PLATE 27.
NERVOUS SYSTEM AND SENSES.
- Fig. 1, Nervous system of Coronula diadema, seen from the ventral
surface.
- A, infra-œsophageal ganglion; two pairs of rather small nerves,
arising from the dorsal surface, cannot be here shown.
- B, supra-œsophageal ganglion, double.
- C, ophthalmic ganglion, single.
- D D, eyes, as believed to exist.
- a, three pairs of nerves, running to the gnathites and olfactory
pouches;
a′, nerve rising from the collar, running towards the mandibles.
- b, single medial nerve, running to the great transverse
muscle, extending across the upper part of the stomach.
- c, collar-nerve or chord, uniting the infra- and supra-œsophageal
ganglions.
- d, great splanchnic nerve, here spread laterally out, but
properly running along the sides of the upper part of
the prosoma, and therefore under the collar-nerve;
d′, plexus by which this nerve is connected with the
supra-splanchnic nerve, e.
- e, supra-splanchnic nerve, rising from the collar, almost in
contact with the supra-œsophageal ganglion;
e′, small nerve rising from the end of the supra-œsophageal
ganglion, and running to the adductor and surrounding muscles.
- f, f, pair of great nerves (antennular), distributed over the
sack and shell.
- g, chord (in appearance single), uniting the supra-œsophageal
ganglion with the first (C), or ophthalmic ganglion.
- h, small medial nerve, running to near the adductor muscle.
- i, nerve supposed to run from the ophthalmic ganglion to the
eye.
- k, small nerve, rising from the main ganglion (A), between
r1 and r2, or the nerves running to the first and second
pairs of cirri.
- œ, position of the œsophagus.
- r1 nerve entering the first cirrus.
- r2, r3, r4, r5, r6, nerves entering the five succeeding
pairs of cirri.
- s, nerve entering the probosciformed penis.
- 2, nervous system of Balanus tintinnabulum; letters of reference
as in fig. 1.
- 3, acoustic sack of Balanus tintinnabulum.
- 4,””Coronula diadema.
- 5, eye of Balanus tintinnabulum; i, nerve coming from the
ophthalmic ganglion; D, eye itself.