139 
cephalic segment is seen to be very much depressed. The forehead is extremely narrow (Plate 
XLII, fig. 2). The distal end of the last thoracic segment is broadly rounded below, then 
slightly emarginate as it rises to join the dorsal line. The rostrum consists of a bifurcate papilla 
without filaments (Plate XLIII, fig. 4). 
The combined length of the abdomen and furca is contained three and one-half times 
in the total length of the cephalothorax, from the frontal margin to the end of the last 
thoracic segment. The genital segment is very slightly asymmetrical. It is fully one and a half 
times longer than the combined length of the next two segments. The ventral surface of the 
segment is produced into a rounded knob. The second segment is equal to two-thirds of the 
length of the third segment. The third segment is equal to one-third of the length of the 
genital segment. The furcal joints are small. They are rather longer than broad, and are nearly 
as long as the anal segment (Plate XLIII, fig. 1). 
The antennules are composed of twenty-five joints and reach to the end of the furca. 
The exopodite of the antennae is eight-jointed. It is distinctly less than half the length 
of the endopodite. 
The biting edge of the mandible is furnished with three pairs of teeth (Plate XLIII, fig. 6). 
The exopodite of the maxillae is furnished with two moderately long setae. 
The two pairs of maxillipedes are similar to those of the previous species. 
The five pairs of feet are also similar to those of Auguptilus placitus. The outer edge 
spine on the first joint of the exopodite of the first pair of feet does not reach the middle of 
the third joint. 
Male — length 7,6 mm. 
The male resembles the female in general appearance. The abdomen is composed of 
five segments. The rostral papilla is more bifurcate, and the apex of each ramus is pointed 
(Plate XLIII, fig. 8). The left antennule is prehensile. 
The antennae, mandibles, maxillae and maxillipedes are similar to those of the female. 
The first four pairs of feet are similar to the first four pairs of the female. 
The joints of the exopodite of the fifth pair are very short. The last joint of the right 
exopodite is somewhat narrowly rounded at the apex. The inner distal end is furnished with 
a short curved spine. The joint is also furnished with one outer marginal, and one inner marginal 
spine. The last joint of the exopodite of the left foot is broadly rounded at the apex. The 
distal end bears two spines. The joint is also furnished with one outer marginal setae. The 
proximal end of the inner margin of the second joint of the left exopodite, bears a small 
spiniform process which is distinctly bifurcate at the apex (Plate XLIII fig. 10). 
This species is easily identified by the very depressed cephalic segment, and by the 
pointed forehead when seen from the side. The rather feebly bifurcate papilla of the female 
rostrum, and the more pointed rami of the male, along with the spiniform process on the inner 
margin of the second joint of the exopodite of the left fifth foot, are also characters that help 
to separate this species from any of the others. 
Occurrence. — Two males and one female were found in the plankton collected 
with the HeEnseEn vertical net at the following stations. 
139) 
