REPORT OF THE DIRECTOR I915 39 



transparent spot for the reception of light intensities, and in the 

 last Devonian trilobites it apparently has lost its visual function 

 and disappeared as a tubercle. This investigation will be published 

 in detail during the present year, together with observations of 

 the true suture-line in Cryptolithus (Trinucleus) and other genera 

 of the order Hypoparia. 



