color, head tinged with, brown, and black mouth parts, with the abdomen strongly curved. The adult is a small, cylindrical, brown beetle from two to three millimetres in length, with head bent down and wing covers marked with fine punctate striæ.
Professor Poey made extensive observations of an insect in Cuba which had destroyed about four thousand volumes. He called it Anobium bibliothecarum, and Schwartz thinks the injury reported by Herminier from Guadeloupe should be attributed to the same species. Anobium striatum and pertinax have long been known to injure books by their "gnawing and burrowing," not only in and through the bindings, but also entirely through the volumes. Nicobium hirtum, a native of southern Europe, where its larvæ have been found doing like injury, is only locally abundant, and for this reason has never been considered a serious library pest. Schwartz says, "In one way or another the insect has found its way to North America, but has always been regarded as a great rarity with us."
The Ptinus group embraces Ptinus fur, Ptinus mollis, Ptinus brunneus, and Ptilinus pectinicornis, called by Leunis "Bücherbohrer" According to Butler, a peculiarity of this genius—that of dissimilarity of shape between the sexes—is well illustrated by the P. fur, the male being almost cylindrical, the female inflated or rounded at the sides; so much variation that they might be taken for two different insects. Ptinus brunneus, although similar to P. fur, is distinguished from it by being wholly of a light-brown color and destitute of whitish bands on the wing covers. Some writers speak of this species as the "book beetle," while Sitodrepa is spoken of as the "spice beetle." Dr. Henry Shimer makes the following statement regarding their method of boring: "They usually operate in leather-bound or half-bound volumes by boring galleries along in the leather.… They usually bore along quite under the surface of the leather, cutting it almost through; occasionally a small round hole penetrates through the leather to the outer surface."
One of the most famous cases on record of insects boring through books is that reported by M. Peignot, in which he states that twenty-seven folio volumes were pierced through in so straight a line that a cord might be passed through them and all the volumes raised by means of it. Different writers give the credit of this feat to different members of this group, so that the most that can be said is that it was the work of some member of the Ptinidæ.
In the family Scolytidæ only one species belongs to the book ravagers. It is known as Hypothemus eruditus, and was described by Westwood in 1836 as "pitchy black, the head of the same color, entirely concealed from above by the front thorax." It is very minute in size, being about one twentieth of an inch in length. So
