120 Mr. C. Spence Bate on Crustacea. 
as lateral dorsal spines, and tipped with a few spines and 
airs. 
We have taken ‘several specimens of Nika; and from their 
general resemblance to N. Couchi?, while possessing the chan- 
nelled telson of N. edulis, so particularly pointed out by Bell 
as specifically distinctive, I am much inclined to believe that 
there is but a single British species yet known, and that 
N. Couchit is but a variety of N. edulis, Risso. An examina- 
tion of its parts in detail has shown us that the mandibula 
(Pl. XI. fig. 3) are formed on a plan that nearer associates 
the genus with Crangon than with Alpheus, in the family 
of which (Alpheidee), the latter being the type, Nika is placed 
by Milne-Edwards and Bell, while Dana, more correctly we 
think, has placed it in a subfamily of the Crangonide, the 
Lysmatine. 
Two or three specimens of Athanas nitescens have been 
taken off Polperro. 
Hippolyte Barleet, which was described by me from a Shet- 
land specimen several years ago, must, I think, be expunged 
from the list of species, since, as pointed out by the Rev. A.M. 
Norman some time since, it is only an accidental variety of 
H, Cranchii. Observations of the Stomapoda on the south- 
western coast have been limited to a few of the commoner 
species : whether this arises from the species not being abun- 
dant on our southern shores as compared with those on the 
northern, or from accidental causes attributable to collecting 
arrangements, is yet to be determined. 
Amongst the smaller Crustacea, there is little to which I 
should wish to draw special attention, except the recent dis- 
covery of what may prove to be an undescribed Anthura, and 
some observations on the structure of Tanais. 
In 1861 Van Beneden asserted that the proper place of the 
genus Tanais was near to that of the family of the Diastylide, 
because the cephalon was developed upon the type of the cara- 
pace of the Decapoda. In 1864 this opinion was followed by 
Dr, Fritz Miiller, who stated that though he had been unable 
to identify branchial appendages, yet he felt assured that it 
possessed rudimentary organs, because he had observed a cur- 
rent of water playing from beneath the carapace. Recently, 
having obtained some living specimens, I have been able to 
support Dr. Fritz Miiller’s conclusion relative to the current of 
water; for, by the assistance of transmitted light, I have been 
able, through the walls of the carapace, to see the branchial 
appendage waving to and fro; since which I have dissected 
out the organ, a drawing of which accompanies this memoir. 
(Pl. XL. fig. 5.) 
