. Le royaume des animaux : organisé après son organisation ; formant une histoire naturelle des animaux et d'introduction à l'anatomie comparée. Zoologie. Classe 2. PTEROPODES. 335 connexion avec septa de leur sliells^, a provoqué, le hke genres que nous venons de traiter, à être organisé dans la série des céphalopodes ; mais cette classification nécessite d'être confirmé par plus de nombreuses observations avant d'être considéré comme réglé. Linnteus Gmclin* et placé l'espèce connue dans tlicir temps dans le genre Nautilus, M. d'Orbigny, qui a étudié plus attentivement les lias que n'importe qui

• Contributeur: Library Book Collection
• ID de l’image: RN4W40
• Taille du fichier: 7,2 MB (240,4 KB Téléchargement compressé)
• Autorisations: Modèle - non | Propriété - non
• Dimensions: 2386 x 1048 px | 40,4 x 17,7 cm | 15,9 x 7 inches | 150dpi

Informations supplémentaires

Cette image appartient au domaine public, ce qui signifie que le droit d’auteur a expiré ou que le titulaire du droit d’auteur a renoncé à ses droits. Les frais facturés par Alamy couvrent l’accès à la copie haute résolution de l’image.

Cette image peut avoir des imperfections car il s’agit d’une image historique ou de reportage.

. The animal kingdom : arranged after its organization; forming a natural history of animals, and an introduction to comparative anatomy. Zoology. Class 2. PTEROPODES. 335 connection with tlie septa of their sliells, has occasioned them, hke the genera which we have just treated of, to be arranged in the series of Cephalopods; but this classification requires to be confirmed by more numerous observations before it can be considered as settled.* Linnteus and Gmclin placed the species known in tlicir time in the genus Nautilus, M. d'Orbigny, who lias studied them more carefully than any one else, makes an order of them, which he calls Foraminiferes, because the cells communicate only by holes; and he divides them into families from the manner in which the cells are arranged. AYhen the cells are simple, and disposed spirally, the shells constitute his Ilelicostec/ties, which are subdivided; for, if the whorls of the spire envelope each other, as is particularly the case with the Camerines, he names them Helicostegues nautiloides ; if the whorls do not cover themselves, they are H. ammonoides ; and if the whorls rise up, as in the greater number of univalves, they are his //. turbinoides. The family Stycostegues is known by the simple cells being, as it were, threaded on a single straight, or slightly curved axis. When the cells are disposed in two alternate rows, they are then the Enallostegues. If the cells are gathered together in small numbers, and heaped up in a globular shape, the family is the Agathlstegues. Lastly, in the Entomostegues, the cells are not simple, as in the preceding families, but are subdivided by transverse partitions, so that a section of the shell tliscovers a sort of trellis-work. THE SECOND CLASS OF MOLLUSCA.f THE PTEROPODES. They swim, like the Cephalopods, in the sea, but cannot fix themselves there, nor creep, from want of feet. Their organs of locomotion consist of fins onlj', placed at each side of the mouth. The species known are of sm

Recherche dans la banque de photos par tags

• bookauthorwe
• bookcentury1800
• bookdecade1860
• booksubjectzoology