74 
S. I. Smith — Crustaceans of the Atlantic Coast. 
Ocean and Bering Straits (Stimpson). ? Sea of Ochotsk (Brandt) and 
the island of Jesso (Stimpson) — H. Ocliotensis. Spitzbergen (Kroyer). 
Coast of Norway ! (G. O. Sars). 
The examination of a large series of specimens shows conclusively 
that Kroyer’s II. turgida is only the full-grown female of his Phippsii , 
as suggested by Goes, and that Stimpson’s vibrans is a mere variety 
without any real claim to specific rank. Kroyer included young- 
females under his Phippsii, as he distinctly states he had both sexes 
of that species, and it is not strictly true, as Goes implies, that all 
the males fall under one of Kroyer’s species and all the females 
under the other, for the young males and young females are almost 
indistinguishable, except by the essential sexual characters, and agree 
with Kroyer’s description of Phippsii. As in many similar cases of 
great differences in the sexes, the relation of the two forms may be 
easily established, with sufficient specimens, by tracing the forms 
back in two series toward the young, where the secondary sexual 
characters disappear and the two forms are seen to be specifically 
identical. In the present case the smallest females in which the sex 
is easily distinguishable differ scarcely at all in the form of the ros- 
trum and in the other characters which Kroyer gives as character- 
istic of the two species. 
I have never seen males which could be regarded as agreeing well 
with the characters of turgida as given by Kroyer, and I cannot 
explain the statement of Buchholz (who retains both Kroyer’s species 
though regarding them as probably varieties of one species) that he 
had, from East Greenland, two males of II. turgida , 30 to 35 nim in 
length, without supposing some mistake in the determination of the 
sex of the specimens, — a supposition which I have no sufficient reason 
for hazarding. 
The only characters which Stimpson gives for distinguishing his 
H. vibrans, found in Massachusetts Bay, from the Phippsii of Kroyer 
are that it has “ but one spine over the eye,” and that there are 
“ only two or three teeth beneath the tip of the rostrum.” The 
lower of the two supraorbital spines each side is really very small 
when best developed ; it is not at all constant, there being a com- 
plete gradation between specimens in which it is well-developed and 
those in which it is entirely absent ; and it often varies considerably 
on the two sides of the same individual. The number of teeth on 
the inferior edge of the rostrum is of even less importance as a dis- 
tinguishing character, for three or four is the usual number in the 
typical Phippsii and specimens with oidy two beneath the rostrum 
