362 MR. ALDER ON ADDITIONS TO THE MOLLUSCA 
In addition to the above, all obtained by dredging, two species 
of Tunicata have been met with, not previously included in our 
local list. One of these is undescribed. 
CynTHIA EcuInaATA, Linn. 
Ascidia echinata, Mill. Zool. Dan., t. 130, f. 1, Forbes 
and Hanley, Brit. Moll. v. 1, p. 35, t.C.f. 4. 
Three specimens of this pretty species were got from the 
fishing boats at Whitburn. 
MoL@ULA SIPHONATA, n.s. 
Body roundish or ovate, inflated, with prominent non- 
retractile tubes ; adhering to marine substances by its base. 
Outer tunic soft, smooth, yellowish brown, or nearly 
colourless ; closely and uniformly covered with a thin 
coating of sand, which adheres firmly to its surface. 
Inner tunic smooth, transparent, of a lilac colour, shewing 
the viscera through, particularly the ovaries, which form 
whitish crescent-shaped lines on each side. Branchial sac 
deeply folded, with about six plaits on each side, a little 
festooned. Apertures tubular, nearly terminal, set a little 
apart ; branchial tube about a quarter of an inch long and 
nearly as wide, without colour, having six points, with 
sometimes slight intermediate ones surrounding the aper- 
ture; tentacular fringe branched. Anal tube rather 
longer and narrower than the branchial one, with four 
points at the margin of the aperture. Length, including 
the tubes, 13 inches; breadth variable, but generally 
nearly equal to the length. 
Two or three specimens of this Ascidian were found on the 
fishing lines at Cullercoats in October last. It approaches nearest 
in form to the Ascidia tubularis of Miiller, but differs in size and 
the smoothness of the surface. It is readily distinguished from 
the Molgula arenosa of our Catalogue by its projecting tubes, less 
regular shape, and more even surface. 
