94 PATTEN AND REDENBAUGH. [Vol. XVI. 



(3) The Hind-Brain. page 

 Second to sixth thoracic ne«romeres; ganglia, cross-commissures, 



neural nerves with mandibular and ento-coxal branches, haemal 

 nerves with intestinal and cardiac branches 135 



(4) The Accessory Brain. 



Neural nerves, haemal nerves, with intestinal and cardiac branches 135 



Fusion of cardiac branches and connection with lateral sympathetic 



and pericardial nerves; the vagus region 136 



b. The Ventral Cord. 



Abdominal ganglia and their location 136 



Five branchial neuromeres ; neural nerves, haemal nerves with intes- 

 tinal and cardiac branches 137 



Two post-branchial neuromeres without neural nerves ; haemal nerves 



with intestinal and post-cardiac branches 137 



2. Peripheral Nervous System. 



a. Ne?-ves from the Fore-Brain. 

 (i) Olfactory Nerves. 



Median and lateral; Patten's description of them 137 



(2) Median Eye Nerves. 



Two described by Owen 138 



Origin and distribution 138 



Patten's description of the distal end of the median eye nerve 139 



(3) Lateral Eye Nerves. 



Origin, course, pigmental body, distribution, blood vessel 139 



Description of a Typical Neuromere. 

 (i) Abdominal N'euromere. 



A pair of ganglia and cross-commissures ; neural nerve ; haemal nerve 

 with double intestinal branch, cardiac branch communicating with 

 the lateral sympathetic and pericardial nerves, and integumentary 



branch 139 



(2) Cephalic or Cranial Neuromere. 



A pair of ganglia with cross-commissure ; neural nerve with mandibu- 

 lar, ento-coxal, and pedal branches ; haemal nerve with intestinal 

 cardiac and integumentary branches 141 



b. Nerves from the Mid-Brain. 

 (i) Neural Nerves. 



Origin ; external and internal pedal nerves and their distribution to 

 chelicerae 142 



(2) Haemal Nerves or Lateral Nerves. 



Origin ; fusion with second haemal nerve ; distribution upon neural side 



of cephalothorax and abdomen 143 



Problematical sense organ opposite flabellum 143 



Comparison with other haemal nerves I44 



Mentioned by Owen, Viallanes, and Patten 144 



(3) 77^1? Stomodaeal Nerves. 



Origin and distribution to oesophagus, proventriculus, and pyloric 

 valve 144 



Ganglion upon proventriculus and cardiac branches described by Milne- 

 Edwards 144 



