ISOPODA. 37 



these plumose setae, but here they vary in length, and on both lol)es 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 plumo.se spines. 

 The palp i.s five-jointed, the proportionate length (jf the various joints being al)out 

 3. 3 "5. 6. 5. 2. The entire organ is riclily clothed with long setfe, more e.'specially 

 internally and distally. With a one-inch objective these are seen to bear a numl)er of 

 fine setss 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 meso.some is quite normal in general appearance, 

 provided with long setae 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 .setae ; the di.stal 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 

 setae 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 tliroughout their length from the 

 distal extremity of the Itasis with groups of very long and shorter simple setae. The 

 outer side of the ba.sis carries a series of some halt-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 mi(hlle one are 55. 325. 2. r8. 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, donsally there are a few .scattered setae of variable 

 length. The dactyhis has a few small .setae dor.sally, liut is otherwi.se smooth. 



Five .specimen.s 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 poucli. 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 tlic urosome ; the cephalic horns arc not present. 



