127 



ferences as will lead to the formation of three species : B. fusiformis, 

 -B. cylindriformis, and B. coniformis. The first of these, B. fusiformis^ 

 Plate VIII. Fig. 13, is by no means a common fossil, except in a very 

 mutilated state. Its general figure is fusiform. A receptacle for the 

 alveolus exists in the upper part, in the form of a reversed cone, from 

 the point of which the body of the fossil again swells, and continues of 

 a compressed roundish shape, with a longitudinal sulcus, for an inch or 

 two, when it terminates with a tapering point. The figure which is here 

 given is from a specimen, which is perfect only as far as the shading is 

 carried, the upper part in outline being added from a fossil in the pos- 

 session of Mr. George Humphries, of Leicester-square. I believe this 

 species is chiefly found near to Stonsfield, and in the adjoining parts o t 

 Oxfordshire. 



B. cylindriformis, Plate VIII. Fig. 10 and 14, is, I suspect, very 

 rarely found in a state so perfect as the other species are. Fig. 14 is a 

 fragment of one of this species, so split, as to give a very fair view of 

 the alveolus, which is filled with white spathose matter : the belemnite 

 itself is formed of the darkest spar that I have seen in any specimen of 

 this fossil. Fig. 10 is part of one of the cylindrical species; but roundish 

 at both ends ; I suspect, from being rolled by the water. This fossil is 

 here shown chiefly for the purpose of your noticing a very small linear 

 channel, which is continued from the point of the alveolus, longitu- 

 dinally through the rest of the spathose substance. This is the pipe, or 

 canal, of which M. Walch speaks, in his account of this fossil. 



B. coniformis. Plate VIII. Fig. 15, shows the most common form of 

 this fossil : the specimen is so broken, as to show also the form and 

 situation of the concarnerated shell, in its alveolus. The chief varieties 

 observable in this species are those depending on their colour, and their 

 being more or less suddenly pointed, as Figures 11 and 12. 



They are found of various sizes ; from less than that of a goose-quill 

 to a foot in length, and two inches in diameter. Baier says : " Maximi 

 belemnitae raro deprehenditur integri : habeo autem ingentia fragmenta^ 



