CYMODOCEA EMARGINATA. 429 
the flagellum of the upper pair (represented without the 
two basal joints in the middle right-hand figure), are fur- 
nished with flattened hairs at the tips. The foot-jaws 
have the three middle joints produced into long lobes, 
strongly ciliated at the tips, a portion of the cilia of the 
penultimate joint being set on at an obtuse angle to the 
rest. The basal portion of the tail has the middle of the 
hind margin extended backwards and emarginate, with 
a more or less distinct tubercle on each angle of the 
emargination. The middle of the upper surface of the 
terminal joint has two larger tubercles, followed by a 
depressed space, terminating generally in an erect tooth 
or obtuse point, the extremity of the joint armed with 
three obtuse points. The lateral appendages are very 
rugose and ciliated, the outer division nearly oval, but 
produced on the outside, at the tip, into a point; the 
inner division is narrower and curved, with the tip 
pointed. 
Dr. Leach took this species at Plymouth, under Mount 
Edgecombe. Mr. John Cranch found specimens, less 
strongly granulose, at Falmouth. We have received it 
from near Glasgow, taken by Mr. Robertson. The late 
Mr. W. Thompson found a specimen within the shell of 
a Balanus, affixed upon a Modiola vulgaris, from Belfast 
Bay. 
