ISO POI) A. 
43 
joint approximately cylindrical and having a slight constriction near the proximal 
end, ventrally it bears a distal fringe of long setse ; 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 setse 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 setse distally, ventrally it is 
swollen but not to any great extent and thickly fringed with long setse, 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 band of setse of intermediate 
size. The dactylus 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 setse. 
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 II. 7. 4. 4. 7. 5. The basis and the two following joints 
are covered with small tubercles and have a few straggling setse, 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 setse. 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 antennse 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. 
Aattarcturus 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 
