222 LIFE BY THE SEASHORE. 



slender appendages used for carrying the eggs. This pretty 

 little creature rejoices in the dreadful name of Phoxichili- 

 dium femoratum, and is to be found not uncommonly under 

 stones or clambering over weeds between tide-marks. 



Other forms often occur in numbers on weeds cast ashore 

 by storms. These are species of Nyiftphon, white or pinkish 

 in colour, and not unlike the last in appearance, but with 

 even more slender filiform legs, three or four times as long 

 as the body. They differ from the preceding in having, in 

 both sexes, three appendages in front of the first pair of 

 legs. Beside the mouth, as in Phoxichilidium, are two 

 small chelate limbs, behind these two pairs of slender 

 appendages, the first with four or five joints, the second 

 with nine. The first two pairs of appendages are used in 

 connection with food catching; the third in the male, as 

 in other Pycnogonids, carries the eggs, while in the female 

 they are functionless. The remaining four pairs function 

 as organs of locomotion in both sexes. This is the typical 

 condition of the appendages, from which the common 

 Pyenogonum littorale diverges widely. 



It is hardly necessary for us here to consider in detail the 

 special characters of these curious creatures, but we may 

 just note that their interest lies in great part in the fact 

 that their systematic position is very uncertain. The body 

 and limbs are segmented; they are undoubted Arthropods, 

 but the body is divided into three regions unsegmented 

 proboscis, trunk of four segments, and unsegmented abdomen, 

 and there are no antenna? or gills ; a connection with the 

 Crustacea is therefore not obvious. Of terrestrial Arthro- 

 pods spiders seem to resemble them most in the absence of 

 antennae and the presence of four pairs of legs, but spiders 

 have two appendages only in front of the first walking leg, 

 and sea- spiders may, as we have seen, possess three. Their 

 position is thus wholly doubtful, and the question of their 

 relationships unsolved. 



One other point of interest is found in the fact that, as 

 in the sea-horse among fishes, it is the male and not the 

 female which carries about the unhatched eggs. In the 

 Crustacea it is of course the females alone which do this. 

 Insignificant as the sluggish sea-spiders may seem to be, 

 they are thus not without points of interest. Nor are they 



