MUSEUM OF COMPARATIVE ZOÖLOGY. 41 
in connection with the species which I have used in common with them, 
or in the general part of this paper, in considering the process of budding 
in Bryozoa as a whole. 
I will begin my description with Bugula turrita* of Verrill, which I 
gathered in the summer of 1889 at Wood’s Holl, where it occurs abun- 
dantly on the piles of the wharf. The stock is bushy, and, when its 
polypides are active, of an orange color. In its simplest form the 
stock consists of a central axis, which is somewhat zigzag, and gives off 
lateral branches like the trunk of a tree. The lateral branches are in- 
serted on the trunk in a spiral line. Each lateral branch is fan-shaped 
(Plate VII. Fig. 64), the part corresponding to the handle of the fan 
being the point of attachment, and the fans are smaller the nearer they 
are to the tip of the trunk. The attachment of the branch to the 
trunk is effected by one primary individual. Each fan-shaped branch 
extends from its point of attachment obliquely upward and outward, 
and, although it is slightly concave on its upper inner surface, the 
concavity is not sufficient to prevent its being spread out upon the slide 
for study without materially disturbing the interrelation of the indi- 
viduals in the stock. 
I have studied several branches flattened in this way (one of 400 
individuals), and have made camera drawings of them. Since the 
results in the different cases are substantially in agreement, I have con- 
cluded that they are significant. One of these camera drawings is shown 
in the figure just referred to. 
To designate individuals in che stock, I have adopted a simple no- 
menclature. The forty-four terminal individuals are numbered from 
l to 44. The successive generations (if I may be allowed to use this 
word in a loose way) are indicated by the Roman numerals from I. to 
XII. Any one individual is indicated by placing the numbers of the 
radial line or lines to which it belongs first, and following this by 
the Roman numeral of the generation to which it velongs. Thus, 
27-30 IV. is an individual near the base of the twig 27-30 and of 
generation IV. Figure 64° (Plate VII.) is a diagram showing the 
1 This species is very similar in general habit to B. avicularia, Linnaeus, and to 
B. turbinata, Alder (Hincks, ’80, pp. 75-80). It differs from the first named spe- 
cies by possessing only one spine, on the outer upper edge, as described by Leidy 
(’55, p. 142), instead of having three, — two outer upper and one inner and upper. 
It differs from Hincks’s diagnosis of the second in having only two “cells” in each 
branch, instead of 3-6 in the upper portions. The form of the avicularium would 
seem to ally it more closely to B. avicularia. 
