of the Fishery Board for Scotland. (147 
II. (Fig. 39). The number of spines found on the second maxilla 
drawn was (5 + 3:4 + 5): (3 4+ 3). 
The scaphognathite had nine plumose sete. 
III. (Fig. 61). The spine formula found in this example was (5 + 3: 
5 + 5):(4 + 3). 
There were 18 plumose setie on the scaphognathite. 
IV. (Figs. 40 and 55). The spine formula was (5 + 3:5 +5): (4-+ 3). 
In III. and IV. Zoée then there is one spine more than in 
I. Zoéa. 
The scaphognathite bore 24 sete. 
Mrcatops (Fig. 46). While the general form remains similar, the 
second maxilla has changed greatly in the proportions of its several 
parts. The scaphognathite, which during the Zoéa stages was rapidly 
growing larger, constitutes now the greater part of the appendage. 
The prominent spines of the Zoéa are now replaced by short smooth 
stiff hairs. 
The 2-jointed structure of the second maxilla is still evident. The 
large top lobe has become differentiated into two parts, the upper of 
which is a conical process devoid of hairs, the other a bifid lobe bearing 
the short smooth hairs. The lower lobe is more deeply cleft; on its 
upper half it bears two short smooth hairs, and on its lower, four hairs, 
one of which is provided with several long cilia, while a second has one 
or two serrations. 
The numbers of hairs on the endognath are as follows: (0:3 + 3:3 + 
4):.(2:2 + 2). 
The scaphognathite bears 39 short plumose sete. 
On the surface of the scaphognathite there are three little hairs, and 
on the middle lobe of the endognath, two similar hairs. 
1. (Fig. 59), The top division of the endognath now bears a single 
stiff hair at the middle of its length. The hair arrangement is (1:2 + 
4:6): (3 + 4). 
Of the four hairs on the bottom part of the lower lobe, three are 
ciliated. 
The middle portion of the endognath is now segmented off from the 
rest of the appendage. 
The number of short plumose set fringing the scaphognathite is 
largely increased. On its surface a few short hairs were noticed. 
Tur MAXILLIPEDES, mp, Plates viii., ix., x. 
In the Zoéa two maxillipedes only are functional, viz. the first and 
second pairs. They act as feeding organs, and also through the action 
of their seta-bearing exopodites, serve as the principal organs of locomo- 
tion. ‘The third maxillipede is not fully developed until the Megalops 
stage. 
Spence Bate stated that ‘at the base of these two last pairs of 
appendages [2nd and 3rd maxillipedes]| the germ of the future branchize 
may be distinguished.” 
When the first and second maxillipedes are examined in situ the 
protopodite appears to consist of three joints (fig. 76), This, in view of 
Hansen’s* theory of the 3-jointed protopodite, is of some moment. Two 
of the joints—viz., the long joint and the short one proximal to it— 
are distinct. The “joint” connecting the latter to the thorax is 
tapered, and it is an open question whether it is really a joint of equal 
* Hansen—‘‘ A Contribution to the Morphology of the Limbs and Mouth-parts of 
Crustaceans and Insects,” The Annals and Magazine of Natural History YI.), vol. xii., 
1893, p. 417, 
