HARDWICKE'S SCIENCE-GOSSIP. 



253 



cuttle-fishes, of wliicli no fewer than a hundred dif- 

 ferent kinds arc known to geologists, from the Lias 

 to the Tertiary beds. Tiiey are not found in strata 

 of the latter age, their places being occuioied by 

 allied forms more nearly related to existing species. 

 Side by side with the coiled Ammonites, the Belem- 

 nites roamed the waters of the Oolitic and Greta' 

 ceous seas. Unfortunately, little more is usually 

 preserved than the " guards " — the solid parts of the 

 animal we call Belemnite. A few specimens which 

 have been unusually well preserved, however, give 

 us a clue to their structure. Thus, Belemnites 

 puzosiaiiv.s (flg. 17S) is one of these. The solid part, 

 which is so common amongst us, swelled out 

 into a thin investing, funnel-shaped cavity, in 

 which lay a series of walls, like those which sepa- 

 rate the chambers of a nautilus. An air-tube, or 

 siphaicle, ran down one side of these chamber-walls 

 and connected them together, exactly as a similar 

 air-tube connects the chambers of fossil and recent 

 species of nautilus. This pile of chamber walls was 

 conical, and is called the phragmacone. In fig. 179 

 a short thick species of Belemnite from tlie Oolite, 

 this phragmacone is seen imbedded in the guard. 



Fig. 179. Belemniteis (ihhrpjniitns, showing phragmacone 

 111 guard, from Oolite. 



Very frequently, however, especially in the species 

 so abundant in the chalk formation, this upper 

 portion of the Belemnite is hollow, owing to the 

 delicate nature of the chambers, and where the 

 Belemnite has been imbedded in flint nodules (as is 

 very often the case) the carbonate of lime structure 

 has been replaced, and this hollow filled up with 

 silex, as in fig. ISO, where the outlines of the original 

 chambers may still be seen. In this form they are 

 well known among the quarrymen and boys as 

 "pinnacles." The "guard" of the Belemnite, it will 

 be seen, corresponds to the "mucro" of the ordi- 

 nary cuttle-bone. The last chamber is rarely 

 preserved. It seems to have thinned off into a kind 



of horny sheath, ^and was sufiiciently capacious to 

 contain the visceral organs. Over all there perhaps 

 was wrapped a leathery integument, binding 

 head, body, and bony "guard," or belemnite, to- 

 gether. These guards vary in appearance very 

 considerably, much of which may have been due to 

 the different stages of growth, or difference of sexes. 

 Sometimes it is scarcely an inch longer than the 

 phragmacone, and at others it may be ten inches. 



m 



'ii I Mill 



Fig:. 180. 

 Cast of Phfdgtiiacnnp, showing Fig, 181. B. miirronutus, 

 chambers, from the chalk. from the chalk. 



These ancient cuttle-fishes, or Belemnites, appear 

 to have swarmed the seas in perfect shoals, for frag- 

 ments of Liassic limestone may sometimes be seen 

 thickly entangled with them— to use a figure of 

 poor Hugh Miller's, — " as if a boarding party had 

 hastily thrown down their pikes ! " The shallower 

 parts of the sea seem to have been their favourite 

 haunts, and thus far they contrasted with the Am- 

 monites, which appear to have loved tlie deeper and 

 clearer water. The Belemnites were doubtless fur- 

 nished with "ink-bags," like their modern repre- 

 sentatives, and thus were enabled to cloud the 

 water with an inky discharge whenever danger 

 threatened. Specimens have been found in which 

 the "guard" had been broken during the lifetime 

 of the animal, and had been repaired by a new 

 growth. But the inexorable limits of space tell us 

 we have said enough to show that the Belemnites 

 have no affinity whatever with the hypothetical 

 " Thunder-bolts." J. E. Taylok. 



NATURAL HISTORY FOR RUSTICS. 



TENNYSON, with that prevision of a future 

 which is at least not destitute of possibility, 

 describes, in " Locksley Hall," how he beheld the 

 agonies and convulsions of nations in the coming 

 age, from w^hich was slowly eliminated the glories 

 of a time of unsurpassed prosperity. There was 

 conflict such as the world never, had seen, but it 



