350 Mr. G. M. Thomson on a new Species of 



while in the young the spines and tubercles are almost 

 wanting, there being only a few scattered hairs on the body, 

 as in P. australts. 



Eyes rounded and prominent, much larger than in the 

 Australian species. First pair of antennae with peduncle of 

 three joints and a seven-jointed flagellura, the last joint 

 minute. Second pair of antennse and first pair of legs 

 resembling the same organs in P. australis. 



Last segment of abdomen ending in a long narrow telson, 

 which is completely coalesced with it and which is furnished 

 with a few spines on its upper surfaces and bears a small 

 tuft of spines and sette at its extremity. 



All the legs are more or less spinose. Sixth and seventh 

 pairs of legs long, reaching as far as or beyond the extremity 

 of the pleon. Uropoda large, reaching beyond the pleon, 

 margin spinose, rami unequal, as long as the peduncle and 

 very acute. 



Length of the largest male specimen a little over \ inch. 

 Colour of dried specimens light brown or greyish. 

 In general form this species approximates to P. australis, 

 and as the latter has been very fully described by my 

 friend Dr. Chilton, I will make my description conform with 

 his species. 



Seen from above the front margin of the head is evenly 

 concave, the ratlier prominent round eyes being very close to 

 the front and separated by about half the width of the head 

 from one another. These organs are relatively rather large 

 and have from fifty to seventy lenses. Below the eyes is a 

 groove running back nearly to the posterior margin of the 

 cephalic segment, and serving to separate off a distinct, nearly 

 rectangular, lateral lobe. The thoracic and abdominal 

 segments and their epimera on the whole resemble those of 

 the Australian species, only spines replace the setfe. In my 

 dried specimens a spinous ridge occurs close to the anterior 

 and posterior margin of each segment of the thorax. The 

 telson also is a very prominent feature, being quite as long as 

 the segment which bears it. In PI. XL fig. 1 the telson 

 appears to be separated from the last abdominal segment by 

 a very distinct articulation ; this, however, is due only to the 

 point of view, there being a slight prominence on each 

 side of it, which hides the base in lateral view. In fig. 6 

 the complete coalescence of the telson with the segment 

 wliich bears it is seen. 



The first pair of anteunai reach to about the middle of the 

 fourth joint of the peduncle of the second pair. The peduncle 

 consists of three joints, of which the second and third arc 



