60 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
Stegosoma pellucidum, there is a well marked inferior lip, 
which projects considerably, as Moss himself has figured 
it (l.c. fig. 4). 
(83) The rectum and anus are high up on the right side 
of the body. In most forms they are median and ventvral ; 
in Appendicularva alone the anus is slightly to the right 
of the mid-ventral line. 
(4) Neither endostyle nor heart is indicated in Moss’s 
figure, although on the same plate he shews these struc- 
tures in his figures of other Appendicularians. 
(5) The pharynx is described as possessing a ventral 
fold, provided on each side with a longitudinal series of 
transverse stigmata, largest in the middle and becoming 
eradually smaller towards each extremity. 
(6) No external branchial (atrial) apertures on the sides 
of the body are mentioned or figured (see Plate V. fig. 1). 
It will be noticed that several of the peculiarities given 
in the above list are not to be found in the original 
description, which is characteristically short. They are 
derived, however, from a careful and critical examination 
of Moss’s figure; and so exact are his representations of 
Fritullarta and Ovkoplewra on the same plate, that they 
furnish us with an ample guarantee as to the general 
accuracy of the figure which more especially concerns us. 
It is usual to regard Mossia as noteworthy merely 
because of the rows of pharyngeal stigmata which it is 
said to possess; but the peculiarities which have just been 
mentioned are alone sufficient to distinguish it greatly 
from all the species of normal short-bodied Appendicular- 
ians. The conformation and length of the tail, the shape 
of the mouth and the position of the rectum and anus are 
without parallel in those genera; as is also, I may add, 
the apparent absence of heart and endostyle. Now these 
