APPENDIX to THIRD REPORT on the COPEPODA 
of LIVERPOOL BAY (the L.M.B.C. DISTRICT). 
By Isaac C. THompson, F.L.S., F R.M.S. 
With Plate IX. 
[Read 10th May, 1889.] 
S1ncE the Third Report on the Copepoda of Liverpool Bay 
was published, a new and interesting species of Copepod 
was taken by the dredge in Port Erin Bay, Isle of Man, 
during the fifth cruise of the “‘Hyzna,”’ in April, 1889. 
Several specimens, all females, some having ovisacs, were 
found by both Mr. W. 8. McMillan and myself in washings 
of muddy sand dredged from five fathoms. Besides a large 
number of Amphipoda, a few other species of Copepoda 
were found, amongst which were a number of specimens of 
Ectinosoma spinipes, Brady, which in general appearance 
the new species much resembles. It differs, however, 
from the characters of the genus Ectinosoma in several 
important particulars, especially in the anterior and 
posterior antenne and in the form of the fifth foot. In 
these and other particulars it so nearly agrees with the 
general form and generic characters of Jonesiella, Brady, 
that I have placed it in this genus. After careful dissection, 
however, I am unable to make out any jointing whatever 
in the anterior antenne, except one joint near the apex, 
and the animal is too minute and fragile to allow of the 
use of potash or any other clarifying medium which might 
disclose further structure. Another point of difference is in 
the inner branch of the first pair of swimming feet, which 
in Jonesiella has only two joints, while all the specimens 
of this species we have dissected have three joints. But I 
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