ISOPODA. 51 



stout, witli ,1 riiitteueil ventral odgo .iiiiicil with a couple of spines. The propodus 

 is stout, nearly as long as the daetylus, with a .somewhat Hatteiiecl edge vcntrally 

 and armed with a .spine. 'J'lie daetylus is rather stout at the hasc, tapering and 

 curved, with a spiue or a<ee.s.sory claw about the mitldle of its length veutrally. 

 The remaining pereiopoda are much more slender, subequal in size, and comparatively 

 small ; the distal joints are eylindrie^d, and there is a stout curved .seta on each 

 daetylus. 



Only a single specimen of this species was found among the dredge material 

 in Felnuary, 1902, before the ship was frozen in to Winter Quarters, inside the 

 20-fathom line. 



AU8TR0FILIUS. 



Cephalo.some three lobed, the median one forming a broad rostral plate, the 

 lateral ones flattened and bearing the small eyes. 



First antenna small. 



Second antenna, six-jointed peduncle, third joint with an external .spine. 



Mesosome having its segments variable, but not distinctly divided into two 

 divisions. 



Meta.some forms u single plate with small preterminal biramous uropoda arising 

 ventrally. 



Pereiopoda all ambulatory, of moderate length. 



AUSTROFILIUS FURCATUS. 



(Plate VIII., fig. 2.) 



The ceplialosome is not quite so broad as the first segment of the mesosome, 

 and over all it is about as long as the first two .segments. The anterior part is 

 reduced to nearly half the diameter of the posterior, and tapering slightly it 

 terminates in two stout but widely separated spines. The antennae arise in the 

 rounded depression on either side of this rostrum, if such it may be called. The eyes 

 are small and dorso-lateral in position, borne on small rounded tubercles. 



The form of the mesosome is not easy to describe ; brieHy, the six anterior 

 segments are .separated from one another by conspicuous bands of dermis softer than 

 that which makes up the bulk of the segment. The first three progressively increase 

 in width, though only slightly, the remainder decrease in a similar way. 



The first segment is the longest, and is slightly curved forwards and ot iniiform 

 length throughout. Referring only to the harder parts the .second is little more than 

 half the Icngtli in the miil-dor.sal line, but increases laterally to be .sul)C4UaI in length ; 

 the third is intermediate iu length, <iirved forwards laterally ; the fourth is straight. 

 The lateral margins of all these segments are more or less rounded and seto.sc. The 

 fifth segment is the shortest, widening laterally, and not setose ; the sixth and seventh 



o 2 



