No. I.] STUDIES ON LIMULUS. 95 



(4) Rostral Nerves. page 



Two found by Milne-Edwards; three by Patten; origin from anterior 



commissure and distribution to the rostrum 14c 



C. Nerves from the Hind-Brain. 



Second to sixth neuromeres _ 14c 



(i) Neural Nerves. 



General distribution ; division into mandibular, ento-coxal, and pedal 



branches . 



MS 



(a) Mandibular Branches. 



Distribution to mandibles of third pair of appendages 145 



Comparison of these with branches in second, fourth, fifth, and sixth 

 appendages 147 



(b) Ento-coxal Branches. 



Anterior ento-coxal nerve ; origin and distribution to anterior coxa! 



muscles and anterior sensory knob 147 



Posterior ento-coxal nerve ; distribution to posterior coxal muscles 



and posterior sensory knob 140 



Median ento-coxal nerve; distribution to median sensory knob 149 



Absence of median one in second appendage 149 



In sixth appendage median ento-coxal nerve becomes flabellar nerve 1 50 



(c) Pedal Branches. 



External and internal pedal nerves ; distribution to distal joints 



of appendage i^o 



Modifications in sixth leg • icq 



(2) Haemal Nerves. 



General description of haemal nerves ; division into intestinal, cardiac, 

 and integumentary branches i cq 



(a) Intestinal Branches. 



Origin of one in sixth neuromere and passage through foramen in en- 



docranium to longitudinal abdominal muscles and intestine 151 



Intestinal nerve in second neuromere 151 



(b) Cardiac Branches. 



Origin, course, and distribution to inter-tergal muscle and haemal 

 epidermis i ci 



Absence in third, fourth, and fifth neuromeres ; doubtful cardiac 

 branch in fifth i c^ 



(c) Integumentary Branches. 



Branches to the neural and to the haemal surface ic-j 



Relations of the haemal nerves to each other and to the median eye 



and lateral nerve IC4 



d. Nerves from the Accessory Brain. 



General remarks i C4 



(i) Neural Nerves. 



(a) Chilarial Nerve. 



Origin, passage through occipital ring, and distribution to chilarium 1 54 



(b) Opercular Nerve. 



Origin and distribution to operculum ; external, median, and internal 

 opercular nerves 154 



