E. B. Wilson — Pycnogonida of New England. 
21 
slightly curved spines, which are longest proximally ; dactylus about 
two-thirds the propodus ; auxiliary claws less than half the dactylus. 
The legs are sparsely hairy, the hairs often forming, as in N. 
longitarse , a semicircle on the outer extremities of the joints. Color, 
when living, light salmon-yellow, the legs often banded with reddish 
or light purple. Length 10‘5 millimeters; extent 90 millimeters. 
This species is, in most of its characters, extremely variable. 
Kroyer’s N. brevitcirse and N. mixtum are undoubtedly, I think, forms 
of N. grossipes. The former are young specimens, with a short, thick 
neck, very short tarsus, and abbreviated rostrum ; the latter are 
those having a long slender neck, and with the tarsus from one and a 
half to two times the propodus. From the large collection in the 
Peabody Museum I have formed an almost complete series from 
extreme forms of N. brevitcirse to undoubted N. mixtum , though in 
none of the specimens of the latter species is the tarsus quite so long 
as that figured in the Voy. en Scand., Laponie, etc. The palpi, also, 
vary considerably with age. 
The variation is due in part to age, but is not sexual, since female 
specimens with egg-masses present the same differences. In some 
specimens the anteunai are tipped with brown, or jet black ; in others 
they are white. The terminal joints of the legs are sometimes simi- 
larly tipped with brown. 
The following table gives the relative length of the tarsus and 
propodus in a series of specimens selected to show the variation. The 
joints measured are, in all but one or two cases, from the second leg 
of the right side. 
Propodus. 
rum. 
Tarsus. 
ram. 
Ratio of 
t. to p. 
a (N. brevitarse.) 
0-465 
0-249 
0-54 
b 
0-498 
0-332 
0-65 
c 
0 930 
0-670 
0-72 
d (N. grossipes.) 
1-094 
1094 
1-00 
e 
999 
1195 
1-20 
f 
1062 
1-328 
1-25 
<J 
1-295 
1-693 
1-315 
h (N. mixtum.) 
1-228 
1-892 
1-541 
In PI. VII, figs. 1 i to 1 l , the variation of the neck is shown. All 
the latter specimens are adult females. 
This is, perhaps, the commonest species of the group. It was 
dredged by J. F. Whiteaves on Orphan Rank, Gulf of St. Lawrence, 
in 1 873, and extends as far south as hong Island Sound (two young 
specimens, off Race Pt. Rock, 50 fathoms, rocks and shells, F. S. Kish 
