62 



antennulae; according to this interpretation they ought to have been marked »a« in the 

 illustration, and the antennae not »a«, but »c«. Somewhat behind the fixation-thread I 

 found a pair of bodies (z) which were situated at a short distance from each other and 

 looked as if they were pasted on; whether they belong to the animal I do not know, though 

 I suppose they do, as one of the specimens was provided with both these small bodies, the 

 other with one of them. The hindmost part of the body and a smaller part of the surface 

 surrounding the large ventral process, are provided with a number of rather short hairs. 



Fig. 1 c in pi. XII shows the stage of development which immediately precedes the 

 afore-described stage. The only specimen found is - 24 mm. long; the scale of enlargement 

 is like that of the last stage. The body has about the same shape, and the mouth, the 

 maxillulae, maxillae (f), maxillipeds (g) and antennas (a) have a similar structure and position ; 

 but the antennulse (t) are placed further backward than in the more advanced stage, almost 

 behind the middle of the animal ; their form is somewhat vague. The dorsal fixation-thread 

 (u and v) proceeds at some distance behind the middle of the median line of the back; it 

 is almost constructed as in the older stage, but is considerably longer, and its distal part 

 is much less stout. The crescent of the genital aperture (r) is not found on the dorsal, but 

 on the ventral surface, near the posterior extremity of the body. The odd ventral process 

 (x) is situated almost in the middle between the base of the maxillipeds and the posterior 

 end of the body; it is rather short and very stout and broad; it is indeed a projection, 

 which has on its top a well-developed mouth (y) with mandibles, and whose sides and front 

 part are provided with chitinous lists, like those which surround the mouth of the pupa in the 

 group Splicer. Leuclcartii; on the side this skeleton forms a figure (y'), which, seen as in 

 the drawing obliquely sideways, looks very much like a maxillula; however, on closer 

 examination it turns out not to be any appendage. Now we should feel much inclined 

 to think, that the pupa just described does indeed represent an animal provided with an 

 apical mouth in the act of breaking out of the skin of the pupa, the mouth of which is 

 marked »y«, however, repeated and careful examinations of the admirably preserved pupa, 

 which I have been able to roll under a glass-cover, and to study from all sides, give the 

 result, that it is really an animal with a larger apical and a smaller, hut very well developed 

 ventral mouth, the latter of which disappears in the following stage, only leaving the odd 

 ventral process x in fig. 1 d. That the existence of two mouths in the same animal is per- 

 fectly incomprehensible to me. goes without saying. — The whole animal is naked. 



Finally I have found two badly preserved, infinitety small pupae of about equal size, 

 one of which is illustrated in pi. XI, fig. 3 i. The body is '136 mm. long, shortly ovate, 

 with a well-developed mouth at the rather pointed front extremity, and a little more back- 

 ward on the ventral side maxillae and maxillipeds, the former of which being of pretty good 

 size, but with thin walls and of a somewhat vague form, whereas the maxillipeds are almost 

 smaller than the maxillae, 2-jointed, and very weak. Beneath the skin, between the maxillse, 

 is seen a pretty large, anteriorly inflexed ring (x), which seems to be the beginning of a 



