BRITISH STALK-EYED CRUSTACEA. 303 
in the month of December, and from the fact of their being 
without ova at that time we may conclude that this species is 
probably with ova at the same period as those of allied genera. 
The localities known to us for this species are the Channel 
Islands, Plymouth, the Sussex coast, and South Devon; specimens 
are recorded from Galway, but we have little doubt, if carefully 
looked for, it will be found elsewhere. Prof. Milne-Edwards when 
he wrote his work, gave Falmouth Bay as the only known locality. 
Genus Inacuus, Fabr. 
We now come to a most interesting and characteristic little 
group, consisting of three species at present known to Britain, 
so similar in their general features as to form a distinct and 
decided genus, and yet so varied in their specific features as to 
enable the most casual observer to define and recognise each 
individual species at a glance. This genus, like the former two, is 
included in the popular designation of ‘‘ Spiders,” and the general 
form of the carapace supports the theory that it constitutes a link 
in the development to the triangular form of the genus Steno- 
rhynchus from the rounded or oval form of less highly developed 
genera and species. 
The general form of the carapace in this genus is that of a 
rounded triangle, spinous and developed into rounded promi- 
nences, which will be specifically described. The antenne are 
very short and the rostrum is stunted and cleft. The legs are 
long, but, like the peculiarity already mentioned with regard to 
the carapace, they appear to be in process of changing from the 
shorter and more easily protected appendages of the genera Pisa 
and Hyas to the long and attenuated legs of the genus Steno- 
rhynchus; they are also stout to the second joint, when they 
rapidly taper off to the terminal joint. 
The second pair of legs are the longest in both sexes. The 
abdominal segments are six-jointed in both sexes. The eyes are 
situated on short peduncles and are retractile, being the first genus 
we arrive at with this further peculiarity. 
Inachus dorsettensis, Penn. 
Bell says that this species was first described by Pennant from 
specimens in the Portland cabinet, and captured at Weymouth, 
giving it the name E-dorscttensis. M. Milne-Edwards has described 
it under the name of J. scorpio. 
