160 THE VOYAGE OF H.M.S. CHALLENGER. 



Fig. 5, Innervation of the rudimentary eyes of Nymiihon rohtistum, Bell ; magnified 94 

 diameters, n, optic nerves forming the ganglion g ; t, oculiferous tubercle ; 



0, rudimentary eyes. 



„ 6. Innervation of the proboscis of Nijmphon rohustum, Bell; magnified 10 dia- 

 meters. The proboscis has been figured as transparent ; the mandible and 

 the palp of the left side have been cut away, t, oculiferous tubercle ; s, supra- 

 cesophagal ganglion ; c, cesophagal commissures ; ti, azygous proboscideal 

 nerve ; ^, secondary proboscideal nerves arising from the supraoesophageal 

 ganglion ; mn, mandibular nerves ; 'p, proboscideal nerves arising from the 

 first thoracic ganglion ; g, ganglionic bundles ; x, small ganglia in the front 

 of the proboscis ; y, large proboscideal ganglia ; a, first proboscideal nerve 

 ring ; a'-ct'"^ second to fifth proboscideal ring. 



„ 7. Transverse section of cephalothoracic segment of Colossendeis leptorhynchtis, 

 Hoek (female specimen) ; magnified 10 diameters, s, supraoesophageal gan- 

 glion ; t, first thoracic ganglion ; os, oesophagus ; c, oesophageal commissures ; 

 i, rudimentary coeca of the intestine ; m, and m'. muscle-bundles ; m, passing 

 through the oesophageal commissures. 



„ 8. Part of the ganglionic bundle in the proboscis of Nymphon rohustum, Bell*; 



magnified 94 diameters, u, g, a, a', a", x, and y, as in fig. 6. 

 „ 9. Transverse section of the proboscis of Nymphon rohustum, Bell ; magnified 23 

 diameters. I., II., and III. the three chitinous plates limiting the oesophageal 

 cavity ; t, transverse muscles ; I, longitudinal muscle-bundles ; a, proboscideal 

 ring ; g, ganglion of the ganglionic bundle ; ^3, the three main proboscideal 

 nerves on transverse section. 



,, 10. One of the ganglia on the inner surface of the integument of Colossendeis i^ro- 

 boscidea, 8ah. (sj).) ; magnified 272 diameters, c, integumentary cavities; 

 b, blood-corpuscles. 



„ 11. Six sections through the supraoesophageal and first thoracic ganglia of Nym- 

 phon stromii, Kroyer ; magnified 56 diameters, s, supraoesophageal ganglion ; 

 ce, oesophagus ; t, first thoracic ganglion ; i, intestinal coecum for the 

 mandibles ; c, fibres of connective tissue ; o, optic lobes ; o', part of the 

 optic nerves ; m, mandibular lobes ; x, azygous lobe of unknown function ; 

 CO, oesophageal commissures ; p, origin of the two main proboscideal nerves ; 



1, origin of the nerves for the ovigerous legs ; co', commissures between the 

 first and second thoracic ganglia. 



,, 12. Longitudinal section through the first thoracic ganglia of Nymjyhon brachy- 

 rhynclms, Hoek ; magnified 170 diameters, pr, proboscideal nerves ; pa, part 

 of the neurilemma of the palpar nerve ; e, part of the neurilemma of the oviger- 

 ous nerve ; c, commissure between this and the second thoracic ganglion. 



