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 Pycnogonidte 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 ; — 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 Pycnogonum 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 penetrat et exhaurit. J. G. Konig,"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. 



