A NEW GENUS OF SYNASCIDIANS FROM JAPAN. 317 
This remarkable condition was first described and figured 
by Della Valle (5), and then insisted upon as being of classi- 
ficatory importauce by von Drasche (6). 
As we have before said, we have not had the testis of our 
new genus under observation, so that it must be left doubtful 
at present whether the male gonad of this genus departs in 
any way from the usual condition of things in the other 
members of the family of the Didemnide. 
The remaining important characters which the new genus 
possesses in common with the other Didemnidz are—(a) the 
simple branchial sac, possessing only four rows of small oval 
stigmata; (0) long muscular processes of the mantle, which 
penetrate deeply into the test, and which are regarded as 
retractor muscles by von Drasche, who calls them “ Ecto- 
dermfortsitze ;”! (c) the absence of an oviduct. The ova float 
about in the body-cavity along with the blood-corpuscles, and 
as they grow in size they push the body-wall of the Ascidio- 
zooid before them, and so give rise to a sac which gradually 
separates itself by constriction from the Ascidiozooid, and 
finally comes to lie freely in the test (fig. 4). This process 
has also been described by Della Valle (5, pp. 38, 39). 
Tangential sections reveal the fact that the branchial aper- 
tures have an hexagonal form, corresponding to what von 
Drasche calls ‘‘ Sechszihnig.” 
The budding of the Ascidiozooids takes place on the same 
plan as that called by Giard pyloric budding, and which has 
been well described by Della Valle (loc. cit., pp. 48—56). 
The detailed discussion of this process must, for reasons stated 
above, be left to a future occasion. By this method of bud- 
ding, two different buds arise from the parent individual, and 
ultimately fuse together to form a new individual. One bud 
arises as an outgrowth from the cesophagus, and the other as 
! The muscles in these processes are prolongations of the two strong 
dorsal muscles, which converge together at the base of the pharynx, and are 
then continued into the test as a single muscular band. A short hollow 
vascular ectodermic process can often be seen apparently springing from the 
body-cavity of the intestinal region of an Ascidiozooid. 
