72, TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
Each of these consists of an outer ‘ opercular’ lobe and 
an inner lobe. In the male the inner margins of the 
outer lobes of the first pair may, or may not, be produced 
into short spinous processes; the imner margins of the 
second pair are produced into two long slender styles for 
copulatory purposes. 
The terminal segment or telson is composed of the 
last two segments of the metasome, which are fused to 
form a rather broad terminal segment. ‘The posterior 
edge is evenly rounded; the lateral portions are acuminate 
and subtend a sinus in which the terminal pair of uropoda 
arise. Hach of the terminal uropoda consists of a fairly 
stout basal portion, from which the styliform appendages 
arise. The anus is a longitudinal slit on the ventral side 
of the terminal segment. 
The external apertures are—the mouth, the openings 
of the maxillary excretory organs on the protopodites of 
the second maxillae, the openings of the oviducts at the 
base of the fifth pair of pereiopods, or of the vasa 
deferentia at the posterior border of the ventral side of the 
seventh thoracic segment, and the anus. 
APPENDAGES. 
The first pair of antennae (PI. II., Fig. 1) ay be truly 
called antennules, as they are extremely small, measuring 
a little over 1 mm. in length. They are situated internal 
to, and at the base of, the second antennae. ‘They are 
triarticulate, the terminal joint being quite rudimentary 
and bearing two terminal groups of small setae. 
The second pair of antennae (1. II., Fig. 2) are long, 
attaining a length of 25 mm. in the male and 14 mm. in the 
female; when folded back they extend to the posterior 
border of the fourth thoracic segment. The protopodite 
is composed of five joints, the fourth and fifth being the 
