REPORT ON THE TUNICATA. 297 



which forms the bottom in some places off Bay Fine, was 

 bound together, to form an irregularly rounded mass, to 

 which the colony adhered by the stolons. 



In size, the Ascidiozooids varied from a few millimetres 

 up to 2*5 cm. antero-posteriorly. 



Perophora listeria Wiegmann. 

 This interesting form was first found on the English 

 coast in 1834, by Lister,* and has since been minutely 

 examined by Giard t upon the coast of Brittany. Some 

 colonies of Perophora listeri were dredged during August, 

 1885, off Spanish Head, near Port St. Mary, from a depth of 

 twenty fathoms. They are attached to Algae and Zoophytes. 

 This species was dredged by McAndrew and Forbes on the 

 coast of Anglesea, in 1843, but, so far as I am aware, it has 

 not been found in the neighbourhood since. 



The branchial sac of this species possesses the peculiarity 

 of having papillae upon the transverse vessels, like those of 

 Tylobranchion speciosum, | I am inclined to regard these 

 papillae as being rudimentary connecting ducts corresponding 

 to those which bear the internal longitudinal bars in most of 

 the Simple Ascidians. 



Family. — Ascidiid^ . 

 Ciona intestinalisj Linn. 



Ascidia intestinalis, Forbes and Hanley, Brit. Moll., v. i,p. 31. 

 A few specimens of this widely distributed species were 

 dredged off Port St. Mary, and off Port Erin, Isle of Man, 

 from depths of ten to twenty fathoms. A single specimen 

 was found by some members of the L. M. B. C. attached to 

 the under surface of a stone at the north end of Hilbre 

 Island, near low water mark. The species had not been 



* Phil. Tram., 1834, part ii, p. 365. 



t Arch, de Zool. Exper., t. i, p. 615. 



X See " Challenger" Report, part ii, p. 157. 



