28 13KITISH TUNICATA. 



naturalists, In the figure of A. rirt/iiira given in the 

 ' Zoologia Danica,' the intestine rises in a sigmoid 

 curve half way up the side of the sac as is usual in the 

 genus Aseidia ; but in the present species, and indeed 

 in all the three members of the genus Corella, the intes- 

 tine, after running along the base of the sac, ascends 

 in a direct line to the anal aperture, the stomach being- 

 placed 011 the left side. This is therefore a sinistral 

 species, and its two congeners are the only other 

 sinistral species which have occurred to us. The 

 Phallusia turcica of Savigny is also a sinistral species, 

 and has the same flexure of the intestine. 



GoreUa parallelogram ma is found 011 the Norwegian 

 coast, but does not extend northwards bevoiid Lofoten, 



/ 



where it is rare and of small size Sn 



2. Corella larvseformis Hancock. 

 (Plate XXII, fig. 8.) 



Corella larv&formis HANCOCK in Ann. Nat. Hist. [(4) VI 

 (1870), p. 363]. 



Body irregularly rounded or subquadrate, com- 

 pressed, adhering by the base. Apertures, branchial 

 terminal, only slightly prominent, atrial at the upper 

 part of the neural margin, a little removed from the 

 branchial, at the extremity of a tube which is con- 

 siderably longer than the entire body, and projects 

 diagonally upwards; ocelli red. Test firm, smooth, 

 shining, thin above, rather thick below, perfectly 

 crystalline, exhibiting not only the colours of the 

 mantle, but likewise much of the internal structure. 

 Mantle delicate, adhering to the test, of a yellowish or 

 reddish colour, with a few scattered, small red spots, 

 and so transparent that it does not in the least obscure 

 the view of the contained visceral organs. Branchial 

 sac with large, spiral coils, the largest about five times 

 coiled, in 12 or 1-4 transverse rows ; papillae replaced 

 by the thickened border of the papillary membrane. 



