XX! GENERAL STRUCTURE 503 
The common Pyenogonum is, by reason of the suppression of 
certain limbs, rather an outlying member than a typical repre- 
sentative of the Order, whose common characters are more 
strikingly and more perfectly shown in species, for instance, of 
Nymphon. Of this multiform genus we have many British 
species, some of the smaller being common below tide-marks, 
creeping among weeds 
or clinging like Cap- 
rellae with skeleton 
limbs to the branches 
of Zoophytes, where 
their slender forms are 
not easily seen. In 
contrast to the stouter 
body and limbs of 
Pycnogonum, the whole : 
fabric of  Nymphon a A ey 
tends to elongation ; 4 Wy 
the body is drawn out Oat 
so that the successive ¢ ibe 
lateral processes stand ee NOS 
far apart, and a slender a A 
neck intervenes — be- 
tween the oculiferous // [| 
tubercle and the pro- "= ss 
boscis; the legs are 
produced to an amazing 
length and an extreme i ; 
degree of attenuation : i 
“mirum tam parvum — 
corpus regere tam ——v 
magnos pedes,” Says Fic. 263.—Dorsal view of Nymphon brevirostre, 
Hodge, x 6. Britain. 
Linnaeus. Above the 4 
base of the proboscis are a pair of three-jointed appendages, 
the two terminal joints of which compose a forcipate claw ; 
below and behind these come a pair of delicate, palp-like 
brevissimis compositi, ungue valido terminati. Ex descriptione patet insectum 
hoe a generibus antea notis omnino differre, ideoque novum genus, quod e crebris 
articulationibus Pyenogonum dico, constituit.”” The confusion between Cyamus 
and Pycnogonwm seems to have arisen with Job Baster, 1765 ; cf. Stebbing, A7iow- 
ledge, February 1902, and Challenger Reports, ‘* Amphipods,” 1888, pp. 28, 30, etc. 
