176 PATTEN AND REDENBAUGH. [Vol. XVI. 



represented by three branches arising from the haemal nerve 

 {h.n/'f) at some distance from the ganglion. One of these enters 

 the longitudinal abdominal muscles, the second anastomoses 

 with the twelfth intestinal nerve (i.n.'^), and the third enters the 

 intestine. 



The fifteenth intestinal nerve {i.nJ^) arises near the origin of 

 the fifteenth haemal nerve {h.n.'^) and passes posteriorly along the 

 surface of the intestine, giving off several branches to the intes- 

 tine, and then anastomoses with the sixteenth intestinal nerve 

 {i.n.'^). 



The sixteenth intestinal nerve {i.n.'^) arises from the caudal 

 branch of the sixteenth haemal nerve {Ji.n.'^) about midway 

 between the terminal abdominal ganglion and the anus, and 

 passes posteriorly a short distance to the side of the rectum, or 

 proctodaeum, where it divides into several branches. It was 

 at this point that Milne-Edwards found the "ganglion rectal." 

 One branch goes anteriorly to anastomose with the fifteenth 

 intestinal nerve {i.7i.'^), a second one goes posteriorly to the 

 levator ant [La.) and to the rectum, and the third goes to the 

 epidermis upon the haemal side of the base of the telson. 



In one methylen blue preparation the sixteenth pair of 

 intestinal nerves were joined together by a cross-branch upon 

 the neural side of the rectum. In some of the anterior neuro- 

 meres also a similar cross-branch has been found uniting the 

 intestinal nerves of the right and left sides of the body. This 

 seems to suggest that there is an elaborate network of nerves 

 in the tissues surrounding the intestine. As these nerves are 

 very delicate, it is difficult to trace them by dissection alone, 

 and many of them with their connections are necessarily 

 missed. 



The intestinal nerves (tji.^'^) of the sixth, seventh, and 

 eighth neuromeres are so complicated in their relations that it 

 is impossible to unravel them. The sixth (i.n.^) and seventh 

 (t.nJ) pass through foramina (/.^ and /J) in the endocranium 

 and lose themselves in the anterior portion of the mass of longi- 

 tudinal abdominal muscles. The eighth (z.n.^) goes directly 

 into these muscles near the posterior edge of the endocranium. 

 Sometimes each one of these nerves arises from the haemal nerve 



