Adaptations des C&phalopodes. 113 
Octopodes 
Ommatostrephidae 
Belemnoteuthidae 
Oegopsides 
aaase 
Dibranches 
Orthoceratidae 
Nautllöider 
Tetrabranches 
2. Considerons, maintenant, dans le m&me ordre d’idees, I’ Evo- 
Iution des Organes les plus interessants pour nous, c’est-&-dire: 
l. Bras, 
2. Nageoires, 
3. Ooquille. 
3. Nous aurons, pour Evolution des Bras: 
Octopus 8 bras 
Ömmatostrephes 10 bras inegaux 
Belemnoteuthis 10 Be 0) 
Nautilus 90 al )) 
1) G. A. MAnTELL, Petrifications and their teachings, Londres, 1851, 
p. 459. — G. C. ORICK, The Arms of the Belemnites, in: Proc. Malacol. 
Soe., 1907, Vol. 7, p. 270. — K. A. von ZITTEL, Grundzüge der Palä- 
ontologie, Munich, 1910, p. 514. 
2) R. Owen, On the Structure and Homology of the Cephalic Ten- 
tacles in the Pearly Nautilus, in: Ann. Mag. Natur. Hist., 1843, Vol. 12, 
p- 305. — L. E. GRIFFIN, Notes on the Tentacles of Nautilus pompilius, 
in: Johns Hopkins University Circulars, 1898, Vol. 18, p. 11. — 
L. E. GRIFFIN, The Anatomy of Nautilus pompilius, in: Mem. Nat. Acad. 
Sc., Washington, 1898, Vol. 8, p: 113. — A. WILLEY, Zoological Re- 
sults based on Material from New Britain, New Guinea, Loyalty Islands 
and elsewhere, collected during the years 1895, 1896 and 1897, Cam- 
bridge, 1902, p. 800. 
Zool. Jahrb., Suppl. XV (Festschrift für J. W. Spengel Bd. ]). 5 
