with the common ascarid of man, Ascaris lumbricoides, though yet 
discussed in many texts as A. suilla. The eggs (Fig. 19) of this worm 
are from 56.5 to 87.5 microns long by 46.5 to 57.5 microns wide; they 
Fig. 20. Arduenna strongylina. Egg. From Foster, 1912. 
are elliptical, with thick, transparent shells surrounded by a thick layer 
of albumen which is irregularly mammilated and yellow, and are not 
segmented when deposited. 
There are two species of spirurid worms, Arduenna strongylina 
and Physocephalus sexalatus, which are not uncommon in ,the stomach 
28 
