420 R. S. Lull — Life of the Connecticut Trias. 



down the six or seven thousand feet of the lower series of 

 granitic, coarse sandstones, we have but little record of the 

 action ; but two entrances are recorded, one of which is at 

 JSTew Haven when the heavily armored Stegomus arcuatus 

 appears, whose habits we can scarcely conjecture, as the burial 

 of its body in river sediment means little. The second scene 

 at Simsbury is more intelligible because, while part of a 

 shoulder blade only is preserved, it is from the representative 

 of a genus Rhytidodon which is almost completely known, 

 hence we are justified in applying the old Cuvierian principle 

 and reconstructing, not only a long-snouted, fish-eating animal 

 from a single bone, but its fish-supporting, aquatic environ- 

 ment as a stage setting as well. 



This act closed with the first lava outpouring, the so-called 

 anterior trap, which was followed immediately by the second 

 act, that of the anterior shales, interesting in being ushered in 

 by the first fish- and plant-bearing black shale deposit, followed 

 in the region round about Mount Holyoke and Mount Tom by 

 the first recorded appearance of dinosaurs in the Connecticut 

 valley. Of these Eubrontes giganteus, one of the very largest, 

 was among the first, possibly representing a form like the 

 larger genera well known from their bones in the Old World. 

 Others were the larger species of Anchisauripus, indicating 

 the presence of Ammosaurus-like dinosaurs as well. This 

 second act, with but a thousand or more feet to its credit, was 

 the briefest of all, and the interact following, as befits the 

 middle of the drama, was the most stupendous with the accu- 

 mulation of the 500 feet of lava which constitutes the main 

 trap sheet. 



Act III, during which the posterior shales were laid down, 

 is still more prolific of animate records, for the known foot- 

 prints not only increase in number, but here for the first time 

 we find those of Anommjpus giving the earliest reasonably sure 

 record of the advent of plant-feeding dinosaurs, while that of 

 Grallator cursorius shows that accompanying their larger, 

 fiercer brethren were the lighter, more agile dinosaurs of comp- 

 sognathoid type. This act closed with another scene, during 

 which the plant- and fish-bearing black shales could be accu- 

 mulated. The relative duration of these posterior shales was 

 somewhat greater than that of the anterior deposition, but was 

 followed by the smallest of all the lava outpourings, that of 

 the posterior trap. 



It is only in the final act that the profusion of the cast be- 

 comes evident, for at various levels within the 3,500 feet 

 of its accumulations, but notably toward its close, at Port- 

 land, around South Hadley, and within and about Turners 

 Falls, are recorded by far the great majority of the known 



