400 
EDWIN S. GOODRICH. 
three tentacles or prostomial cirri project forwards (figs. 1, 2). 
The median tentacle is generally raised up slightly above the 
two lateral tentacles which diverge from it; these are usually 
carried with their tips quite near tlie ground. All the 
tentacles are movable and jointed, and provided with sensory 
hairs. On either side, just in front of the ventral mouth, is 
a club-shaped movable palp, projecting from the ventro- 
lateral surface of the prostomium. Sensoiy hairs are set on 
the palps, and their anterior surface is strongly ciliated 
(figs. 2, 3). Where the prostomium joins the first segment is 
a deep ciliated groove on each side, it is the sensory nuchal 
organ commonly found in Archiannelids and in the Poly- 
chaeta (figs. 1, 2.) 
Each of the nine trunk segments bears a pair of parapodia. 
The segments vary in length, becoming shorter at the hind 
end of the body ; the first is not quite as long as the second, 
which is the longest of all. No well-marked inter-segmental 
grooves are visible, but indistinct annuli, five or six in 
number in most segments, occur all along the trunk. 
The parapodia are blunt hollow outgrowths of the body 
wall, to some extent retractile and elongated dorso-ventrally. 
Except in the first segment, each is provided with a dorsal 
and a ventral bundle of chaetae, and except in the last 
segment with a slender cirrus between them (fig. 4). The 
parapodium of the first segment is smaller than the succeed- 
ing ones. It bears only a dorsal bundle of chaetae, but its 
cirrus is much longer and more like the prostomial tentacles, 
both in structure and function, than are those of the other 
segments (figs. 1, 9). They are generally carried pointing 
directly outwards or slightly forwards. The chaetae of the 
first parapodium also differ from those of the other segments, 
being fewer in number (from 4—6) and pointing almost 
directly backwards (figs. 1, 2). 
The cirri of the next seven segments are indistinctly jointed, 
and provided with sensory hairs ; but they diminish in length 
and in the number of joints towards the hind end. They are 
also less movable, being carried stiffly sloping backwards. 
