28 Annelida Chcetopoda 
in Autolytus hesperidiim ; very thin, and the dividing line 
above not well marked, but existing. 
Eyes small, circular, umber-brown, on the posterior 
part of the head, four iu number ; the anterior pair lateral, 
the posterior pair just within the anterior, very near the 
posterior margin of the head, smaller thau the anterior. 
Antennae : the median arises between the anterior eyes, 
and when turned backward, reaches to the 8tb segment ; the 
lateral arise just in front of the anterior eyes, and are from 
one-third to one-half as long as the median. 
Tentacular cirri : the superior about as long as the 
lateral antennae; inferior one-half as long. 
First dorsal cirrus, nearly as long as median antenna. 
Second dorsal cirrus, one-half as long as first. 
The antennae and tentacular cirri habitually coiled in a 
flat or a conical spiral. Antennae, all superior cirri, and 
anterior margin of palpi, with numerous short, stifi" hairs. 
Dorsal cirri, a little less than width of body in length. 
Anal cirri, two in number, a little longer than the longest 
dorsal cirri. The antennae and all the cirri are irregularly 
wrinkled, and have nearly the same diameter from end to 
end. 
The proboscis terminates in rounded fleshy lobes ; the 
oesophagus, in a circle of flattened triangular papillae. It 
extends to the 8th segment, doubling twice on itself just 
before entering the stomach. The stomach occupies fromi 
three to four segments. 
Feet large, fleshy, cylindrical, bilabiate, anterior lobe 
slightly longer than posterior ; incision between the lobes 
very shallow. They originate along the line of union of 
the lateral and ventral surfaces, and are directed downward. 
Setae arranged in a single series, and directed downward 
and backward ; on the anterior segments about twelve to 
each foot, decreasing in number backward, till on the last 
segments there are only three or four. Body very convex 
