oa HABITS hes 
Loman describes Phowxichilidium as feeding greedily on 
Tubularia larynz, and especially on the gonophores. It grasps 
them with its claws, sucks them in bit by bit till the proboscis 
is filled as far as the sieve, whereupon that part of the proboscis 
squeezes and kneads the mass, letting only juices and fine particles 
pass through into the alimentary canal. The lateral caeca and 
the rectum are separated by sphincter muscles from the stomach ; 
the former are in turn filled with food and again emptied; the 
contents of the alimentary canal are in constant rolling move- 
ment, and the faeces -are eliminated by the action of a pair of 
levatores ani, in round pellets. 
The Pyenogons, or some of them, can swim by “ treading 
water,” and Pallene is said by Cole to swim especially well; they 
more often progress half by swimming, half by kicking on the 
bottom. They move promptly towards the light, unless they have 
Hydroids to cling to, and Cole points out that when they crawl 
with all their legs on the bottom they move forwards towards 
the light,’ but backwards when they swim in part or whole. 
The legs move mostly in a vertical plane, horizontal movements 
taking place chiefly between the first and second joints.  Zany- 
stylum is uncommonly sluggish and inert; it sinks to the 
bottom, draws its legs over its back and remains quiet, while 
Pallene, by vigorous kicks, remains suspended. 
The long legs of the Pycnogons are easily injured or lost, and 
easily repaired or regenerated. This observation, often repeated, 
is as old as Fabricius: “ Mutilatur etiam in libertate sua, red- 
integrandum tamen; vidi enim in quo pedes brevissimi juxta 
longiores enascentes, velut in asteriis cancris aliisque redinte- 
gratis.” In such cases of redintegration of a leg, the repro- 
ductive organ, the genital orifice, and the cement-gland are not 
restored until the next moult.” 
Systematic Position-—To bring this little group into closer 
accord with one or other of the greater groups of Arthropods is a 
problem seemingly simple but really full of difficulty. 
The larval Pyenogon, with its three pairs of appendages, 
resembles the Crustacean Nauplius in no single feature save 
1 Loeb (Arch. Entw. Mech. v. 2, 1897, p. 250) also says that the Pyenogons are 
positively heliotropic. 
2 See also P. Gaubert, ‘‘Autotomie chez les Pyenogonides,” Bull. Soc. Zool. Fr. 
XVii., 1892, p. 224. 
