l. The bristle on the penultimate segment of the legs arises from near the middle; no suture between the cephalothorax and abdomen. The species, some of which occur in the United States, feed on dried fruit, etc. Carpoglyphus Robin.
ll. The bristle on the penultimate segment of the legs arise from near the tip; a suture between cephalothorax and abdomen.
m. Cephalothorax with four distinct and long bristles in a transverse row; tarsi I and II about twice as long as the preceding segment ([fig. 150 f]). Tyroglyphus Latr.
n. Some bristles on tarsi I and II near middle, distinctly spine-like; the sense hair about its length from the base of the segment. Several species in the United States belong to this group.
nn. No spine-like bristles near the middle of the tarsi; sense hair not its length from the base of the segment.
o. Of the terminal abdominal bristles, only two are about as long as the abdomen; leg I of the male greatly thickened and with a spine at apex of the femur below. T. farinæ.
oo. Of the terminal abdominal bristles at least six or more are very long, nearly as long as the body.
p. Bristles of the body distinctly plumose or pectinate; tarsi very long. T. longior.
pp. Bristles of the body not pectinate.
q. In mills, stored foods, grains, etc. Third and fourth joints of hind legs scarcely twice as long as broad; abdominal bristles not unusually long; legs I and II of the male not unusually stout. T. americanus.