162 John h. Gerould, The Develüpuieiit of Phascolosonia. 



lobes), to show the supraoesophageal ganglion and one of the pigment 

 spots with the optic nerve. 930: 1. 



Fig. 91. Obliquely frontal section of a larva of I'h. fjouldii of sixty- 

 five hours, showing the rudiment of a nephridium (which is shown again 

 in Fig. 92). 455 : 1. 



Fig. 92. Rudiment of nephridium. 1200 : 1. 



Fig. 93. Rudiment of a nephridium from a frontal section of a 

 larva of Ph. gouldii, eighty hours old (see Fig. 98). 1200: 1. 



Fig. 94. Rudiment of a nephridium from a frontal section of a larva 

 of Pit. gouldii, eighty-seven hours old. 1200 : 1. 



Fig. 95. Sagittal section of a larva of Ph. rubjare toward the end 

 of the period of metamorphosis (forty-seven hours). The yolk membrane 

 has been shed, but remnants of the prototroch cells still remain. The 

 proctodaeum has been established. Nerve fibrillae are evident in the 

 ventral nerve cord and circumoesophageal connectives. 455 : 1. 



Fig. 96. A combination of sections of the same larva as in Fig. 95, 

 to show the chief and accessory retractor muscles and the dorsal and 

 ventral neuromuscular organs. 455 : 1. 



Fig. 97. Parasagittal section of a larva of Pit. (jouldii of sixty-three 

 hours, showing a nephridium. 455 : 1. 



Fig. 98. Sagittal section of a larva of Ph. goiddii of eighty hours. 

 455 : 1. 



Fig. 99. Section of the body wall of a larva of Ph. rjoiddii, five 

 and a half days, showing an epidermal organ. 1000 : 1. 



Fig. 100. Transverse section of a larva of Ph. gouldii, of four and 

 a half days, showing a nephridium and the ventral nerve cord. 455 : 1. 



Lippert & Co. (G-. Pätz'sche Buchdr.), Naumburg a. S. 



