58 



the same scale, and a comparison between these two ti^ures offers a pretty good ilhisti-ation 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 pi'oniinent 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 mate must grow to some extent, for, as males of small size in this (as in 

 other) species are pretty rare, we liave good reason to suppose that this growth is compara- 

 tively rapid. 



TJie female apparently imsses through a pupa stage. I have found three such »pupse« 

 altogether, which were all about the same size; the specimen illustrated in pi. IV, fig. 1 f 

 is '174 ram. long. The body is ovate, somewhat flattened and attached at the ft-ont by a 

 broad adliesive 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: antennulae (a), antennae (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 tJie scarcely developed mouth, 

 the maxiUce and the folded maxillipeds of the young female. So the skin of the larva has 

 acquired the ajjpearance 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 -201 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, Sphmr. chinensis and closely allied species, which, together with Sphtpr. Leuckartii, 

 form a small gi'oup, whicli I have named after this species. Salensky (in his op. cit.) has 

 described and illustrated several stages of development of Sphrer. Leuckartii, and his obser- 

 vations agree very well with mine, only I have lieen able to make some additional statements. 

 The pupa is ovate, sometimes naked on its anterior part (pi. III. fig. 2 f), though, as a rule, 

 it has only a smaller naked spot in the luidst of the ventral surface (pi. II, several figures); 

 otherwise it is ail over pretty closely covered with rather short liairs; 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. (J e), by which the 

 pupa is liinged, 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 depres.sion 

 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 abcjve- 



