Oehlert (1896) gave an excellent summary in French of the work of Beecher and Walcott on _Triarthrus_, with reproductions of many of their figures. Valiant (1901) in a non-technical article described his long search for trilobites with antennas. The discovery of the wonderful pyritized trilobites at Cleveland's Glen near Rome was not the result of a lucky accident, but the culmination of eight years of labor in a locality especially selected on account of the fineness of grain of the shale. [Illustration: Fig. 10.--_Triarthrus becki_ Green. A new restoration, modified from Professor Beecher's, to incorporate the results of his later work. The inner ends of the endobases are probably too far apart, as it was not discovered until after the drawing had been made that the appendifers projected within the dorsal furrows. Drawn by Doctor Elvira Wood. × about 3.8.] After 1896, Professor Beecher turned his attention largely to the problem of the classification of trilobites, and while he continued the arduous task of cleaning the matrix from specimens of _Triarthrus_ and _Cryptolithus_ he did not again publish upon the subject of appendages until forced to do so by the doubts cast by Jaekel (1901) upon the validity of his earlier conclusions. Because of certain structures which he thought he had interpreted correctly from a poorly preserved specimen of _Ptychoparia_, Jaekel came to the conclusion that Beecher's material was not well preserved. Professor Beecher would have taken much more kindly to aspersions upon his opinions than to any slight upon his beloved trilobites, and his article on the "Ventral Integument of Trilobites" of 1902 was designed not only as an answer to Jaekel, but also to show by means of photographs the unusually perfect state of preservation of the specimens of _Triarthrus_. This article, like so many describing the appendages of trilobites, beginning with Matthew's, was published in two places (Beecher 1902). Most of Beecher's papers, except the last one, were reprinted in the volume entitled "Studies in Evolution," published by Charles Scribner's Sons at the time of the Yale Bicentennial in 1901. The part pertaining particularly to _Triarthrus_ is on pages 197 to 219. Moberg (1907), in connection with a specimen of _Eurycare angustatum_ which he thought preserved some appendages, described and illustrated some of the appendages of _Triarthrus_. The most recent discussion of _Triarthrus_, with some new figures, is by Walcott (1918, p. 135, pls. 29, 30). He gives a summary of Beecher's work with numerous quotations. The principal original contribution is a discussion of the form and shape of the appendages before they were flattened out in the shale. He found also what he thought might possibly be the remains of epipodites on three specimens, one of which he illustrated with a photograph. I have seen nothing which could be interpreted as such an organ in the many specimens I have studied.