572 MEMOIKS OF THE NATIONAL ACADEMY OF SCIENCES. 



Plate LV. 



(Stage XII.) 



Figs. 212-22.'?. Transverse serial sections of the first larva of Alpheus saulcyi from the same indi- 

 vidual iis Figs. 209-211, excepting Figs. 222, 223. x 73. 



REFERENCE LETTERS. 



A. II, second anteuua. 



ad. m., adductor of mandible. 



ag., green gland. 



o/., antennular fiber-mass of brain. 



ao., ear. 



a.op., ophthalmic artery. 



Bg., brancUiostegite. 



B.gl., glaud-like body. 



B. S,, blood sinus. 

 /;/., foregut. 



/«., liber-maes continued into ffisophageal commissure. 



gf., antennal fil)er-mass. 



(/«., lateral pouch of masticatory stom.ach. 



Li., labrum. 



//., lateral fiber-mass of brain. 



Md., mandible. 



Mg., midgut. 



Mg'., anterior lobe of midgut. 



Mg^., lateral lobe of midgut. 



Mp., septum between anterior lobes of midgut. 



M. S., masticatory stomach. 



MU., metastoma. ^ 



Mx. I, first maxilla. 



Mjrpd. I, first maxilliped. 



n.ag., antennal nerve. 



M. aw., autennular nerve. 



00., ocm., o\sophageal commissure. 



of., anterior tilier-mass and transverse commissure of brain. 



p.. F., pyloric valve of masticatory stomach. 



s(. «., sternal sinus. 



