the " Mineral Con- 

 chology" — shell straight, or but little curved, fusiform, with 

 septae traversed by a siphunculus ; the edge of the septae 

 smooth, with one or two slight undulations. 



In his voyage to the North Pole, M. de Buch found, near 

 Drontheim, a black limestone filled with orthoceratites, in the 

 neighbourhood of Christiania. Some of them are several feet 

 in length. They are plane on one side, convex on the other, 

 and traversed by a siphunculus throughout their entire length. 

 There is reason to believe that these tubes were cylindrical or 

 oval, and that the plane part has been destroyed, which has 

 happened to many ammonites, &c. M. de Buch says, that, 

 at Konigsberg, he has seen some which were three or four feet 

 long. 



Orthoceratites have been found in a variety of other loca- 

 Hties throughout Europe, and even in Siberia. 



By the word Belemnites is designated a petrified shell, of a 

 conical, straight, and elongated form, whose structure appears 

 to have much analogy with that of the ammonites. It is com- 

 posed of two distinct parts, the case and the alveolus. The 



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