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 -02 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 » pupae « 

 altogether, which were all about the same size; the specimen illustrated in pi. IV, fig. If- 

 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: antennidse (a), antennas (c), 

 maxillae, maxillipeds (g), first pair of natatory legs (m), second pair of natatory legs (n) and 

 abdomen (o), 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 maxillae and the folded maxillipeds 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. Pig. 1 g in pi. 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 Sphceronella 

 danica, Splicer, chinensis and closely allied species, which, together with Splicer. Leuckartii, 

 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 Splicer. 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 (pi. Ill, fig. 2 f ), though, as a rule, 

 it has only a smaller naked spot in the midst of the ventral surface (pi. 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 (pi. 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 (pi. II, fig. 4 d and fig. 4 e). On the posterior half of the above- 



