78 A. J. HANSEN. 
(Stebb.) (N.abyssorum [Bedd.]) is so closely allied to one of 
my European species of Dynamene that the same arrange- 
ment is to be expected. In Cerceis (M.-Hdw.) (an undescribed 
species rather allied to C. tridentata (Hasw.) has been 
examined) the marsupium and the development of the brood 
is completely as in Dynamene; Haswellia (Miers) is so 
closely allied to Cerceis that the development is in all 
probability quite similar.—In Cymodocella a somewhat 
different arrangement is found; some specimens of C.egregia 
(Chilt.) have been examined. The marsupial lamellee are only 
so long that they overlap each other rather little with their 
ends. The brood is developed anteriorly in the marsupium, 
posteriorly in an enormous external pouch; the upper wall 
of this pouch is the ventral surface of thorax behind the 
origin of fourth pair of legs, while its lower wall is a rather 
thin lamella fixed inside the base of the four posterior pairs 
of legs and in front of abdomen, with its free margin ex- 
tended between the base of the two legs of fourth pair. 
That this wall is a foiding of the skin from behind goes 
without mention. At least one haif of the eggs or young 
are found in this pouch; the other portion is covered by the 
marsupial lamelle, which also, seen from below, overlap the 
front part of the wall mentioned. In a female I counted 
thirteen rather large oblong eggs. From want of females 
with brood of Amphoroidea(M.-Edw.) and Dynamenella 
(n. gen.) nothing can be stated on the propagation in these 
genera. 
Of the twelve genera belonging to the platybranchiate 
Spheromine I have been able to study the propagation in only 
five genera, but these are fortunately representatives for the 
four sections constituting the group. 
Of the section Campecopeini Parasphewroma prominens 
(Stebb.) has been examined. The marsupial lamelle overlap 
each other somewhat at the mesial line; the marsupium is 
empty, the brood being enclosed in pouches, the entrances to 
which are longitudinal slightly oblique slits situated at the 
base of first and second pairs of marsupial lamelle. As far 
