342 ARACHNOWEA AND PALyEOSTRACA. 



IncertcE Sedis. 

 Pantopoda or Pycnogonid^. 



These are marine Arthropods, sometimes called sea spiders. Their 

 affinities are uncertain, but perhaps they may be ranked between 

 Crustaceans and Arachnoids. Many climb about seaweeds and hydroids 

 near the shore, but some live at great depths. The body consists of an 

 anterior proboscis, a cephalothoracic region with three fused and three 

 free segments, and an unsegmented rudimentary abdomen. In most 

 there are seven pairs of appendages, into five of which outgrowths of 

 the mid gut extend. The se.xes are separate, and the males usually 

 carry the eggs attached to the third pair of appendages. The larvte are 

 at first unsegmented, with three pairs of appendages. 



Examples : — Pycnogonum, Nymphon, Ammothea. 



