REFERENCE LETTERS, PLATES VIII TO XIII. 



Lettering used more than once is given here. The remainder 



will be found in the descriptions of the plates. 



a. a. Anterior arch. 



a. mu. Anterior and median set of muscles. 

 ap. Apodeme of the labrum. 



axp. Axial apophysis. 



b. Bulb. 



b. c. Buccal cavity. 



cl. Clypeus. 



d.ph. Dilator muscle of the pharynx. 



d. s. Discal sclerite. 



ex. h. Extensor muscle of the haustellum. 



f. Fork of the mentum. 



f. ch. Food channel, formed by the labrum-epipharynx and 



the hypopharynx. 



fl. Fulcrum, 



fu. Furca. 



hy. Hypopharynx. 



k. Keel of the labial gutter. 



1. ep. Labrum-epipharynx. 



1. gl. Labial gutter. 



1. r. Lateral rod of the labial gutter. 



Ib. r. Labellar rod. 



Ibl. Labellum. 



mb. Membrane, 



mt. Mentum. 



oes. CEsophagus. 



p. Palp, 



p. b. Petiolated blade, 



p. c. Posterior cornu of fulcrum. 



p. m. Pseudotracheal membrane, 



p. mu. Posterior and lateral set of muscles, 



p. s. Pseudotrachea. 



ph. Pharynx. 



r. h. Retractor muscle of the haustellum. 



r. h. p. Posterior retractor of the haustellum. 



r. r. Retractor of the rostrum, 



rd. h. Rod-like hairs, 



si. d. Salivary duct, 



si. v. Salivary valve, 



t. Prestomal tooth, 



t. mu. Transverse set of muscles, 



tr. Trachea. 



