These are the characteristic eggs of Taenia species. Note the thick outer striated shell and internal hooked onchosphere. They are among the smaller of the eggs found in human stool specimens, measuring just 30 to 35 micrometers in diameter. The eggs of the human-infecting intestinal Taenia, T. solium, T. saginata, and T. asiatica, are morphologically similar and cannot be differentiated by microscopy alone.