REPORT ON THE TONIC ATA. 
417 
transversely. The meshes are square or slightly elongated longitudinally, and contain 
four to six stigmata each. 
The Dorsal Tubercle is small and circular in outline. It lies in a nearly symmetrical 
peritubercular area. 
Locality. — Station 233a, May 19, 1875; lat. 34° 38' N., long. 135° 1' E. ; depth, 
50 fathoms ; bottom, sand. 
This species is closely allied to the common and widely distributed Ciona intestinalis. 
A single specimen was dredged off Kobe, Japan, from a depth of 50 fathoms, the same 
locality in which Ciona savignii was found (see Part I. p. 236). 
The body, as figured and described above, is evidently greatly contracted, especially 
at the anterior end (PI. XLIX. fig. 11). Probably when living and expanded in seawater 
it would attain twice its present length, and under these circumstances the points of 
attachment to the Annelid tubes, which are now nearer the anterior than the posterior 
end, would be probably about the junction of the middle and posterior thirds of the body. 
The anterior end when expanded would certainly be much narrower than at present, and 
probably would be represented merely by the narrow region lying between the apertures. 
The posterior extremity has probably changed little. The surface would, when the body 
became expanded, lose much of its irregularity. The anterior corrugations would cer- 
tainly disappear, but the characteristic roughness due to projections of the test would of 
course remain. This roughening of the surface distinguishes the test very clearly from that 
of Ciona intestinalis and of Ciona savignii, and reminds one of the appearance presented 
by Ascidia aspersa, 0. F. Muller. 
When the test is removed the body presents a most characteristic appearance (PL 
XLIX. fig. 12). The anterior end is narrow and bears the two apertures. The posterior 
is very wide, and is evenly rounded like the posterior end of the test. The whole body 
is thrown into a strong curve having the convexity dorsal, but this is no doubt j)artially 
due to the state of contraction of the specimen. The siphons are prominent and the 
branchial is twice as wide as the atrial. The apertures are distinctly lobed, and the red 
ocelh are conspicuous. The sphincters surrounding the siphons are strong, and are con- 
tinued posteriorly as a series of circular bands running round the anterior end of the body 
for a short distance below the siphons. Behind this point the circular muscles are feebly 
developed, and they are almost entirely absent on the middle of each side. Along the 
dorsal and ventral edges and round the posterior end of the body they are rather stronger 
and run irregularly. The longitudinal muscle bands are very powerful, and are ten in 
number, five on each side. They are more closely placed ventrally than dorsally, and 
they approach more nearly to the ventral edge than to the dorsal, the most dorsally 
placed band being placed near the middle of each side. These longitudinal bands make 
their appearance from underneath the anterior circular muscles, and run backwards, 
(5500L, CHAlrL. EXP. — PART XXXVIII. — 1886.) Pp 53 
