172 W. Lilljeborg on the Genera Peltogaster and Liriope. 
The skin is very delicate, smooth, and very transparent. The 
organ of adhesion is placed behind the middle of the body. It 
is very small, furnished with a very short neck, and with mar- 
gins which are but little folded outwards, and scarcely radiated. 
The colour is the same as that of the skin, which forms, as in 
the preceding species, an elevated ring round the organ of ad- 
hesion. The anterior opening is scarcely visible ; it is not placed 
at the middle of the extremity of the body, nor surrounded by a 
a raised and folded margin. The colour is whitish-yellow or 
light red. 
The young animal or Jarva (fig. 16), while enclosed in the 
egg or just escaped from it, greatly resembles that figured by 
Lindstrém. It is not yet sufficiently developed to enable the 
germ of the antennz to be seen in the apophyses of the anterior 
part of the body. Here we see only a streak formed of the same 
material as the antennz. These apophyses were applied against 
the margin of the body, and were visible only after strong pressure. 
As found by Messrs. Spence Bate * and Darwin in the larve of 
the Cirripedes, they certainly issue in this larva from the lower 
side of the body, as do also the antennze which are formed in 
them ; so that they do not belong to the dorsal buckler. The 
posterior part of the body usually wanted the two little promi- 
nent parts of the lower surface which occur in the specimen 
figured. They might therefore be regarded as a mark of a more 
advanced development. The spot of pigment in the place of the 
eye, being of a reddish-brown colour, can only be a rudimentary 
eye. It has much resemblance to the eyes of the larve of the 
Copepoda. 
This species has been found on Pagurus chiracanthus and P, 
levis on the coasts of Norway. It does not appear to be rare. 
With regard to the relation between Pachybdella and Pelto- 
gaster, and between these and those Crustacea most nearly allied 
to them, the author remarks that his descriptions prove that the 
animals differ from each other so much as to belong not only to 
distinct genera, but also to two distinct families. Pachyhdella is 
far higher in point of development than Peltogaster ; and in its 
structure the former presents more analogy with the ordinary 
Cirripedes than the latter. On examining the opened Pachy- 
bdella (fig. 7), it is found to have a mantle or sac like the other 
Cirripedes ; this sac surrounds the thick and fleshy body, which, 
although much metamorphosed, presents some resemblance in 
its form to that of the body (thorax) of a Balanide when all the 
* On the Development of the Cirripedia, Ann. and Mag. of Nat. Hist. 
2nd series, vol. viii. p. 324. 
