ISOPODA. 37 
these plumose set, but here they vary in length, and on both lobes the plumose 
structure exists only at the base, distally they become finely toothed. 
The maxilliped does not exhibit any special features. The basal joint is short 
with the outer angles, particularly the anterior one, rounded. The masticatory lobe is 
long, two-jointed, the inner margin straight throughout, but the outer margin of the 
distal joint rounded. The distal margin is occupied by numerous short plumose spines. 
The palp is five-jointed, the proportionate length of the various joints being about 
3. 3°5. 6. 5. 2. The entire organ is richly clothed with long sete, more especially 
internally and distally. With a one-inch objective these are seen to bear a number of 
fine setee about the middle of their length. The epignath is carried on a small plate, 
roughly ovate in shape, but having a flattened edge anteriorly. The epignath itself 
is a large plate ovoid though flattened on one side; it is just about as long as the 
masticatory lobe. 
The whole of these mouth organs are richly pigmented with black arborescent 
chromatophores. 
The first appendage of the mesosome is quite normal in general appearance, 
provided with long setee on its ventral side from the distal extremity of the basis; the 
merus has both dorsal and ventral margins rounded, the former projecting forwards as 
a blunt point with a small tuft of set; the distal extremity of the carpus projects in 
a similar manner ventrally. The propodus is by far the largest joint, though not so 
broad as the merus; the dactylus, including the terminal claw, is about two-thirds the 
length ; the claw has a very stout auxiliary. On the inner face of the propodus long 
sete are arranged in eight or nine series ; these and a very large proportion of those 
on or near the ventral margin are very finely toothed. 
The three following appendages are provided throughout their length from the 
distal extremity of the basis with groups of very long and shorter simple sete. The 
outer side of the basis carries a series of some half-dozen spines, and the ischium and 
merus have a dorsal and distal spine. 
The three posterior pairs of appendages of the mesosome are strong, the 
proportions of the joints of the middle one are 5°5. 3°25. 2.1°8. 5. 4. The basis 
bears several irregular but stout spinous processes along its dorsal border, the ventral 
border of the remaining joints, except the dactylus, are fringed with spines, these only 
develop as such along the ischium, dorsally there are a few scattered sete of variable 
length. The dactylus has a few small setee dorsally, but is otherwise smooth. 
Five specimens of this species were taken in 300 fathoms off the Ice Barrier, 
Bottom Mud, lat. 78. 25. 40. S., long. 185. 39. 06. E. Four of these are females, one 
scarcely adult, two with ova, and one with numerous young not yet emerged from the 
brood pouch. In these young the various segments are rendered conspicuous by 
transverse ridges, but the only spinous armature visible on the entire body are the two 
posterior horns of the urosome ; the cephalic horns are not present. 
