124 " ENDEAVOUR " SCIENTIFIC RESULTS. 



PlLUMNUS ACER, Sp. UOl'. 



(Plate xxix.) 



Type-locality. Sixty to eighty miles west from Eucla, 

 Great Australian Bight, 80^-120 fathoms; E.3178; one 

 male holotype, one ovigerous female. 



Additional localities. South-west of Eucla, about long. 

 127 E., .Great Australian Bight, 80-120 fathoms; E.3663; 

 one male. 



Sixty to eighty miles west of Eucla, 80-120 fathoms; 

 P. 3564 ; one male, one ovigerous female. 



Measurements. Male holotype, total length of carapace 

 15.4, width without spines, measured behind the last pair, 

 20.4 ; width with spines 22.3 mm. 



The gastric region and its three subdivisions are faintly 

 outlined; a little deeper groove runs from the mesogastric 

 region to the median sinus of the front. The dorsal surface 

 of the carapace and appendages is covered with numerous 

 hairs which are distinctly yellow in the specimens preserved 

 in alcohol, and of different lengths, but on the whole rather 

 long, and placed singly with few exceptions. The width of 

 the front is less than half the length of the carapace; its 

 large lobes are so denexed that they do not show in a 

 dorsal view, they are subtriangular, ends broadly rounded, 

 outer slope longer than inner, edge obscurely granulate, as 

 is also the upper margin of the orbit. This shows two 

 small, subequal, rounded sinuses, and at the outer angle a 

 slender spine. At the inner suborbital angle there is a 

 slender spine springing from a conical base ; on the lower 

 margin there are also six or seven small spines or spinules, 

 the outer of which is the largest and is separated by a 

 V-shaped sinus from the exorbital spine. Suborbital 

 region with one larger spine and one or two smaller spines 

 and some spinules. Further back on the lateral border 

 there are three slender horny spines set in larger, cylindrical 

 sockets, from each of which spring behind the spine two 

 or three hairs longer than the spine. 



The two spines near the distal end of the arm are similar 

 to those bordering the carapace, and are succeeded by a 

 few spinules; lower margin with a few small tubercles, 



