[duporte] LARVA OF SPHIDA OBLIQUA WALKER 233 



The nerve continues forward and near the base of the maxilla gives 

 off branch d which runs laterally and bifurcates, branch 1 runs to the 

 base of the maxilla where it branches profusely, innervating the 

 integument; branch 2 curves backward, receives nerve r of the lateral 

 sympathetic system, and then divides into two nerves which innervate 

 maxillary muscles. The maxillary nerve, after giving off branch d 

 enters the maxilla and gives off a large number of branches which go to 

 the muscles and sense organs. 



The Labial Nerve (fig. 4, Lb.) originates near the middle of the 

 anterior ventral surface of the ganglion and somewhat behind the 

 origin of the maxillary nerves. At a short distance from its origin it 

 sends out two branches; the proximal one a goes to the depres- 

 sor muscles of the labium; the second goes to the integument 

 where it divides into several branches. Branch c is quite stout and 

 runs forward, parallel and very close to the main nerve. It sends 

 nerves 1, 2 and 4 inward to the silk glands; nerve 3 goes to Fillipi's 

 glands, which are situated a short distance behind the union of the 

 two silk glands. After giving off branch 3, nerve c continues forward 

 for a short distance and then divides into two nerves, m and n. Near 

 the point of division, nerve n sends a minute nerve x across con- 

 necting with the corresponding nerve of the other side. This cross- 

 nerve passes above the silk glands and lies immediately behind their 

 point of union. Nerves m and n terminate in the muscles of the 

 labium. 



The fourth branch d of the labial nerve originates at a short 

 distance in front of the origin of c and runs forward to the integument 

 where it innervates a seta on the under side of the labium. Continu- 

 ing forward, the two labial nerves are conneected by a small cross- 

 nerve y. This nerve passes on the ventral side of the silk glands and 

 in front of the point where the two glands enter the common duct. 

 Two branches, 5 and 6, are given off from the cross-nerve near its 

 origin on either side and run back innervating labial muscles. From 

 the middle of the cross-nerve a single unpaired nerve, 7 , is given off, 

 and this runs directly to the ventral integument. 



The farther branches of the labial nerve in the anterior portion 

 of the labium are, — e and /, which go to the muscles of the spinneret, 

 g, which goes to the integument at the base of the palpus, and h 

 which has been traced to the base of the palpus, and which probably 

 innervates this organ. 



The Ventral Nerve. (Fig. 4, L.) The ventral nerve of the 

 suboesophageal ganglion arises from the lateral border of the ganglion 

 and runs outward and slightly backward toward the base of the head. 

 About 2 mm. from its origin it divides into two branches a and b. 



