Mr. C. Spence Bate on two new Crustacea. 409 
series) ; none on the sixth. The first sixteen vertebre 
of the series are cervical ; and if the four missing verte- 
bre be added, it makes twenty cervical vertebre alto- 
gether. The last seven are dorsal. The neural spine 
becomes single on the nineteenth. The hypapophyses 
become single on the eighteenth ; and they are furthest 
apart on the fourteenth. I have taken the first of this 
series as the fifth; but, judging, from B and E, it may 
possibly be the sixth, in which case the rest of the neck- 
vertebree would agree with H. This specimen has also 
the pelvis and the caudal vertebree, of which latter there 
are ten, the last two being ankylosed. The second 
caudal vertebra agrees with the one figured by Prof. 
Owen as either the first or the second. 
From a comparison of these necks with the drawings and 
descriptions of Prof. Owen in his last paper I infer that the 
vertebra figured by him as the third is really the fourth, that 
figured as the fourth is the sixth, that as the sixth is the 
eighth, that as the twelfth is the fifteenth, that as the four- 
teenth is the seventeenth or eighteenth, and that as the 
fifteenth is the twentieth or twenty-first. 
XLVII.— Two new Crustacea from the Coast of Aberdeen. 
By C. Spence Bats, F.R.S. 
Two small Crustacea were sent to me some short time since 
by Mr. Sims, of Aberdeen, as having been taken by him on 
that coast during last summer. One belongs to the Diasty- 
lide, the other to Amphipoda. After carefully noting all the 
specimens with which I am acquainted, as well as consulting 
the works of Sars and other naturalists, I am induced to be- 
lieve that neither of them has been described. I propose 
therefore to name them respectively Diastylis bimarginatus 
and Lestrigonus spinidorsalis. 
Diastylis bimarginatus has the carapace very long and 
oval. ‘The infero-lateral margin is anteriorly serrated be- 
neath the antennal notch. A second ridge within the 
lateral margin repeats it, commencing at the base of the 
rostral process, where it is serrated, and continuing until 
near the posterior extremity of the carapace, where it 
becomes confluent with the infero-lateral margin. The rostral 
projections of the carapace are serrated on the upper mar- 
gin. Five somites of the pereion are exposed behind the 
carapace, each becoming longer, narrower, and less deep as 
