
TUNICATA OF THE L.M.B.C. DISTRICT. Q49 
several specimens were obtained during the “ Hyzena”’ 
expedition of 1886. 
One of the specimens dredged off the Calf of Man 
resembles Asczdia depressa in external form, being flattened 
and elongated and attached by the whole length to a shell. 
Some of these specimens are of a rich brown colour, not 
only on the outside, but also in the mantle, branchial sac 
and viscera. 
The nerve ganglion in this species is placed far behind 
the dorsal tubercle, consequently this species may be 
referred to the genus Ascidia in the limited sense employed 
by Roule, and which will be referred to below. The 
tentacles are in nearly all specimens placed distinctly 
in two rows, the smaller ones being inserted on a line 
anterior to the rest. There are seventy-two tentacles in 
all, eighteen large, eighteen medium sized, and thirty-six 
small. 
In one of the specimens from the Isle of Man there is 
no dorsal tubercle in the large triangular peritubercular 
area, but there are a number of small rounded secondary 
apertures of the duct from the subneural gland into the 
peribranchial cavity. 
The specimens from near the Calf of Man contained in 
their branchial sacs some Copepoda which Mr. Isaac C. 
Thompson has identified as Doropygus poricauda, D. pulex, 
and Botachus cylindratus. The latter was present in 
large numbers both in the branchial sac and in the peri- 
branchial cavity, and adhered firmly to the walls by its 
hooked appendages. 
Ascidiella venosa, O. F. Muller. 
This species, the Ascidia venosa, or Phallusia venosa of 
most authors, is an addition to our fauna. ‘'wo large 
specimens and a small one were dredged from the ‘‘ Hyzena”’ 
