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70 NOTES ON 
CHAPTER X. 
THE ROUND LYNCEUS. 
Lynceus sphericus.— Miller. 
Monoculus minutus.—Linné. 
This creature is generally known by the name 
of the small Monoculus, though a very slight 
examination will convince us of the impropriety 
of this appellation, as its two eyes may be very 
distinctly seen. Miiller, from whom I borrow 
the name at the head of this chapter, has with 
more propriety classed it with his Binoculi. 
The shells of the Monoculi, as well as that of 
the present subject, are beautifully marked with 
reticulations of various forms, and present under 
the microscope diversities in structure highly 
worthy of investigation. The mosaic appear- 
ance of the shell of this Lynceus closely resem- 
bles the joints in masonry or brick-work. In 
the Monoculus vulgaris (Daphnia pulex, Miil.) 
the shell is covered with diamond-shaped reti- 
culations, while in other species it is divided 
into hexagons and other angular figures. 
