264 BOPYRTD^E. 



young were totally unlike the Cirriped-formed larvae of 

 the Peltogaster, and that they exactly resembled Rathke's 

 Liriope ; thus proving that the body of the supposed 

 Peltogaster of Rathke, in which the Liriopes were found, 

 was, in fact, the superposed body of the second parasite, 

 or, in other words, that the female of Liriope was now 

 discovered, that Rathke's animals were the young of that 

 female, that Dana's Cryptothir, found upon a Balanus, 

 was either the young or male of a closely-allied animal, 

 and that Cavolini's parasite, found upon Portunus, was to 

 be referred to the same group. As the minute and active 

 Liriopes were found, both by Rathke and Lilljeborg, 

 within the egg-sac of the parasitic female, the question 

 arises (and is still undetermined) whether these little 

 creatures are exclusively young males, or are the larvae - 

 form of both sexes ? and whether the adult male does or 

 does not retain its larva shape almost unaltered during 

 the whole of its life ? Analogy with the stages of de- 

 velopment of the Bopyridce, and especially with those of 

 the following species, would lead us to adopt the opinion 

 that in their earliest stages both sexes of this genus 

 are alike in form, and that whilst the female gradually 

 loses the articulated character, together with all the 

 external appendages of the body, the male retains much 

 of its larva condition. Such is the opinion of Lilljeborg, 

 who has argued the question at considerable length, and 

 such appears probable on taking into consideration the 

 comparative characters of the young and adult males of 

 Bopyrus squillarum (as represented in our figures in p. 218), 

 of Gyge galathea (p. 225), and of lone thoracica (p. 254), 

 and those exhibited in our several figures of the young 

 or males of this species, given by Rathke and Lilljeborg 

 copied as above, and our own as given in the cut at the 

 head of this article. According to Lilljeborg, however, 



