EXPLANATION OF SYMBOLS AND LETTERS. 147 



X, thoracic plate lyiiif? laterad of anterior part of steriiiuu, often 



regarded as a part of prestermmi. 



y, accessory sclerite of fourth axillary i'lAx) of front wing, affording 



insertion for slender muscle (fig. 2S, cc) attached below to 

 common apodeme of mesosteruum and meta sternum. 



z, coxal condyles of mesothoracic and metalhoracic sterna, probably 



really the coxal condyles of trochantins (fig. 4, TnC) fused en- 

 tirely with the sterna and episterna in each segment. 



aa, muscle arising from inner wall of mesothoracic pleurum and in- 



serted ui)on outer end of corresponding scutellum, probably ac- 

 cessory in function to the great vertical muscles (fig, 27, VMcl) 

 between the mesothoracic sternum and scutum. 



&6, coxo-axillary muscle, extending from upper end of coxa to third 



parapterum {3P). 



cc, muscle inserted upon accessory sclerite (//) of fourth axillary 



i'lAx) from common entosternum of mesothorax and meta- 

 thorax. 



(hi, notch of antenna cleaner on first tarsal joint (ITar) of front leg. 



ee, spine of antenna cleaner situated on distal end of tibia (Tb). 



ff, so-called " wax shears " or " wax pincers." 



f/ff, ti'ansverse chitinous band of empodium (Emp),- which compresses 



its two lobes when not in use and spread out by muscular effort. 



/'//, dorsal plate supporting empodium. 



a, ventral ])late supporting empodium. 



jj, dorsal groove of lancet interlocking with ventral ridge of sheath of 



sting. 



kk, sting chamber within end of seventh abdominal segment, lodging 



sting whose accessory plates are derived from eighth and ninth 

 segments. 



U, reservoir of thoracic salivary gland. 



invi, receptacular chitinous pouches on ventral side of pharyngeal plate 



is) receiving ducts of large lateral pharyngeal glands of head 

 (IGl). 



nn, " stomach-mouth " at summit of proventricular projection within 



honey stomach (//S). 



00, pores on lancets (fig. 40 E) and shaft of sting sheath (F) open- 



ing to exterior from prolongation of body-cavity (6c) contained 

 In each. 



pt), gelatinous layer secreted upon inner surface of ventricular epi- 



thelium. 



qq, food contents of alimentary canal. 



rr, cells of ventricular epithelium apparently forming the internal 



gelatinous layer. 



ss, cartilaginous mass on inner surface of dorsal wall of bulb of 



penis (fig. 5G E, PcnB). 



tt, dorsal plates of bulb of penis. 



KU, fimbriated dorsal lobes of penis at base of bulb. 



vv, ventral scalariform row of plates on tube of penis. 



ivw, dorsal basal plates of penis. 



XX, ventral basal i)lates of penis. 



yy, basal i)ouch of penis. 



sz, copulatory sacs of penis. 



