1871.] WOODWARD XIPH09UEA. 63 



the embryo and larva of the recent Limulus, comparing them with 

 lAmulus of the Coal-measures, Neolimidus of the Silurian, and also 

 with the larval stages of the Trilobites discovered by Barrande. 

 He pointed out the strong resemblance 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 the Trilobita, if possible, 

 nearer to the Merostomata. If, however, the Trilobites have true 

 walking-legs instead of mouth-feet (gnathopodites) only, they would 

 be more closely related to the Isopoda. He showed from his tabular 

 view of the Arthropoda that the known range in time of the great 

 classes is nearly the same, and therefore affords no argument for 

 combining the Merostomata with the Arachnida ; but, on the con- 

 trary, he considered that the Trilobita were, with the Entomostraca, 

 the earliest representatives of the clasa Crustacea, and therefore 

 could not be removed from that class. 



