THE FIRST MAXILLA 



33 



but very diverse views have been advanced to explain the 

 morphology of the basal region of the maxilla. In recent years 

 three interpretations have been put forward, viz., those of Borner 

 (1909, 1921), Crampton (1922) and Snodgrass (1928). These are 

 briefly summarised below. 



1 . According to Borner the cardo of the maxilla is the counter- 

 part of the subcoxa. and the stipes the homologue of the coxa, 



Fig. 19. Maxilla of Periplaneta. A, left maxilla, posterior (ventral) 

 surface. B, internal surface of cardo. C, right maxilla, anterior 

 (dorsal) view, showing muscles. Cd, cardo ; e, articulation of 

 cardo with cranium ; fga, flexor of galea ; flee, cranial flexor of 

 lacinia ; flcs, stipital flexor of lacinia ; Ga, galea ; /, promotor 

 of cardo ; KLed, adductor of cardo ; KLst, adductor of stipes ; 

 Le, lacinia ; O, levator of palpus ; Pip, palpus ; Q, depressor 

 of palpus ; q, sub-marginal suture (and internal ridge) near 

 inner margin of stipes ; r, internal ridge of cardo ; St, stipes ; 

 T, depressor of fourth segment of palpus ; V, depressor of 

 fifth segment of palpus. (After Snodgrass.) 



while the galea and lacinia are coxal endites. The palpifer is a 

 subdivision of that part of the stipes ^which bears the palpus and 

 galea ; it is, therefore, not a true segment. 



2. According to Crampton the cardo represents the coxa, and 

 the stipes is the homologue of the basis, while the galea and 

 lacinia are endites belonging respectively to the stipes and palpifer. 

 In this interpretation the palpifer is a true segment and represents 

 the first segment (or ischium) of the palpus. 



R.A. ENTOMOLOGY, 2 



