RECORDS OF W.A. MUSEUM. 
ii8] 
The mouth is radial, situated at the base of the anterior arm 
pair. 
The arms are all of equal length and size, 85 mm. long, 
2-5 mm. wide at the base, and 4-3 mm. wide at the broadest place, 
between the twelfth and fourteenth brachials. 
The terminal comb on the proximal pinnules is composed of 
fifteen teeth which are long and slender, shaped like an arrow head 
with the point truncated. 
All the arms bear ungrooved pinnules in equal numbers. In 
the proximal portion of the arms the pinnules on either side typically 
alternate, grooved and ungrooved ; further out tliere are two 
grooved pinnules between adjacent ungrooved pinnules, and 
toward the arm tips all the pinnules are grooved. 
There is a very great difference in the structure of the grooved 
and ungrooved pinnules, which is well shown in the more proximal 
portion of the arm where the two types regularly alternate. The 
grooved pinnules, after the first two segments, which are rather 
large, are slender, delicate and very flexible ; the ungrooved 
pinnules have slightly larger basal segments than the grooved and 
taper very gradually so that they are much stouter than the 
delicate grooved pinnules ; at first they lie horizontally, but in the 
distal half or third they curve dorsally into the form of a hook or 
spiral, exactly as do the cirri, forming tendril-like attachments all 
along the arm whereby the animal fixes each arm securely to the 
organisms on the sea-floor in addition to fixing its central portion 
by means of its cirri. 
The segments of the stout grooveless pinnules are produced 
dorsally into blunt rounded processes exactly resembling the dorsal 
convex swellings on the outer cirrus segments ; these are perfectly 
smooth, with no trace of spines; these processes are entirely absent 
from the slender grooved pinnules w'hich, instead, bear on the 
dorsal side of the terminal segments the long recurved spines 
characteristic of the pinnules of all the species of this family. 
The colour in life was purplish red, the centrodorsal and first 
seven segments of the cirri darker and more brownish, the distal 
portion of the cirri bright red. 
Remarks. Morphologically the first two segments of the 
pinnules are merely atrophied brachials, while the remaining 
