NERVOUS SYSTEM OF AURELIA AURITA. 
573 
Fit*-. 11. End of fibre nearest to margin : near its commencement is seen a fusiform 
o o 
nucleated swelling. 
Fig. 12. The next part of the fibre. It exhibits two lateral brandies, which take 
the direction of the muscular fibres, and soon become lost amongst 
them. 
Fig. 13. The central part of the fibre with its interpolated nerve-cell. A small 
nucleus adheres to one end of the cell, which perhaps belongs to a sheath 
represented by the clear surrounding of the cell. 
Fig. 14. The next succeeding portion of the fibre. Here there are two such nuclei 
adhering to the sides of the fibre. A nerve-fibre termination, t, occurs in 
this field. Also a nerve-cell, which is only prolonged at one end into a 
nerve-fibre, c'. 
Fig. 15. The nerve-fibre now comes into relation with a large number of other 
fibres ; it then takes a sharp bend, nearly at right angles, and very 
shortly after can be traced to its termination in a bifid extremity. 
This is represented in fig. 16. 
Fig. 17. Meridional section through the margin of the umbrella of Aurelia aurita, the 
section passing through the middle of a lithocyst (semi- diagrammatic). 
b, Basal ; i, intermediate ; and t, terminal portion of the lithocyst. 
c. Cushion covering the lithocyst. 
ect. Ectodermic covering of lithocyst. 
ect'. Ectodermic covering of under surface of umbrella with the cut ends 
of the muscular fibres, mf 
ect" . Ectodermic covering of upper surface of umbrella. 
f.n.i. Fovea nervosa inferior. 
f.n.s. Fovea nervosa superior. 
m. Jelly-like mesoderm ; m, layer of mesoderm between ectoderm and 
entoderm of lithocyst. 
n. c . Nutritive canal passing to the interior of the lithocyst and 
continuous at its extremity through the stalk n, with the clump 
of the otolithic cells, o.c. None of my sections show a communi- 
cation of this canal with the exterior, as commonly described (see 
Huxley’s ‘ Invertebrates/ p. 135). 
p. Pigmented patch on upper surface of intermediate portion. 
Fig. 18. Vertical section (tangential to the margin of the umbrella) through the base 
of the lithocyst and the fovea nervosa superior. Letters as in previous 
figure. The fibrous stratum under the ectoderm of the fovea nervosa 
superior is seen to be in continuity with that under the entoderm of 
the nutritive canal. In the engraving of the figures this fibrous stratum 
has been imperfectly rendered, and in some places has been altogether 
omitted. 
