Note ox the Eggs of this Trilobite. 67 



over fifty eggs scattered more loosely in the spar. In a longitudinal section 

 of another individual, a cluster of eggs, closely agglomerated, occurs within the 

 visceral cavity, between the eight posterior segments of the thorax and the ven- 

 tral membrane. Three transverse sections, from different individuals, show the 

 ova within the visceral cavity. In one, cut just posterior to the hypostoma, the 

 ova are near the dorsal shell. The other two are cut across the thorax. The 

 ova are in the spar which fills the axial appendages and visceral cavity. They 

 seem to be scattered, as if the organic matter, now replaced by the spar, 

 was in such a condition as to permit of their passing from the visceral cavity 

 down into the cavities of the axial appendages. 



The method of aggregation of the ova, and the close resemblance in form of 

 the individual bodies forming the clusters, as figured by Barrande,* to the 

 ova found within the Trilobites, indicates that both are the ova of the Trilobite. 

 If the above view is sustained, then the manner of the oviposition of the Trilo- 

 bite is different from what has hitherto been supposed, as the clusters of ova 

 mast have been deposited something as the Argulus deposits its eggs, and not 

 dropped into the water, as by Simulus or Branchipus. The relation of the ova 

 to the position they occupied in the living animal will be spoken of in a future 

 article, as most of the sections thus far obtained show that they have been dis- 

 placed, and forced into the various positions in which they are found. 



* Op. cit. ; Supplement, PI. 11, Fig. 6 ; PI. 18, Figs. 30, 32 ; PI. 35, Figs. 21, 23. 



