PROFESSOR OWEN ON THE BELEMNITE. 
81 
as compared with those of the Nautilus, yields another proof of the constancy of the 
laws of organic correlation ; the very numerous, small, and comparatively simple 
tentacula of the Nautilus, which illustrate the principle of vegetative or irrelative 
repetition, being associated with an essentially inferior type of Cephalopodal organ- 
ization, into which an internal shell, a thick muscular mantle, pallial fins, and an 
ink-secreting apparatus do not enter. 
The cephalic arms of the existing species of Onychoteuthis present at the present 
day the highest grade of organization that has been observed in these characteristic 
prehensile instruments of the Cephalopoda. The great specimen captured by Banks 
and Solander off Cape Horn in the first voyage of Captain Cook, offers the best ex- 
ample of this formidable prehensile structure, since, not only were the extremities of 
the two long tentacula beset with hooks, but all the eight normal arms supported a 
double alternate series of uncinated acetabula. 
But in comparing the different forms of Cephalopods that have successively ap- 
peared and perished since the deposition of the lias to the present time, we do not 
find that the above most complex organization of the cephalic arms has been attained 
by or through progressive gradations, typified by the organization of intermediate 
forms : the ancient Belemnites manifested the uncinated armature as perfectly as the 
most formidable of existing Onychoteut hides. Nor were true Calamaries, with un- 
cinated arms, absent in those primeval seas, which were tenanted by living Belem- 
nites, Ammonites, and other extinct forms of Cephalopoda. The existence of naked 
Cephalopods of the family Teuthidas in the oolitic secondary formations, has been for 
some years demonstrated by the well-preserved and recognizable remains of the ink- 
bag, the gladius or horny pen, and the horny hooks developed from the acetabula of 
the cephalic arms. 
These singular fossils have been elucidated by the minute and accurate descrip- 
tions of Dr. Buckland*, and have elicited some beautiful remarks from the same 
eloquent writer in his Bridgewater Treatise^. They have been noticed and described 
by Zeiten, by V. Meyer, and Count Munster, from the lias schale of Aalen and 
Boll, and from the Solenhofen slate. The impression of an entire Onychoteuthis 
with the double series of hooks belonging to the eight short arms, nearly in their 
natural position, is figured in the Sixth Livraison of M. D’Orbigny’s ‘ Paleontologie 
Franqaise,’ 8vo, now in course of publication, under the name of Celceno speciosa , 
assigned to it by Count Munster. These hooks very closely resemble those of the 
Belemnites Owenii, but their base is rather less recurved, and they are more closely 
arranged : the fleshy part of the arms is not preserved ; but they were evidently 
shorter in proportion to the mantle than in the Belemnite. 
In conclusion, if we compare the Belemnite as now restored;};, not conjecturally, 
but by observation of phenomena, with the known existing forms of the Di branchiate 
* Proceedings of the Geological Society, 1829. + Vol. i. p. 303. J PI. VIII. 
MDCCCXLIV. M 
