A NEW. GENUS OF SYNASCIDIANS FROM JAPAN. 313 
On a New Genus of Synascidians 
from Japan. 
By 
Asajiro Oka, 
Of the Imperial University, Tokio ; 
AND 
Arthur Willey, B.Sc.Lond. 
With Plates XVII and XVIII. 
Tue remarkable compound Ascidian which we! are about to 
describe was collected in quantity by one of us at Moroiso, a 
place which stands at the head of a small bay to the north of 
Misaki, some fifty miles south of Tokio. It was found in the 
mouths of July and August, hanging downwards from the lower 
surface of the shelving rocks between the tide-marks, and is 
therefore exposed at low water at certain times of the year. 
It was soon regarded as probably a new form, and such has 
since proved to be the case. 
As will be seen below, the new genus belongs to the family 
of the Didemnidz, and the name we propose for it is Sarco- 
didemnoides misakiense. It may be considered as stand- 
ing in a similar relation to the genus Didemnoides that Sarco- 
botrylloides does to Botrylloides. 
The following description will be found incomplete in one 
or two points, partly owing to the time of the year at which 
1 The study of this Ascidian colony was commenced by one of us at 
Misaki, continued by both of us in Freiburg-i.-Br., and concluded by the other 
of us at Plymouth and Naples. 
VOL. XXXIII, PART 1J].—NEW SER. x 
