Volume VII (plate V A), a large fragment representing the greater part

of the thorax and the pygidium, and according to the restoration there given the original length of the animal must have been well nigh 15 inches. The later and common Hamilton species, _H. DeKayi_, attained no extravagant size though frequently large, e. g. the enrolled individual figured on plate IV (_op. cit._), the largest entire specimen reported, which is about 9 inches in length; some large fragments indicate that the animal was sometimes as long as 11 inches.

The size attained by some of the Devonian species of DALMANITES and their immediate predecessors was marvelous. The pygidium of _D. micrurus_ figured in the Palæontology of New York, Volume III, page 359 (there given as _D. pleuroptyx_), indicates an individual at least 11 inches in length, and there is reason to believe that the Lower Helderberg species, _D. nasutus_ and _D. tridens_, attained a size fully as great. Most remarkable however is the great pygidium of _D. myrmecophorus_ of the Corniferous limestone, figured upon plate XV of