BRITISH STALK-EYED CRUSTACEA. 305 
We have not yet had an opportunity of seeing the zoee form, 
but imagine it to resemble that of the genus Stenorhynchus. Our 
excuse for referring so frequently to genera already described is, 
that we find points of definition and determination are much 
better understood by drawing comparisons to what is already 
recognised and familiar; besides the interest which attaches to 
the development of forms from one type to another under new or 
varied conditions of existence. 
Inachus dorhynchus, Leach. 
This species so much resembles the last that it will be more 
easily understood if we simply describe the specific distinctions. 
The carapace is less developed into rounded bosses, and the row 
of four small tubercles which characterises I. dorsettensis is repre- 
sented in this species on the anterior portion of the carapace by 
two spines, one situated beneath each spine of the orbit. 
The rostrum is nothing more than the anterior angle of the 
carapace cleft to a slight depth, varying in some cases to a mere 
notch. The hands are smoother than those of the former species, 
and the first two joints of the other legs less robust. 
Bell seems to think that its resemblance to the former species 
may cause it to be mistaken for that, and thus account for its 
apparent rarer occurrence. We are, however, inclined to think 
that it is undoubtedly far less common than J. dorsettensis. We 
have also observed a most decided difference in general appear- 
ance ; I. dorhynchus being smaller, less robust, and of a pinker 
colour than the species previously described. This species is 
also generally cleaner and brighter, and less affected by artificial 
covering of sponges, &c. The female was unknown to M. Milne- 
Edwards. 
Inachus dorhynchus has been recorded as taken at Shetland, 
Belfast, Dublin Bay (common), Galway, St. Andrews (occasionally), 
Cornwall, Hastings, Durham, and Berwick. We have obtained it 
from Jersey, from crab-pots, in November, when some of the 
females were with mature ova, which resembles that of J. dorset- 
tensis, but we have had little opportunity for examining it as yet. 
Inachus leptochirus, Leach. 
This most interesting species differs from the two preceding 
in one or two important details. The carapace is extremely like 
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