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PATTEN AND REDENBAUGH. 



[Vol. XVI. 



the ensheathing artery be removed, the three nerves may be 

 seen arising from a common trunk, which may be traced to the 

 margin of the nerve collar. Each of the three mandibular 

 branches bears at its proximal end a small ganglionic swelling. 

 The first branch gives off a small nerve to the inner mandible 



Fig. II. — Diagram showing muscles and distribution of nerves in the third leg of Limulus, from the 

 anterior side (K natural size). 



i-cox., coxopodite, or first joint ; 3-bas., basipodite, or second joint; S-isc, ischiopodite, or 



third joint ; 4- \ '^'^''•' fused carpopodite and meropodite, or fourth joint ; 3-pro., propodite, or 



fifth joint ; b-dac., dactylopodite, or sixth joint ; apo., apodeme ; h.c. , haemal side of carapace ; 

 e«^o., endocranium ; //^., heart; /«/., intestine ; z'.waw., internal mandible ; w., mouth; man., 

 mandible ; /., pericardium ; f.s., pericardial sinus. 



Muscles : ja and h, plastro-coxal muscles inserted upon anterior side of entocoxite ; 

 jcand d, tergo-coxal muscles inserted upon anterior side of entocoxite; <?.2-6, extensors of 

 second to sixth joints ; /.2-6, flexors of second to sixth joints ; y.m, flexor of inner mandible. 



Nerves: n.e.ti., anterior ento-coxal nerve; i5>-., brain ; e.p.n., external pedal nerve; h., 

 haemal branch of integumentary nerve; /;.«.3, haemal nerve; in.n.'i, integumentary branch ; 

 »./>.«., internal pedal nerve; w.c.w., median ento-coxal nerve; m.n., mandibular nerves; «., 

 neural branch of integumentary nerve ; n.n.^, neural nerve \ p.e.n., posterior ento-coxal nerve. 



