NOTES AND MEMORANDA. 159 



Development of Crustacea. — At a recent meeting of the 

 Geological Society a paper was read, entitled " Further 

 Remarks on the Relationship of the LimulidcB (Xiphostcra) 

 to the Eurijpte7'idce and to the Trilobita." By Mr. Henry 

 Woodward, F.G.S. In this paper the author described the 

 recent investigations made by Dr. A. S. Packard, Dr. Anton 

 Dohrn, and the Rev. Samuel Lockwood upon the develop- 

 mental history of the North American Kingcrab {Limulus 

 Polyphemus), and discussed the conclusions as to the 

 alliances of the 'X.iphosura and EurypteridcB, and to the 

 general classification of the Artliropoda, to which the results 

 of these investigations have led Dr. Dohrn and some other 

 Continental naturalists. According to this view% the 

 Xipliosara and Eurypteridce are more nearly related to 

 certain Arachnida (the Scorpions, «&c.) than to the Crustacea; 

 and this opinion is further supported by the assertion of Dr. 

 Dohrn, that in Limidus only one pair of organs (antennules) 

 receives its nerves from the supraoesophageal ganglion, and 

 that the nature of the underlip in Limulus differs from that 

 prevailing among the Crustacea. Dr. Dohrn also re- 

 cognises the relationship of the Merostomata to the Trilobites, 

 as shown especially by the development of Limulus, and 

 considers that the three forms {Limulidcs, Eurypteridcs, and 

 Trilohita) should be combined in one group under the name 

 of Gigantostraca, proposed by Haeckel, and placed besides 

 the Crustacea. The author stated, on the authority of 

 Professor Owen, that Limulus really possesses two pairs of 

 appendages which receive their nerves from the supra- 

 oesophageal ganglion ; that, according to Dr. Packard, the 

 young Limulus passes through a Nauplius stage while in the 

 egg ; that no argument could be founded upon the lower lip, 

 the condition of which varied extremely in the tliree groups 

 proposed to be removed from the Crustacea ; and he main- 

 tained that even from the ultra- Darwinian point of view 

 taken by Dr. Dohrn, the adoption of his proposal would be 

 , fatal to the application of the hypothesis of evolution to tho 

 class Crustacea. Professor T. Rupert Jones, Professor 

 Macdonald, and others, having made some remarks, Mr. 

 Woodward, in replying, drew attention to the diagrams of 

 the embryo and larva of the recent Limulus , comparing them 

 with Limulus of the Coal-measures, NeoUmulus of the 

 Silurian, and also with the larval stages of the Trilobites, 

 discovered by Barrande. He pointed out the strong resem- 

 blance which the fossil forms offer to the early stages of the 

 modern King-crab, and expressed his assent to the proposal 

 of Dr. Dohrn to bring tlie Trilohita, if possible, nearer to the 



