ISOPODA. 



19 



notch, as indicating the presence of another joint. This distal portion is rounded, and 

 bears at its inner extremity three prominent teeth. At the notch above alluded to 

 there is a very small finger-like joint armed with two teeth. 



The maxilliped (fig. 3) is a very stout appendage. Its basal joint occupies rather 

 more than half the length of the entire structure, the distal joint is triangular and 

 slopes away from the inner margin of the appendage. In the palp five joints may be 

 distinguished ; the first is short and broad, the second is roughly triaugular, the base 

 being internal, the third is the largest and irregular in shape, being expanded 

 internally. The two terminals are small, and bear three or four strong teeth and a 

 few spinous setae. The epignath is about three-quarters the length of the basal joint, 

 forming a slightly rounded cone with a few setae distally. 



The first pereiopod (fig. 4) is short and stout ; the first joint or basis is very much 

 the largest joint, the ischium is short, expanded distally, and forms the bend of the 

 limb in its natural position ; the merus is short and broad, bearing on its inner margin 

 four stout stumpy spines ; the carpus is equally broad, but not half the length, and 

 bears two stout spines on its inner margin ; the propodus is a little longer than the 

 two preceding, with two strong spines and a few setae in connection with the distal 

 one. The dactylus is longer than the propodus, and forms a very strong curved claw ; 

 the inner margin of this for more than half its length bears a thin membranous 

 addition to its edge. 



In the two succeeding periopoda the merus projects over the base of the succeeding 

 joint both dorsally and ventrally, but especially the latter ; the carpus also projects 

 ventrally, in both cases forming a curved spinous structure. 



The remaining four pairs (fig. 5) are also much alike, but more distinctly destined 

 for locomotion than for prehension. Their proportions are not exactly the same. The 

 basis is the largest and strongest joint. The ischium and merus together are scarcely 

 as long ; the former is prolonged dorsally over the latter, and the latter also, but to a 

 much less extent. All the joints except the first have distal fringes of very strong 

 setae, and the ventral margin bears setae arranged more or less distinctly as short 

 transverse bands than in a single row. They are, however, arranged as a row on the 

 propodus. The terminal claw is of quite moderate size but powerful. 



The pleopoda ore of a tolerably uniform character. In the first the protopodite 

 is stout and very broad. The exopodite and endopodite are situated at subequal 

 intervals from the margins and each other. 



The exopodite is egg-shaped, the round end being free and thickly fringed with 

 long plumose setae ; the endopodite has a straight and thickened inner edge and is 

 more triangular in shape, the apex being rounded and fringed with plumose setae. 



Specimens of this species were taken occasionally throughout our stay in Winter 

 Quarters, at depths down to 125 fathoms. The smallest example is scarcely 12 mm. 

 long. Several more or less digested specimens were taken from the stomach of a 

 Weddell's seal. 



K 2 





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ss--.Cs 



