166 Mr. J. Alder on the British Tunicata. 



British form, I do not hesitate to adopt his name. It appears 

 also to be the Cynthia gutta of Stimpson. The true Ascidia 

 ?iistica has not yet been met with in this country ; but I have 

 lately found, in the collection of the late Mr.Wm. Thompson, of 

 Belfast, a Cynthia from Killery Bay, on the west coast of Ireland, 

 which appears to be the second form figured by Miiller, and 

 which is probably also distinct from the C. rustica. It is nearly 

 spherical, with a thin delicately wrinkled test, and is about 

 three-quarters of an inch in diameter. 



Cynthia grossularia is an extremely variable species, changing 

 its appearance so much in different situations and under different 

 circumstances, that we have sometimes been induced to think 

 that more than one species might be included in it. When 

 growing singly, it is rather depressed, and the test spreads into 

 a thin membrane round the base ; but, in sheltered situations, 

 as under shelving rocks, the individuals accumulate in compact 

 masses, so closely packed as to allow of growth only upwards, 

 and adhering very firmly to each other at the sides. The young 

 in such cases often attach themselves to the surface of the 

 parent, so as, at first sight, to appear as if budding from it. In 

 the more free state, likewise, the spreading bases of several indi- 

 viduals sometimes come into contact and unite; but, on careful 

 inspection, the line of union can generally be detected. The 

 test, viewed as a transparent object under the microscope, always 

 shows transverse anastomosing corrugations ; but it often appears 

 smooth to the naked eye, especially in the young state. 



Cynthia glomerata, n. sp. 



Body ovate or subglobose, smooth, cherry-red, the individuals 

 crowded into closely adherent clusters. Apertures rather small, 

 not far apart, very slightly prominent, quadrate, but sometimes 

 appearing as a simple slit when closed. Test tough, rather 

 shining, smooth, or sometimes very slightly wrinkled in old in- 

 dividuals, closely adherent to the mantle. Mantle bright crim- 

 son. Tentacular filaments slender. Branchial sac red, with one 

 large fold, and a smaller one on the left side, and two or three 

 obscure ones on the right : the largest folds are near the ventral 

 plait, which is smooth. Ovaries disposed in small crimson pel- 

 lets over the inside of the mantle. Height from a quarter to 

 nearly half an inch. 



This interesting species was found cast up, after a storm, at 

 Wick, by Mr. C. W. Peach. It differs from most of its con- 

 geners in the smoothness of its test and the little prominence of 

 its apertures, which are generally level with the surface when 

 closed. The beautiful group from which the description is taken, 



