392 Structure of the Belenmite. 



riosity ; I seai'ched my cabinet, but in vain, to find specimens 

 of the same kind. I endeavoured, but with similar success, to 

 procure some from Ireland, and it was not till last autumn 

 (1820), when I was in that country in company with Lord 

 Compton, that I was enabled to procure the necessary supply. 

 In the extensive lime-quarries of Mr. Farrel, of Larne, I 

 pointed out to the labourers the belemnites imbedded in flint, 

 which were quite familiar to them, and for a trifling gratuity 

 an abundant quantity was sent me in a day or two to Belfast. 

 On submitting them to the acid, almost all have afforded some- 

 thuio- extremely interestmg and curious, and have opened up 

 a source of investigation which may probably lead to unex- 

 pected results." 



" The means I employed was to dilute muriatic acid with 

 four or fi:ve waters, and perhaps this was too rough an appli- 

 cation for the very delicate and mmute fibres which were often 

 exposed to it, as I found in too many instances, that, after the 

 specimens were dried, the flinty arborisations would sometimes 

 fall to pieces." 



Mr. Allan next describes ten specimens of the belemnite, 

 seven of which had thus been dissected, as it were ; referring to 

 seme beautiful figures by Mr. R. R. Greville, with which his 

 observations are illustrated. In one of them, marked No. 3, 

 the conical alveolus " fills up entirely the base of the belem- 

 nite ; tlie trace of its circle being lost in the substance of the 

 flint. At its apex there is a delicate capillary process appended. 

 This is the process, which proceeds from the apex of the cone 

 to that of the belenmite. I have found it always extremely de- 

 licate, and it sometimes fell to pieces by its own weight. There 

 are also some of the little branches of flint which have occupied 

 the pores or perforations alluded to." 



♦' No. 4. This beautiful specimen resembles the first I ob- 

 tained. Alongside of tl:e cone are those tubes and capillary 

 vessels connected with the cone, and with the sides of the be- 

 lemnite, and entangled in lace-like v,ork, small, irregular, glo- 

 bular masses, all connected by the most slender fibres." 



In order to prevent No. 5 fi'om falling to pieces, "the dissolu- 

 tion of the carbonate was watched, and stopped, when the speci- 

 men was sufficiently displayed ; the vessels which have here 



existed, have much vhe character of organization ; they twist 

 and range about, quite like the gut of an animal. Still, as we 

 see so little resemblance between this and the other specimens, 

 we cannot but hesitate to attribute it to an origin which be- 

 speaks uniformity and regularity. 



" No. G. This specimen is singular ; it has evidently been 

 broken off" at each end : the cone, of which only a small portion 



i-emains, 



