MEMOIRS OF THE NATIOISIAL ACADEMY OF 



Platf, XLIX. 

 (Stages X aiul XI [.) 



• 



Figs. 169-173. Parts of serial transverse sections through the embryo of Alpheus saulcyi in Stage 

 X. Ill Fig. 173 the reproductive organ B. O. is cut. xlliO, (Fig. 173, x23'l.) 



Fig. 174. Horizontal section through nervous system of the tirst larva, on a level with the (Bso[)ha- 

 geal comtnissiuos. x234. 



Figs. 175, 176. Transverse sections through the neural cord of the first larva. In Fig. 176 the 

 transverse commissure of the ganglia of the tenth segment is cut and in Fig. 175 

 the short longitudinal commissures between the tenth and eleventh segments are 

 sectioned, x 129. 



REFERENCE LETTERS. 



.1. /, firstr antenu.a. 

 J. //, second antenna. 

 .tb., abdomen. 

 ag., antennal glaud. 

 B.C., blood oorpiiscleB. 

 />'. .S'., blood Hiiins. 

 Hi:, braiiehia. 

 cp., carapace. 

 End., eiidoderm. 

 /(/., forejrut. 

 g. c, ganglion cell. 

 Hd., liypodermiH. 

 //(/., hiudgut. 



/./., lateral iibor-iiiaHx of. Iiraiu. 

 Md., base of mandible. 

 Mes., mesoderm. 

 Mg., meseiiteron. 

 Mil., mnscle. 



Mil. e., extensor muscles of abdomen. 

 Mil./., flexor muscles of abdomen. 

 .Mx., base of maxillic. . 

 Mxpd., base of maxillipeds. 

 II. c, neural cord. 

 ((/., optic fiber-mass of liiaiu. 

 o.g., o))tic ganglion. 

 Pi., perineurium. 

 A". O., reproductive organ. 

 eoy., brain. 



/. c. , transverse commissure. 

 ^. c, wandering cells. 



