i Eide i 
am VG Oe ee EA EN TS 
SP ie aL ac baal ae tA a i ia ea ao SIS ea a lel 
W. Lilljeborg on the Genera Peltogaster and Liriope. 173 
appendages (which have completely disappeared in Pachybdella) 
are removed. In Pachybdella, as im the Cirripedes in general, 
there are external and ramose “ ovarian ceca” situated between 
the mantle and the body (thorax). In external form it does not 
differ much from the male Cryptophialus of Darwm*. The state 
of Peltogaster is quite different. The external covering of the 
body, or the skin, may be compared with the mantle of the ordi- 
Cirripedes,. having a second aperture as in Pachybdella. 
But this mantle does not surround a separate fleshy body, and 
it only contains a cavity lined with a delicate membrane. In 
this cavity are sometimes accumulated the food which the animal 
has probably sucked from its host ; and on the bottom of it there 
are the two sacciform primitive ovaries, which become inflated 
as they are developed, until they present two sacs of eggs com- 
pletely filling the cavity. As there are analogies between Pa- 
chybdeila and the normal Cirripedes, others may be found 
between Peltogaster and the abnormal Cirripedes, such as Dar- 
win’s Proteolepas. The external form of the latter has much 
_ resemblance to that of Peltogaster, except that it has the body 
segmented. Like Peltogaster, it has no distinct stomach ; and 
almost the whole cavity of the body is occupied by a large sac 
of eggs (perhaps by two). Outside this sae there are also two 
sacciform ovaries, resembling the two primitive ovaries of Pelto- 
gaster. From these comparisons it is evident that if Pachybdella 
and Peltogaster are to be regarded as inferior to all the other 
Cirripedes, and consequently to all other Crustacea, Peltogaster 
is the lowest of all. 
They appear generally to show the greatest affinity with the 
order Apoda of Darwin; but the segmentation of the body, the 
appendages of the mouth, and the certain degree of permanence 
of the prehensile antenne in the Apoda, distinguish them from 
Peltogaster and Pachybdella. To the latter the author gives the 
name of Cirripedia Suctoria, from their sucking their nourish- 
ment from the animal to which they are attached. If the Cirri- 
pedia be placed in a line parallel with the other Crustacea, the 
Cirripedia Suctoria must be regarded as analogous to the Ler- 
neide amongst the latter. 
* The internal structure of Cryptophialus appears to have more resem- 
blance to that of Peltogaster. As Darwin says of certain males (vol ii. 
p- 23), that they merely represent “‘ bags of spermatozoa,”’ it may be said 
of the perfectly developed Peltogasters that they are only bags of eggs. 
[To be continued. } 
