318 ASAJIRO OKA AND ARTHUR WILLEY. 
an outgrowth of the parietal wall of the abdomen. We can 
see indications of this curious process in our preparations, 
more especially plainly the buds from the cesophageal region, 
but we have not been able to trace the further development of 
them. 
The branchial tentacles of the Ascidiozooids are alternately 
long and short. 
4. Larve. 
The embryos having separated from the parent Ascidio- 
zooid sink into the deeper parts of the test, and there develop 
into large tailed larve. This is also very characteristic for the 
Didemnide. 
We wish to draw particular attention to the ring of twelve 
tentacle-like processes which surround the anterior end of the 
body of the larva, from which project the three adhering discs, 
These processes are hollow and communicate with the body- 
cavity, and contain very numerous blood-corpuscles. 
They seem to be of very general occurrence in the tadpoles 
of the Didemnide. Ganin (2) called them “ pelottenfor- 
migen Anhange,” and states that among six species of Di- 
demnum examined by him the number of these processes varied 
from four to fifteen or sixteen. Guard says (3, p. 610) that 
the Didemnidez “ ont des embryons pourvus de tubes stolo- 
niaux généralement au nombre de 8, trés-développés et préts 
i former des blastozoites quand le jeune oozoite sera fixé.” 
In different places of his work Giard calls these processes 
indifferently ‘‘ tubes stoloniaux,” “ tubes embryonnaires,”’ and 
‘tubes gemmiféres.” He figures them in the case of Lepto- 
clinum gelatinosum. Asa matter of fact, however, they 
have nothing to do with the budding, and Della Valle (loc. 
cit., p. 49) has rightly insisted that in the Didemnide the 
process of gemmation only commences after the larva has 
fixed itself. In spite of this von Drasche states wrongly that 
the embryos of the Didemnidz show “rudimentiare Knospung.” 
Herdman (7) has figured these processes in two species of 
Leptoclinum and in one species of Didemnum, but makes 
