EXPLANATION OF SYMBOLS AND LETTERS. 



145 



Pt, sensory pit. 



Ptr, peritreme, spiracle-bearing sclerite. 



Pvent, proventriculus. 



Pvent Vlv, proventricular tube or valve in ventriculus. 



Qd, quadrate plate of sting. 



R, radius, third vein of generalized wing. lii-Ro, first to fifth branches 

 of radius, i?,,, radial sector. 



RAp, apodeme of flexor muscle. 



Rd, posterior extension or reduplication of any tergal or sternal plate 

 overlapping plate following it. 



Red, rectum, the large intestine of insects. 



RGl, rectal glands. 



r-m, radio-medial cross-vein. 



RMcl, flexor nuiscle of mandible or wing. 



IRMcl, dorsal retractor muscle of ligula. 



2RMcl, ventral retractor muscle of ligula. 



Rs, radial sector, or second branch of radius at fii'st forking. 



8, sternum. 



SalD, salivary duct. 



SalDO, external opening of salivary duct. 



Sc, subcosta, second vein of generalized wing. 



Scl, scutellum. 



Sep, scape. 



Set, scutum. 



Sga, subgalea. 



SJi, sheath of sting, equivalent to the second gonapophyses (20) or 

 middle pair on ninth abdominal segment. 



8hA, basal arm of sheath of sting. 



ShB, bulb of sheath of sting or ovipositor. 



ShS, shaft of sheath of sting. 



SInt, small intestine. 



SI, sternellum. 



SUii, superlingua, embryonic lateral lobes of hypopharynx, true append- 

 ages of fifth head segment. 



Smt, submentum. 



SceGng, suboesophageal ganglion. 



Sp, spiracle. 



Spm, spermatheca. 



SpmOl, spernia thecal gland. 



St, stipes. 



StgNv, stoma toga stric nerve. 



Stn, sting. 



StnPlp, palpuslike appendages of the sting, equivalent to the third gona- 

 pophyses (30r) or the outer pair on ninth abdominal segment. 



T, tergum. 



IT, first abdominal tergum, the propodeum, incorporated into thorax. 



IIT, second abdominal tergum. 



Tar, tarsus. 



Tb, tibia. 



Ten, large tentorial arms of head, the mesocephalic pillars. 



ten, slender tentorial arch over foramen magnum, 



Tes, testes. 



Tg, tegula. 



22181— No. 18—10 10 



