. Cephalopoda. Cephalopoda. The gladius has the typical juvenile form of Oegopsida (Figures 132, 133). It ends posteriorly in a flat cone and is not yet surrounded by the muscular mantle, which is still attached only at the margin. The mantle sac is rounded posteriorly, and the fins form rounded lobes with a narrower base. The fins are connected posteriorly by a distinct transverse edge which occurs also in other young Metateuthoidea and is reinforced during embryonic life by the transverse part of Hoyle's organ (cf. Vol. II, Plate VII; also Figure 88). The fins are otherwise completely separa
. Cephalopoda. Cephalopoda. The gladius has the typical juvenile form of Oegopsida (Figures 132, 133). It ends posteriorly in a flat cone and is not yet surrounded by the muscular mantle, which is still attached only at the margin. The mantle sac is rounded posteriorly, and the fins form rounded lobes with a narrower base. The fins are connected posteriorly by a distinct transverse edge which occurs also in other young Metateuthoidea and is reinforced during embryonic life by the transverse part of Hoyle's organ (cf. Vol. II, Plate VII; also Figure 88). The fins are otherwise completely separated in the middle. The mantle sac is still without ventral corners, and there are no distinct adhesion 290 surfaces (funnel bonds) on the funnel. The head shows the typical form of early larvae (Figure 88) and the olfactory organ is also situated in its typical position as a flat, low, oval papilla. The arms are of different length, the ventral arms the shortest. The third pair is already as long as the first, but not as long as the second pair. The tentacles are the longest and their distal third bears 2 rows of small suckers. Each arm bears a zigzag row of suckers. Luminous organs are FIGURE 140. Young stage of Abraliopsis morrisi from the Naples plankton, collected on 9 September 1910. 5x. Numerous similar specimens from Naples and Messina are available, but not so well preserved. The specimen was drawn after preservation. Note the form of mantle and fins, translucent gladius, funnel appa- ratus, head, arm apparatus, chromatophores and especially the "anlagen" of the olfactory and luminous organs (dotted rings). Compared with this young larva, the following stage ( Figure 140) represents a distinct progress. Head and body still resemble those of a young Loligo, i. e. the typical young forms of the Metateuthoidea. The arms, however, are much longer, which is characteristic for the larvae of the Enoploteuthinae and differs from those of the Loliginidae (but
Size: 1489px × 1678px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionbiodivers, booksubjectcephalopoda
