36 Crust. 
CRUSTACEA. 
XIPHOSURA. 
Gerstackek, in the above quoted manual, pp. 1081-1088, commences 
his treatment of the Limulidai, which forms in his arrangement the fourth 
order of Crustacea, named Pcecilojpoda. 
ARANEIFORMIA. 
[See Pycnogonidea, in the Arachnida, infr.l] 
