SMALLWOOD. — POLYCERELLA ZOOBOTRYON. 629 



somewhat beyond its anterior rim, where it is in contact with the 

 cornea. The pigment (jyig.) is very dense, consisting of numerous 

 small granules which appear to be located in the retinal cells. At 

 least I was not able to make out the existence of more than this one 

 layer of cells, though it is possible that maceration preparations would 

 have disclosed the presence of other (pigment) cells. The pigment 

 layer is thickest at the bottom of the cup, becoming gradually thinner 

 toward the cup's lips. The cornea and retina apparently consist of 

 only a single layer of cells arranged radially ; the cells of the cornea 

 {cm.) are much flattened, and stain faintly. The layer contains but 

 few nuclei in front of the lens. The cells become cubical in the region 

 of the retina {rtn.\ the center of which is occupied by a single large 

 cell with a conspicuous nucleus. Inasmuch as the eyes were not 

 especially fixed and stained for histological study, it was impossible to 

 analyse further the retina or to determine the course of the fibrillae 

 after they enter the retina. Strands of fibrillae were traced from the 

 cerebral into the optic ganglion and thence to the proximal border of 

 the retina. 



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Bergh, R. 



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Pohl, H. 



:05. Uber den feineren Bau des Genitalsystems von Polycera quadri- 

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Smallwood, W. M. 



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