FoLSOM. — Mouth-Parta, Orchesella ciucta. 



PLATE 2. 



Fig. 9. Internal aspect of the labrura and clypeus, to show the epipharjnx. 



X 220. 

 Fig. 10. Dorsal aspect of the internal mouth-parts, in situ; the paraglossse are 



omitted. From dissections and potash preparations. X 116. 

 Fig. 11. Ventral aspect of the apex of the right mandible. X 440. 

 Fig. 12. Ventral aspect of the molar region of the right mandible. X 440. 

 Fig. 13. Dorsal aspect of the base of the left mandible, in situ; from a dissection. 



X 440. 

 Fig. 14. Dorsal aspect of the left mandible with its nmscles. Eeconstructed from 



serial sections, aided by dissections. X 116. 

 Fig. 15. Ventral aspect of the right mandible, to show certain muscles, and to 



supplement Fig. 14. From a dissection. X 116. 

 Fig. 16. Posterior aspect of a transverse section of the right mandible, cut near 



tlie anterior angle of the triangular orifice. X 220. 

 Fig. 17. Three ganglion cells from within a mandible. X 530. 



