58 
the same scale, and a comparison between these two figures offers a pretty good illustration of 
the different sizes seen from below). Fortunately I have found a single male which without 
any doubt, judging from its inward and outward condition, is quite recently hatched, and 
which is only “18 mm. in length, consequently O02 mm. longer than the above-mentioned 
cephalothorax; now, if we consider the prominent frontal border in the male and its rather 
more elongate shape, this slight difference is accounted for. The result is, that immediately 
after hatching, the male must grow to some extent, for, as males of small size in this (as in 
other) species are pretty rare, we have good reason to suppose that this growth is compara- 
tively rapid. 
The female apparently passes through a pupa stage. I have found three such »pupe« 
altogether, which were all about the same size; the specimen illustrated in pl. IV, fig. 1f 
is 174 mm. long. The body is ovate, somewhat flattened and attached at the front by a 
broad adhesive plate (s). In the illustration several limbs are seen, but, on closer examina- 
tion, it appears that all these organs are those of the larva: antennule (a), antennz (c), 
maxillz, maxillipeds (¢), first pair of natatory legs (m), second pair of natatory legs (n) and 
abdomen (0), in other words, the animal is enclosed in the skin of the larva, whose appen- 
dages and abdomen are not only emptied of their contents, but have shrunk, so as to be almost 
unrecognisable. There is no mouth. Under the skin we see the scarcely developed mouth, 
the maxille and the folded macxillipeds of the young female. So the skin of the larva has 
acquired the appearance of a pupa; a real pupa does not exist. The animal cannot possibly 
take any nourishment. Fig. 1g in pl. IV represents a young female that has just burst 
the ventral side of the »skin of the pupa«, whereas its ragged dorsal part still hangs on to 
it; this specimen was only -207 mm. in length, consequently only ‘034 mm. longer than the 
pupa represented. This young female was still attached by the adhesive plate (s) of the skin 
of the larva. 
A pupa deviating from those of the above-mentioned types is found in Spheronella 
danica, Spher. chinensis and closely allied species, which, together with Spher. Leuckarti, 
form a small group, which I have named after this species. Salensky (in his op. cit.) has 
described and illustrated several stages of development of Spher. Leuckartii, and his obser- 
vations agree very well with mine, only I have been able to make some additional statements. 
The pupa is ovate, sometimes naked on its anterior part (pl. III. fig. 2f), though, as a rule, 
it has only a smaller naked spot in the midst of the ventral surface (pl. II, several figures); 
otherwise it is all over pretty closely covered with rather short hairs; from the anterior 
end, which is always narrower or more pointed, proceeds a tuft of longer hairs, and in the 
midst of these is a rather short thread, which ends in a disk (pl. II, fig. 6 e), by which the 
pupa is hinged, either to one of the plates of the marsupium, to the inner side of the basal 
joint of a leg, or to a gill. (Usually this frontal thread proceeds from a small depression 
with flat bottom, however, in one case, I have noticed that it proceeded from a stouter, 
short, cylindrical eminence (pl. II, fig. 4d and fig. 4e). On the posterior half of the above- 
