NO. 3 



INSECT HEAD — SNODGRASS 



155 



P, thoracic depressor muscle of tro- 

 chanter. 



PcR, posterior cranial ridge. 



Pdc, pedicel. 



Pdp, pedipalp. 



Pge, postgena. 



Pgl, paraglossa. 



Ph, phragma. 



Phy, pharynx. 



PLGng, posterior lateral stomodeal 

 ganglion. 



Pip, palpus 



Pnt, postantennal appendage. 



Poc, postocciput, postoccipital rim of 

 foramen magnum. 



PoR, postoccipital ridge. 



pos, postoccipital suture. 



Pp, " pleuropodium," specialized ap- 

 pendage of first abdominal seg- 

 ment. 



Ppd, parapodium. 



Ppt, periproct. 



PrC, preoral cavity. 



Pre, protocephalon. 



Priit, preantennal appendage. 



Proc, proctodeum. 



Prst, peristomium. 



Prtp, protopodite. 



Pst, prostomium. 



PT, posterior arm of tentorium. 



pt, posterior tentorial pit. 



Ptar, praetarsus. 



Q, depressor muscle of palpus, or of 



trochanter. 

 Rd, posterior fold of tergum. 



rh, retractor of hypopharynx. 

 RNz>, recurrent nerve. 



SA, sternal apophysis. 

 Sep, scape. 

 Sex, subcoxa. 

 Ser, serosa. 

 Set, seta, setae. 

 SgR, subgenal ridge. 

 sgs, subgenal suture. 

 SID, salivary duct, silk gland duct. 

 SJO, opening of salivary duct. 

 Sint, submentum. 



SeoGng, suboesophageal ganglion. 

 Sp, spiracle, iSp, first thoracic spir- 

 acle. 

 Spn, spina. 

 Spt, spinneret. 

 St, stipes. 

 Stoni, stomodeum. 



T, tergum. 



depressor muscle of tibia. 

 Tar, tarsus. 

 Tb, tibia. 

 Th, thorax. 

 77, tentacle. 

 Tip, telopodite. 

 Tnt, tentorium. 

 Tor, torma. 

 Tr, trochanter. 



J\ fifth head segment. 



vap, ventral apodemal plate of postoc- 

 cipital ridge. 



VI, sixth head segment. 



VMcI, ventral longitudinal body mus- 

 cle. 



VNC, ventral nerve cord. 



VNv, ventral longitudinal nerve. 



Vx, vertex. 



REFERENCES 



Attems, C. (1926). Myriapoda. Krumbach's Handbneh dcr Zoologie, 4. Ber- 

 lin, Leipzig. 



Balfour, F. M. (1880). Notes on the development oT the Araneina. Quart. 

 Jonrn. Micr. Set., n. s., 20: 1-23, pis. 19-21. 



(1883). The anatomy and development of Peripatus capensis. Quart. 



Journ. Micr. Sci., n. s., 23:213-259, pis. 13-20. 



Basch, S. (1865). Untersuchungen iiber das Skelet und die Muskcln des 

 Kopfes von Termes flavipes (Kollar). Zeit. luiss. Zool, 15:56-75, pl- 5- 



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