PYCNOGONIDA. 53 



Adstrodecus glacials. 



(Plate VIII. , fig. 1.) 

 Specific characters : — 



Body stout, segmented, with lateral processes close together. 



Proboscis long, tapering and curved near the extremity. 



Ohelifori absent. 



Palps 6-jointed ; terminal joint articulated to one side of the penultimate. 



Ovigers 6-jointed ? 



Legs short, first coxk armed dorsally with two spurs. 



Abdomen long and slender. 



This is a diminutive species ; the entire animal does not cover a space 8 mm. 

 square. 



The trunk is stout and distinctly segmented ; the lateral processes are not widely 

 separated, but as they are rather short and tapering, the intervals at their distal 

 extremities are very pronounced. The first coxae, which are the largest, all bear 

 dorsally a pair of stout tubercular spines which are very prominent. Each of the four 

 segments of the trunk bears a stout tubercle of some elevation in the middle line, and 

 close to its posterior border. 



The Cephalon is scarcely expanded, and almost fills the interval between the first 

 pair of lateral processes and their first coxae. Anteriorly it bears a very long Ocular 

 tubercle which is directed obliquely forwards, flask-shaped and truncated at its extremity, 

 on the upper surface of which, in a compact group, are four very well-developed eyes. 



From the truncated end of the trunk the Abdomen projects horizontally ; it is rather 

 long and not separated by an articulation. On the ventral surface of the trunk a 

 slightly raised band passes transversely between the first three pairs of lateral processes, 

 with the last pair the band is interrupted in the middle line. 



The Proboscis is long and of a peculiar shape, not unlike the snout of a weevil 

 beetle. It is movably articulated to the body, and for about one-third of its length it 

 is not disproportionately slender, then it tapers rather rapidly to a long and very 

 slender structure, curved downwards near the tip. It is quite smooth and presents an 

 annular appearance which is less distinct proximally. 



The Ohelifori are quite absent. 



The Palps are six-jointed and arise above but well to the side of the proboscis 

 (fig. lb). The first joint is short and very stout, the second is long and extends 

 beyond the extremity of the ocular tubercle. The third is very short and its distal 

 limit indistinct. The fourth joint is rather more than half the length of the second. 

 The second joint bears the stumps of several spinous setae along its length ; on the 

 fourth joint a similar number of curved spinous setse occur, and these increase in size 

 to the distal extremity of the joint, which also bears a few finer setae and a small 

 distal fringe. The last two are quite small and rather densely clothed with small setae. 

 The last one is articulated to one side, and not at the end, of the penultimate, and 

 the setae occur mainly on the outer side. 



