370 Miscellanea Zoologica. 
claws, sometimes aided by smaller subsidiary ones moving in the 
same direction. The fifth segment is small or rudimentary, cylin- 
dric, without appendages of any sort, but perforated at the end with 
the anus, which is an oval perpendicular aperture with tumid lips : 
this segment is all that remains of the abdomen, which meets with 
its extremest reduction in this tribe of crustaceans. 
The Pycnogonidae are all marine animals. They conceal them- 
selves among sea-weed and corallines between tide-marks ; under 
stones within the lowest tide-line ; and they are occasionally dredg- 
ed from deep water. Their motions are remarkably slow, and as 
it were painful to our apprehension j hence it is obvious that their 
prey must be either dead animal matter, or living animals as habe- 
tous and defenceless as themselves, an inference which is confirmed 
by the conformation of the oral organs. We are told that they live 
principally on the fish of bivalve shells,* which they insidiously 
enter as these lie gaping in their usual fashion when no danger 
threatens. Some assert that the Pycriogonum is parasitical on the 
whale, but perhaps the resemblance which this animal has to the 
Cyamus ceti t may have deceived the observers, and given rise to 
the remark, for it is certainly common on our shores where there 
are no whales; and Fabricius mentions that in Greenland it is found 
under stones on the shore, just as with us. The females are appa- 
rently fewer in number than the males, or are at least much seldomer 
met with : they are distinguished, as Baster first of all ascertained, 
by having a pair of spurious legs in addition to those common to both 
sexes, which originate from the inferior anterior margin of the first 
thoracic segment, and are appropriated to the purpose of holding 
and carrying the eggs. These are collected into globular masses en- 
veloped with a thin skin or membrane, each mass firmly adherent 
to the spurious or oviferous leg, and consisting of a congeries of nu- 
merous round ova. There are several masses of these eggs in all 
the genera excepting Pycnogonum, in which the eggs form a single 
broad square membrane laid under the body. The changes which 
the individual may undergo from its birth to maturity are un- 
known. 
* " Mytilorum testasque perietratet exhaurit J. G. K6nig,"in Lin. Syst. Nat. 
1025. Of his Pycnogonum grossipes, O. Fabricius says, " Vescitur insectis et 
vermibus marinis minutis ; quod autem testas mytilorum exhauriat, mihi igno- 
tum est, dum nunquam intra testam mytili illud inveni, licet sit verosimile sa- 
tis." Faun. Groenl. 231. 
f This resemblance misled Fabricius when he put the Cyamus and Pycno- 
gonum in the same genus. 
