Plate XIII. 

 Figs. 33 and 34. Longitudinal sections tlirougU the liead of a young spider 

 about to batfli. 



Fig. 33. Showing the median eyes, and the brain which occupies a 

 relatively greater portion of the cephalothorax than is the case with the 

 adult spider. 



Fig. 34. Showing the mouth, infJi.; oesophagus, vcs.; the cheliceral muscles, 

 runs.; the procepbalon, Jji:; and the postcephalon, s. o. (/., 1-12. 



