ISOPODA. 43 



joint approximately cylindrical and having a slight constriction near the proximal 

 end, veutrally it bears a distal fringe of long setae ; the ischium is small and enlarged 

 distally from a slender base ; the merus is also short but very broad, almost circular 

 though irregular in outline ; the carpus is short, its ventral margin being nearly three 

 times as* great as the dorsal. These three joints are together about as long as the 

 basis, and are plentifully supplied with long setae on their ventral surfaces, and the 

 two proximal ones have a few dorsally. The propodus is very nearly as long as the 

 basis, its dorsal margin is straight with a few long setae distally, ventrally it is 

 swollen but not to any great extent and thickly fringed with long setae, and a few are 

 a little further back from the margin ; on one side these are long, on the other they 

 are short, and near the dorsal margin there is an irregular baud of setae of intermediate 

 size. The clactylus is stout, but near its termination it becomes rather abruptly 

 reduced in diameter and the claw is accompanied by a small accessory ; the dorsal 

 and external face of this joint is very richly supplied with long setae. 



The three following appendages of the mesosome are of the normal type and do 

 not present any special features, they increase, in size from the first to the third and 

 the* middle one, which may be taken as the type, has a length of 15 mm. compared to 

 a body length of 27 mm. 



The three posterior appendages of the mesosome are long. The proportions of the 

 joints of the second are as 11. 7. 4. 4. 7. 5. The basis and the two following joints 

 are covered with small tubercles and have a few straggling setae, the inner margin of 

 the carpus and propodus bears a row of slender spines, and at the end of the latter 

 joint is a rounded lateral flange which supports the dactylus. This bears a very small 

 accessory claw. 



The uropoda are minutely tuberculated and fringed with long setae. The 

 marsupium of the female is composed of three pairs of plates, connected with the 

 third to the fourth appendages of the mesosome. 



This species was found in Winter Quarters at a depth of 125 fathoms. Only three 

 adult specimens were taken ; one of these is a female much larger than the specimen 

 described. This specimen is abundantly overgrown with hydroids, polyzoa, worm tubes, 

 etc., chiefly on the antennas and anterior appendages ; among all this were massed 

 not less than sixty young. These are quite devoid of the spines so characteristic of 

 the adult, and only two instead of the three posterior pairs of thoracic appendages 

 are to be detected. 



ANTARCTURUS MERIDIONALIS. 



(Plate VI., fig. 2.) 

 Specific characters : 



* Body slender, second antenna nearly twice the length of the animal, not conspicuously setose. 



Cephalosome as well as body quite devoid of any spines except coarse epimeral tubercles on the 

 first four free thoracic segments. 



Urosome rounded posteriorly, with a median ridge ending in a spine a short distance from the 

 posterior margin. 



N 2 



