1 8 . T. Smith — Crustaceans of the Atlantic Coast. 
75 
often have both pairs of supraorbital spines well-developed, so that 
the two characters do not even accompany each other. This variety 
is evidently the form of which Miers (Annals and Magazine Nat. 
Hist., iv, xx, p. 62 (12), 1877) had a single specimen from Cape 
Frazer, Grinnell Land, and to which he refers under H. Phippsiif 
The following table exhibits these variations in a series of speci- 
mens selected from a much larger number. In the last column I 
have attempted to indicate the variation in the supraorbital spines, 
although it is impossible to express in words the completeness of the 
gradation between those individuals in which the lower spine is fully 
developed and those in which it is entirely wanting. 
Locality. 
Sex. 
Length. 
Grand Menan, 
S 
24’5mm 
it 
tl 
24-3 
it 
It 
25-0 
tt 
tt 
25-5 
It 
It 
25-2 
tt 
“ 
24-3 
“ 
“ 
21-8 
Cashe’s Ledge, 
It 
19 2 
it 
it 
170 
It 
It 
15-5 
“ 
“ 
18-5 
it 
tl 
17-5 
“ 
“ 
17-1 
It 
“ 
170 
tt 
it 
160 
“ 
16-5 
Isles of Shoals, 
« 
16-7 
Casho’s Ledge, 
tt 
16-6 
«• 
tt 
15-5 
Rostrum. 
Supraorbital spines each side. 
3 + 6 
4 
Two well-developed. 
4 + 5 
tl It 
3 
4 + 6 
2 
Two. one very minute. 
4 + 5 
3 
One only. 
4 + 5 
2 
One, with rudiment of 2d. 
4 + 6 
4 
One only. 
3 + 7 
tt It 
3 
2 + 6 
2 
Two well-developed. 
0 + 6 
2 
Two, one very small. 
3 + 5 
tt tt tl 
2 
3 + 6 
o 
[ble. 
Two, one scarcely percepti- 
3 + 5 
4 
4 + 6 
One only. 
it It 
4 
3 + 6 
3 
Two. 
4 + 6 
2 
One. 
3 + 7 
it 
3 
3 + 6 
4 
[ble. 
Two, one scarcely percepti- 
3 + 7 
3 
Ono. 
3 + 5 
9 
Two well-developed. 
