442 PEOF. W. L. HEEDMAN ON BEITTSH TUNICATA. 



The oesophagus is very slender, the stomach pyriform, and the 

 intestine large. Figures 6 and 7 show the curves of the alimentary 

 canal. 



The remaining species dealt with by Hancock in this paper 

 are as follows — they are, I believe, all good species : — ■ 



Corella larvceformis, Hnk. = C. larvesformis, Hnk. 



C. ovata, Hnk. = G. ovata, Hnk. 



3Iolgula simplex, A. & H. = M. simplex, A. & H. 



M. inconspicua, A. & H. = ? a Ctenicella. 



M. complanata, A. & H. = Ctenicella complanata (A. & H.). 



Mugyra glohosa, Hnk. = E. glohosa, Hnk. 



It will thus be seen that several of Alder and Hancock's 

 species of Ascidia are merely forms of Ascidia mentula, and it is 

 a question whether we can recognize them as named varieties. 



I have for some years thought it extremely probable that 

 Hancock's Ascidia riibicunda and A. ruhrotincta at least, and 

 possibly other species in addition, were merely varieties of the 

 well-known A. mentula, and in my " Eevised Classification of 

 the Tuuicata," * I placed these amongst other species in a list 

 of doubtful forms. Eoule f, I believe, was the first to actually 

 place rubicunda and ruhrotincta definitely as synonyms of 

 mentula ; and Grarstang J has lately supported the same conclu- 

 sion by the examination of some specimens from the Isle of 

 Wight, which agree with " rubicunda " in form and with "men- 

 tula " in colour. I am not prepared to accept Garstaug's 

 classification of the varieties of mentula. It seems to me (and 

 I am influenced chiefly by having found, at Tarbert, Loch Fyne, 

 specimens of all varieties of colour, from pale grey and browa 

 to a gorgeous red, living together near low-water mark and 

 mostly attached by an extensive area of the left side) that the 

 " erect " or " depressed " condition is of more importance than 

 the red or pale coloration; so I would be inclined to suppress 

 ^^ ruberrima," ^'ruhrotincta,'^ and '■' rava," but retain " ei^ecta'" 

 and '^ depressa^^ as varieties §. However, it must be remembered 



* Journ. Linn. Soc, Zool. vol. xiii. 

 t Ann. Mus. Marseilles, t. ii. Mem. i. 18S4. 

 J Journ. Mar. Biol. Assoc, n. s. vol. ii. p. 119. 

 § Grarstang, /. c. p. 138. 



