of the Fishery Board for Scotland. 77 
FourtH Psreroron, dper., figs. 42, 52, and 45. 
The endopodite shows five joints. On the propodite the spines have 
very large serrations on their distal halves, and smaller teeth on their 
proximal halves. On the other side the spines have small serrations. 
There are two kinds of serration on the long spine of the dactylopodite. 
At the base of this spine there is a tooth on the dactylopodite. 
The exopodite had 24 (26) sete. 
Four gills and one epipodite are connected with this limb. 
Firta Pereropop, dper., figs. 42, 52, and 45. 
On the endopodite there is a little tooth at the base of the terminal 
spine. 
The exopodite had 22 setze. 
One gill, a pleurobranch, is connected with the fifth pereiopod. 
LBRANCHIA. 
The number and the arrangement of the gills of the first stage zoéa 
are similar to the condition in the adult. Two of the gills, however, are 
here rudimentary. In fig. 49, pl. ii, the branchial cavity is shown, 
The gills are represented in the positions they occupy, but are shown 
much more slender than they actually would appear. ‘They are packed 
close together. The division of the gills into podobranchiz, arthro- 
branchiz, and pleurobranchie is clearly shown in the case of the majority 
of the gills, but some there are which, from their position, might be 
regarded as pleurobranchs. In the adult, however, they are arthro- 
branchs, and very probably are arthrobranchs in the larva. They are 
the gills on the top row of the arthrobranchs in the following scheme. 
The Table exhibits the arrangement of the gills in the first zoéa stage 
(vide fig. 49). The gills are arranged in the branchial chamber in four 
rows. The highest row consists of four pleurobranchs belonging to the 
second to fourth pereiopods. The next row consists of five arthrobranchs 
which are connected with the third maxillipede and first four pereiopods. 
The third row comprises another set of five arthrobranchs attached to 
the same appendages. The fourth row includes six prodobranchs, borne 
by the second and third maxillipedes and the first four pereiopods. The 
first and last of the series are rudimentary gills. Each of the above- 
mentioned appendages, with the exception of the fifth pereiopod, has an 
epipodite. On the coxopodite of the last pereiopod there is a small process 
which may represent the epipodite. 
Herrick says that in the American lobster there is no rudimentary gill 
attached to the second maxillipede. 
In Fig. 49 the following letters are used :— pl.-6r., Pleurobranch ; 
ar.-br., Arthrobranch ; pd.-br., Podobranch. 
| TABLE, 
