- 472 Scientific Intelligence. 
to disregard the more direct relations of Limulus with the Ento- 
mostraca (to which he as well as Dana refers the Merostomata) in 
order to compare it with the young of the Decapods. Professor 
Dana’s views are fully sustained by Owen in a recent paper on the 
anatomy of Limulus read before the Linnean Society of London.t 
Dr. Packard makes four orders of Branchiopoda, which he re- 
gards asa subclass, as follows: Ist, Cladocera, 2d, Merostomata, 
including the suborders, Xiphosura and Eurypterida, 3d, Trilo- 
is discussed. 
Eurypterida and Trilobites, as one of the primary groups of om 
tacea, while others would separate them entirely from the ris: 
§. LS. 
* U.S. Expl. Expd., Crustacea, p. 40. 
+ Reported in Nature, for Dec. 28, 1871, and Jan. 25, 1872. 
