568 



MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



PI.ATK LTII. 



FIG. 193. Part of transverse section through an embryo of Alpheus saulcyi, which is nearly ready 

 to hatch, .showing the third left branchia covered by the brauchiostegite. x289. 



FIG. 194. Part of sagittal section of eyestalk of a slightly younger embryo. x289. 



FIG. 195. Part of transverse section, showing branchia, of the third larva of Alftheun saulcyi ( twenty- 

 four hours old). x289. 



FIG. 196. Nearly mediau longitudinal section of first larva of same. The anterior lobes of the 

 midgut (ig l ) still contain unabsorbed yolk. Compare PL xxi, Fig. 1. x58. 



FIG. 1H7. Part of transverse section, showing the papilla, which bears the median eye in the first 

 larva of same, x 28JI. 



FIG. 198. Transverse section of first larva, cutting the lateral liber balls of the brain, the. anterior 

 lobes of the midgut, and the green gland. x289. 



FIG. 11M). Part of transverse section through an advanced embryo of Alphevs savlcyi, parasitized 

 by a fungus, most of the cells of which are encysted. From brown sponge, Abaco, 

 Bahama Islands, v, Appendix II. xl'Sii. 



REFERENCE LETTERS. 



nl>., abdomen. 



Ab. n, sixth abdominal nppcnda<v. 



iic/i., accessory ]>ignient cells. 



ay., green gland. 



</. ., end sac (?) of gland. 



(is. ., superior abdominal aorta. 



by., branchiostegite. 



b. s., B. S., blood space. 



br. 3 , branchia of third left ambulatory limb. 



i-i:., crystalline cone cells. 



HI., corueagen. 



ril., lens. 



en., crystalline cone. 



cs., f.'~ : , cysts of parasite. 



CD.'', smaller, naked cells of parasite. 



(/.' '-'", segmental ganglia. 



(//'., liber-mass of second :mtenn;i-. 



iima., anterior gastric mnsele. 



//., heart. 



Ilil., hvpodermis. 



HIJ., hiiidgnt. 



Lb., hi In ii in 



J. c., loiigitiidiual commissure. 



/</., midgut. 



nig. 1 , anterior lobes of midgut. 



my."*, lateral lobes of midgnt. 



mg. 3 , posterior lobes of midgut. 



mo., month. 



ma,, masticatory stomach. 



inn. <-.., extensor muscles of abdomen: 



/./., flexor muscles of abdomen. 



ii. c., neural cord. 



oc., ocellus. 



or., oesophagus. 



f>. <!., o.y., optic ganglion. 



of., optic enlargement of brain. 



op., ophthalmic artery. 



j)s., pericardial sinus. 



pr., periueuriuni. 



R,, rostrum. 



Bet., retiua. 



rtl., nucleus of proximal retiuular cell. 



soy., brain. 



NJI.. parasitic growth. 



Sl.x., sternal blood sinus. 



T., telson. 



y., yolk. 



