474 THE POPULAR SCIENCE MONTHLY. 



nature. On close examination, the saucer-shaped partitions were proved 

 to be all perforated at one point, and, the perforations being situated 

 exactly in the same line, the chambers were seen to be traversed by a 

 canal or siphuncle, which thus connected the smallest or apical cham- 

 ber with the largest. There is nothing like this in the vegetable 

 world; but an exactly corresponding structure is met with in the shells 

 of two kinds of existing animals, the pearly Nautilus and the Spirula, 

 and only in them. These animals belong to the same division the 

 Cephalopoda as the cuttle-fish, the squid, and the octopus. But they 

 are the only existing members of the group which possess chambered, 

 siphunculated shells ; and it is utterly impossible to trace any physio- 

 logical connection between the very peculiar structural characters of a 

 cephalopod and the presence of a chambered shell. In fact, the squid 

 has, instead of any such shell, a horny " pen," the cuttle-fish has the 

 so-called " cuttle-bone," and the octopus has no shell at all, or a mere 

 rudiment of one. 



Nevertheless, seeing that there is nothing in nature at all like the 

 chambered shell of the Belemnite, except the shells of the Nautilus and 

 of the Spirula, it was legitimate to prophesy that the animal from 

 which the fossil proceeded must have belonged to the group of the 

 Cephalopoda. Nautilus and Spirula are both very rare animals, but 

 the progress of investigation brought to light the singular fact that, 

 though each has the characteristic cephalopodous organization, it is 

 very different from the other. The shell of Nautilus is external, that 

 of Spirula internal ; Nautilus has four gills, Spirula two ; Nautilus 

 has multitudinous tentacles, Spirula has only ten arms beset with horny 

 rimmed suckers ; Spirula, like the squids and cuttle-fishes, which it 

 closely resembles, has a bag of ink which it squirts out to cover its 

 retreat when alarmed ; Nautilus has none. 



No amount of physiological reasoning could enable any one to say 

 whether the animal which fabricated the Belemnite was more like 

 Nautilus, or more like Spirula. But the accidental discovery of Be- 

 lemnites in due connection with black elongated masses which were 

 certainly fossilized ink-bags, inasmuch as the ink could be ground up 

 and used for painting as well as if it were recent sepia, settled the 

 question ; and it became perfectly safe to prophesy that the creature 

 which fabricated the Belemnite was a two-gilled cephalopod with 

 suckers on its arms, and with all the other essential features of our 

 living squids, cuttle-fishes, and Spirulm. The paleontologist was, by 

 this time, able to speak as confidently about the animal of the Belem- 

 nite as Zadig was respecting the queen's spaniel. He could give a very 

 fair description of its external appearance, and even enter pretty fully 

 into the details of its internal organization, and yet could declare that 

 neither he, nor any one else, had ever seen one. And, as the queen's 

 spaniel was found, so happily has the animal of the Belemnite ; a few 

 exceptionally preserved specimens having been discovered which com- 





