252 LIVERPOOL BIOLOGICAL SOCIETY. 
numerous closely-placed tentacles. In Ciona intestinalis, 
the next commonest species, Copepoda are abundant in 
the branchial sac. There is a great deal of opaque white 
pigmentation in the mantle and branchial sacs of many of 
the specimens from round Puffin Island, and most of them 
have the stomach and intestine distended with fine mud, 
while the tentacles and vessels of the branchial sac are 
coated with the same, showing the muddy condition of the 
water in which the animals live. 
The dorsal tubercle is very variable in this species; one 
specimen from Puffin Island has it of elliptical form, the 
horns having united anteriorly. 
Ascidiella scabra, O. F. Muller. 
This is a species which I regard with a certain amount 
of doubt. Some specimens found on the shore at Puffin 
Island may either belong here or to the last species. 
Two small specimens of Ascidiella obtained at Groudle 
Bay, Isle of Man, by Mr. Clubb, most probably belong 
here. Their dorsal tubercles are very like those of Ascidia 
plebeia, but there are no papille in the branchial sacs, and 
their nerve ganglions are placed far forward, close to the 
dorsal tubercle. The branchial sac contained a parasitic 
Copepod, Doropygus pulex. 
A specimen found by Mr. Henry Thomas in the plunge 
bath at Llandudno Hydropathic, along with a number of 
specimens of Crona intestinalis, appears to be referable to 
the present species. It is an abnormal specimen, as it has 
two atrial apertures placed side by side on distinct atrial 
siphons. They are almost of the same size, and are each 
six-lobed. This is an interesting case of the persistence 
of an early post-larval character. 
Ascidiella aspersa, O. F. Muller. 
- A few specimens of this species were dredged off the 

