1908] - Decapod Crustaceans. 59 
very close to one another and are united a little in front of their 
middle by å short bridge. This bridge is not visible from the lower 
side.") 'Phe oviducets issue a little behind the middle and con- 
tinue in a thin straight tube on each side, without bends, as far as 
the sexual opening on the coxa of the 3rd pereiopod. 
Secondary sexual characteristies: In his work, * Account 
of the Development of Pandalus borealis?) G. O. Sars besides 
diseussing the ditferent larva-stages also gives å description of the 
full-grown individual. It is there stated that *of the 1st pair of 
the pleopoda the inner plate differs conspicuously in the two sexes 
(fig. 4, d and e). In the female it is very densely clothed with 
slender hair, and is drawn out at the tip to å conical naked lappet. 
In the male it is much less hairy, oblong oval in form, and provided 
with åa small subapical lobule car- 
rying the usual retimnacula.” In 
younger females the inner plate 
of the 1st pleopod (fig. 3) is not 
drawn out into any tip, but res- 
embles more that of the males, 
though always without the organ 
of copulation. In fig. 3 we see 
depiected the inner plate (of list 
pleopod) of a specimen 47 mm. 
long. Males of corresponding size Å (å7mn) 
were always furnished with the E SN 
organ of copulation. Further in MEG 
Figu3: 
the case of males we always find 
on the underside near the tip three comparatively strong spines 
(see fig. 4, d). [In Pandalus leptoceros var. Bonmieri we find rather 
more (about 7) similar spines]. - 
In the 2nd pair of pleopods we get the characteristic distine- 
tion between male and female which we have mentioned in the 
case of several other Carids. To the inner branceh of this pair of 
pleopods there will be found fastened, when it is å female, one 
sub-braneh and when it is å male two sub-branches (fig. 4 å and b). 
1) In specimens with larger ovaries the two half parts appear to be quite 
united from the bridge posteriorly, while the separated forward extremities are 
well defined by a groove-like depression.. 
*) Printed in "Report on Norwegian Fishery and Marine Investigations". 
Vol. 1. Kristiania 1900. No. 3 page 39. 
