PYCNOGONIDA OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 177 



composed ventrally of stout spines. On the tarsus and propodus the setae are small 

 and inconspicuous ; there is a row ventrally along the two joints in which the setae are 

 more regular than elsewhere, but there is nothing very distinctive about them. 



The specimen described above is an adult female, and the genital apertures occur, 

 as usual, on all the legs. Those of the male occur only on the two posterior pairs of legs. 

 The male differs further in being more coarsely setose, though the arrangement of the 

 setae is identical. The fifth joint of the oviger is abruptly expanded to more than twice 

 its normal diameter, and the sixth joint is also expanded considerably, but is reduced to 

 something like normal diameter distally. The denticulate spines are a little more 

 numerous than in the female, being 11, 7, 6, 8. 



A number of specimens were taken in Scotia Bay, in less than 10 fathoms, during the 

 stay of the Scotia. 



Pentanymphon antarcticum. 



Pentanyrnphon antarcticum, Hodgson, (10), pp. 458-462; (11), p. 35; (13), pp. 36-39. 

 „ „ Cole, (6), p. 105 ; Bouvier, (3), p. 4. 



Only a single specimen, an adult female, was taken by the expedition, and was found 

 among a large number of Chsetonymphon orcadense from Scotia Bay, in 10 fathoms. 

 It is more robust than the average specimens from M'Murdo Sound ; the scabrous 

 nature of the body is more distinct, but this is not readily noticeable. Its neck, 

 though a little shorter in proportion to the type specimens, does not appear to be more 

 than an individual peculiarity. The joints of the legs have the same proportions as the 

 types, but the tarsus and propodus vary on the different limbs more than usual for a 

 single individual. The denticulate spines of the ovigers are much worn, and quite 

 useless for specific discrimination. The genital apertures occur on the second coxa of 

 all the legs. 



Scotia Bay, 10 fathoms. 



Ammothea communis (Plate II., figs. 1, la). 

 Ammothea communis, Bouvier, (3), p. 6. 



Specific Characters. — Body discoid, with lateral processes close together ; they and the 



first coxae armed dorsally with two stout spurs. 

 Palps eight- jointed, last three progressively increasing in length. 

 Oviger ten -jointed, small ; few denticulate spines, no claw. 

 Legs stout, uniformly setose ; terminal claw stout, with two well-developed auxiliaries. 



Four strong spines on propodus. 



Body discoid, the lateral processes being close together ; these are armed with two 

 stout spurs dorsally and distally, and similar but stouter ones occur on the first coxae. 

 Of these the posterior one is always the largest. 



