418 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
ends of the lateral lobes. ‘The right visceral connective 
comes in rather at an angle, the left beimg nearer the 
median line. 
Lying almost above the right connective, a little 
before it reaches the ganglion, and on the other side, a 
little to the left of the connective, are small pigmented 
bodies (G. osp.), which sections show to be ganglia made 
up of a cortex of ganglion cells with long processes passing 
into the centre, and with the outer ends drawn out into 
several fine fibres. From these osphradial ganglia, nerves 
pass up through the connective tissue to the epithelium 
directly above. Here they become connected with 
numerous sense cells, forming the Osphradium. 
The nerves connecting these osphradial ganglia with 
the visceral, pass into the cerebro-visceral connectives and 
enter the ganglion with these nerves. 
‘'wo conspicuous nerves arise from the visceral 
ganglion close to the entrance of the cerebro-visceral 
connectives, but slightly posterior to these. They arise, 
also, at a slightly higher level than most of the nerves 
which pass to the mantle. ‘These are the branchial nerves 
(fig. 28, V. br.); they pass out almost at right angles to 
the cerebro-visceral connectives, and just passing below 
the extremity of the renal organs, take up a position along 
the outer margins of the latter, where they are easily seen, 
being rather near the surface. This course 1s followed 
until the expanded end of the afferent branchial vessel is 
reached, when the nerves bend round and enter the 
ctenidial axis, along which they pass, gradually becoming 
more attenuated until the end of the lamellae is reached. 
The nerve les alongside and above the afferent branchial 
vessel along its whole length (fig. 45, 1. br.), sometimes 
nearer one side of the ctenidial axis than the other. 
This nerve is well supplied with ganglion cells, which 
