344 Mr. Lubbock on the Development of Lonchoptera. 



sent case the ganglionic mass is cylindrical, or somewhat pea- 

 shaped, showing internal traces of a double column, with fibrous 

 prolongations to the nerves, and intermediate cellular (?) matter. 



There seemed to be eleven pairs of nerves. I could indeed 

 only make out ten nerves, but between the seventh and eighth 

 was a space, which would about leave room for another nerve; 

 in the centre of which, moreover, was a tracheal tube exactly like 

 that which accompanies the other nerves. The commissures are 

 short and broad, or rather the oesophagus may be said to pass 

 through a small orifice between the two great supra-oesophageal 

 ganglia. 



DESCRIPTION OF PLATE. 



1. Outline of larva seen from above. X 30. 



a a and h b. The lines along which the larval skin splits to admit of the 

 escape of the perfect insect. 



c. Anterior spiracle. 



d. Posterior do. 



e. Longitudinal trachea. 

 ff. Two transverse branches, 



g. Minute orifice on the fourth segment. 



2. First three segments, with the head retracted. X 60. 



3.") Organs on the head, apparently adapted for sensation, and possibly repre- 



4. j senting antennas. X 250. 



5. Portion of margin. X 60. 



6. Skin of dorsal surface. X 250. 



7. Part of the last segment. 



a. The large posterior seta. 



b. The spiracle. 



c. The trachea. 



d. A place where two of the lateral processes have been slightly sepa- 



rated from one another. 



8. Posterior end of body, seen from below, x 30. 



a. The tubercles of the posterior margin. 

 b b. The foot-like lobes. 



9. Insect in the second stage. X 30. 



