TUNICATA. - 497 
suddenly dilates as it approaches the body, which floats nearly at a 
right angle with it; and this portion, together with the whole sac, is 
strongly marked by deep, longitudinal wrinkles. The apertures are 
remote, shaped like the ace of clubs, on the summit of a prominent 
mammilla near each extremity; internally they are deep lake-red. Ex- 
ternal colour dirty ochre, deepest in the furrows. The tunic is very 
thick and rigid, with a slight cretaceous feel to the knife, and covered 
with a short, stiff pubescence, much resembling hatter’s fe/t. It is 
but slightly contractile, though the orifices may be so contracted as to 
disappear entirely. 
Length of the sac two and a half inches; diameter just above pe- 
duncle one and a half inches. 
Dredged in sixteen fathoms, Orange Harbour. [3. p. c.] 
Figures 612, 612 a, two views of the animal. 

In addition to the above are several carefully-drawn figures of the 
aggregated Tunicata, with brief notes by Mr. Dana. Among them 
are specimens of Botryllus, Polyclinum, Euccelium, and some curious 
forms, which are not yet given in zoological works, so far as can be 
ascertained. Asit is impossible to describe such animals from figures 
alone, with any tolerable degree of accuracy, the few notes respecting 
them will be reserved, and added to the explanations of the figures 
in the Atlas. Every carefully-delineated figure of these obscure forms 
will be valuable. in the attempts at systematic arrangement which 
must hereafter be made. 
125 
