1918.] 



NATURAL SCIENCES OF PHILADELPHIA. 



77 



rectal trachea, Idrti, respectively. Each of these runs mesad and 

 caudad and enters the dorsal longitudinal fold of the alimentary 

 canal (Fig. 1). Here these tracheae divide and subdivide, but no 

 anastomosis between the tracheoles of the right dorsal rectal trachea 

 and the left dorsal rectal trachea was found. 



cm 



dv 



Idrti 



llpa 

 Idt 

 drf 



Urti 

 llrj 



cf 



ts 

 vd 

 rdrt 



rdt 



rlpa 



cm 



rlrti 



rlrf 



n 



mt 



mvpa 



Fig. 1. Transverse section of abdomen of larva of ArQia moesta putrida 

 cf near the middle of the 7th segment (TS. 52, row 4, slide 3) seen from its 

 posterior face. Cuticle and hypodermis removed before embedding. Photo- 

 graphed by Mr. H. A. Walters, using Leitz ocular 4, objective 3. Enlaro-ed 

 117 diameter.?. 



cf, connective tissue and fat. 



cm, circular muscles of gut wall. 



drf, dorsal rectal fold. 



dv, dorsal vessel. 



Idrti, left dorsal rectal trachea. 



Idt, left dorsal trachea. 



llpa, left lateral pigmented area. 



llrf, left lateral rectal fold. 



llrti, left lateral rectal trachea. 



mt, Malpighian tubule. 



7nvpa, mid-ventral pigmented area. 



n, nerve. 



r, rectum. 



rdrt, fight dorsal rectal trachea. 



rdt, right dorsal trachea. 



rlpa, right lateral pigmented area. 



rlrf, right lateral rectal fold. 



rlrii, right lateral rectal trachea. 



ts, testis. 



vd, vas deferens. 



