. Cephalopoda. Cephalopoda. the muscular mantle already adheres to the funnel at their position, and a distinctly bordered stripe appears on each side of the funnel soon after 189 hatching. External funnel adductors are present already at this stage. Except for the closing of the primary lid into a cornea, the head shows the typical characters of the larvae of Decapoda: it is dorsoventrally flattened, the eyes are directed anteriorly, and the flat, oval olfactory papillae are situated on the ventral side. :i87). FIGURE 87. Median section through an older embryo of Loli g o v u Ig a ri s (diagr
. Cephalopoda. Cephalopoda. the muscular mantle already adheres to the funnel at their position, and a distinctly bordered stripe appears on each side of the funnel soon after 189 hatching. External funnel adductors are present already at this stage. Except for the closing of the primary lid into a cornea, the head shows the typical characters of the larvae of Decapoda: it is dorsoventrally flattened, the eyes are directed anteriorly, and the flat, oval olfactory papillae are situated on the ventral side. :i87). FIGURE 87. Median section through an older embryo of Loli g o v u Ig a ri s (diagrammatic). Approximately 30X. Ho — Hoyle's organ (median part); Ss — shell sac; Go — "anlage" of gonad; Si — rudiment of siphuncle; — parts of coelom; Gv — genital vein; Hz — heart; Ms — mantle septum; Mm — muscular mantle; Mv - mantle cavity (ventral); Af - anus; Ni — kidneys; Do - yolk; Ma - stomach; Gg — gastric ganglion; Bl — caecum; Td — ink gland; Vc — vena cava; Dr — funnel gland; Tk — funnel valve ("anlage") Tr — funnel; St — statocyst; Sn — blood sinus; Vg — visceral ganglion; Pd — pedal ganglion; Cg — cerebral ganglion; Sr — subradular organ; Ao — anterior aorta; Ra — rhachis part of shell sac; Md — dorsal mantle cavity; Nk — neck cartilage; Oe — esophagus; Gd — poison gland; Rd — sac of radula; Ob — upper buccal ganglion; Ub — lower buccal ganglion; Ok — upper jaw; Uk — lower jaw; 11 - inner lip; Al — outer lip; Mu — mouth. Compare with Figure 59 on p. 142. This is the typical structure of an embryo of Dibranchiata, but the cone part of the shell sac is already flattened and reduced, the siphuncle is hardly indicated, and the shell sac is divided into flag (or cone) part and rhachis (or proostracum) part. This section is important for the morpho- logical interpretation of such stages and shows a very instructive picture of the topography of Dibranchiata. The yolk sa
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Keywords: ., bookcentury1900, bookcollectionbiodivers, booksubjectcephalopoda
