MORPHOLOGICAL NOTES. 31 



In the Xiphocephalidas on the other hand there exist no ovi- 

 tectrices, but the eggs on leaving the oviduct are fixed on the under side 

 of the body, probably by means of some kind of cement, which is pos- 

 sibly secreted from some of the strongly developed glands in the joints 

 of the perasopoda. In any case the manner of carrying the eggs arid 

 embryos is very remarkable, and, as far as I know, has not been pre- 

 viously observed (fig. 47). A different number of eggs are fixed under 

 the different segments: under the first I have never observed a single 



Fig. 48. The fourth peraeonal segment Fig. 49. The sixth perseonal segment 



, of Xiphocephalus Whitei. Q. of Xiphocephalus Whiiei. 



egg, under the second three or four pairs are fixed at equal intervals, 

 under each of the third and fourth four or five, under the fifth seven 

 or eight, under the sixth five or six pairs and none under the seventh, 

 one female thus carrying in all from forty to fifty eggs or embryos. I 

 have observed very young eggs thus placed, they being in fact in the 

 third or fourth stage of division, and quite globular (fig. 48), as well as 

 embryos just on the point of breaking the egg membrane (fig. 49), the 

 form of the egg in this case being elongate-ovate, and the young being 

 provided with six pairs of peraeonal legs, distinctly developed and ar- 

 med with strong claws. 



The first and second pairs of perceopoda are developed into strong 

 grasping or prehensile organs, and show in the different genera almost 

 all the modifications of such organs which are to be observed among 

 the other Hyperids. 



We meet with the less complicated form in the first pair of pe- 

 rseopoda of Simorhynchotus (fig. 50), that is to say: 



1. The folding hand (fig. 50), in which the carpus is only a little di- 

 lated, and has a more or less rounded hind margin, so 

 that the metacarpus can be doubled up along it so as 

 to impinge against its hind margin, the dactylus thus 

 coming in contact with the tibia. 



