160 M. Duval on the Belemnites of the Lower Cretaceous 
attracted the attention of naturalists ; commentators have 
supposed they recognise them in the Lyncurium described 
by Theophrastus, or in the Dactylus idaeus of Pliny; and 
howsoever the case may be with these obscure indications, 
we can, with certainty, trace the observations of which these 
bodies have been the object as far back as Agricola. The 
list of authors who have successively treated of them from 
the first half of the fifteenth century up to our own era, is of 
very great length. It is only, however, in later times that ob- 
servers have agreed as to the nature and origin of these re- 
mains of animals no longer existing, and, in order to do away 
with all uncertainty in this respect, not only the profound 
researches of many zoologists into their internal structure. 
was necessary, but the discovery, besides, of a Belemnite ex- 
panded at its anterior extremity like the bone of a cuttle-fish, 
and still enclosing in a cavity thus formed an ink-bag similar 
to those of the Cephalopodes of our own seas. This fact, which 
M. Agassiz has determined in two fossils found by a lady at 
Lyme-Regis, effectually proves that Belemnites are not spines 
of Echini, or the cutaneous appendages of some other echino- 
derm, as Klein supposed upwards of a century ago, and as M. 
Raspail contended only a few years since, but really internal 
shells belonging to a molluse whose organization must offer 
many points of analogy to the cuttle-fish (Loligo) of the pre- 
sent era. This result will not be seriously questioned by any 
one who is capable of appreciating at their just value the re- 
searches on this subject, published by Miller, by our learned 
associate M. de Blainville, and also by Voltz, an observer as 
exact as he was laborious, whose recent death we have to la- 
ment. The nature of Belemnites was no longer, therefore, a 
problem requiring a solution ; but the study of the differences 
these fossils present among themselves was but little advanced, 
and much uncertainty prevailed regarding the distinction of 
the species,—an interesting question to the zoologist, but still 
more important to the geologist, who might desire to find in 
those remains characters capable of fixing the date of the de- 
posits in which they are found embedded. 
In order to throw light on this part of the history of Belem- 
nites, it was not enough to compare and describe the varia- 
