548 LEPADID.E. 



section of the thorax is made, and the stomach removed, it- 

 can be most plainly seen that there are no vesiculse semi- 

 nales or testes. Mr. Hancock has remarked on the 

 absence of the usual probosciformed penis. The male of 

 Alcippe will be subsequently described in detail. The 

 female organs differ in no respect from those of other mem- 

 bers of the family, excepting in so far that the layer or 

 mass formed by the ovarian caeca (c) does not lie transversely 

 to the longitudinal axis of the whole animal, but longi- 

 tudinally under the horny disc. The ovigerous fraena are 

 largely developed, but serve, as previously stated, as branchiae, 

 and not for their proper function of giving attachment to 

 the ovigerous lamellae. The ovigerous lamella is single, 

 and nearly corresponds, in size and shape (as would ensue 

 from the manner of its formation) to the under side of the 

 horny disc. The ova are broadly oval, and rather above 

 T ioth of an inch in length. 



Metamorphoses. — The larva in the first stage has been 

 fully described and figured by Mr. Hancock : it differs in 

 no essential respect from other larvae of the family. Mr. 

 Hancock overlooked the inferior minute antennae. With 

 respect to the larvae in the last stage, or pupa, I obtained 

 several specimens attached to the disc of the female, and 

 which were on the point of being developed into males ; 

 and another specimen identical in all respects, but attached 

 independently to the shell of the mollusc, and which, there- 

 fore, I have every reason to suppose, would have been 

 developed into a female. In any case these pupae may 

 be conveniently here described (PI. 23, fig. 16.) They 

 are '025 of an inch in length ; they are of the usual shape, 

 with the anterior end not very blunt and the postero- 

 ventral surface somewhat produced. The whole carapace 

 or shell is very thin and smooth. There are six pairs of 

 thoracic natatory legs, situated far back towards the pos- 

 terior end of the body ; each leg has the usual articulations, 

 and the two rami their usual long but not plumose spines ; 

 the presence of the legs deserves notice, considering the 

 rudimentary and modified state of their homologues in the 

 mature animal. The abdomen differs considerably from 

 the same part, as far as I have seen, in other pupae; it consists 



