NATURE 



457 



THURSDAY, SEPTEMBER 16, i{ 



THE TOOTHED BIRDS OF KANSAS 

 Ocfontornithes : a Monograph of the Extinct Toothed 

 Birch of North America. By Prof. O. C. Marsh, Yale 

 College. Vol. I. of Memoirs of the Peabody Museum 

 of Yale College, New Haven, Conn., and Vol. VH. of 

 the Geological Exploration of the 40th Parallel. 



WEST from the valley of the Mississippi the stratified 

 formations which underlie the prairie region 

 spread over thousands of square miles nearly as horizontal 

 as when they were deposited. Here and there they have 

 been ridged up into anticlines, now deeply trenched by 

 denuding agents, or have had wedges of the ancient 

 Archaean rocks thrust through them, along the flanks of 

 which their upturned beds can be examined in detail. 

 Hence in spite of their prevalent flatness opportunities 

 are afforded for tracing their stratigraphical succession 

 from top to bottom. They reach a maximum of thickness 

 of some seven or eight miles. Yet throughout this vast 

 depth of strata the unconformabilities seem to be nearly 

 all of local and unimportant character. The several 

 geological systems follow each other continuously, and 

 generally in such a sequence of insensible gradation as to 

 show that geological history in that part of the globe was 

 marked by comparatively few great and destructive 

 geographical revolutions. The record of this history 

 remains in an almost unbroken series of strata from the 

 Primordial zones up into the older Tertiary formations. 



Here surely if anywhere in the world there should be 

 a tolerably ample chronicle of the sequence of living 

 creatures, so far at least as regards marine forms. If the 

 intermediate types, so much desired by the evolutionist, 

 are ever to be found imbedded in the rocks of the earth's 

 crust, surely here we may expect to find them. An 

 area of continuous tranquil deposit, and of slow subsi- 

 dence, unaffected for almost the whole of geological time 

 by serious upheaval, metamorphism, or unconformability, 

 containing within itself a well-nigh unbroken record of 

 geological changes — a very promised land for the paleon- 

 tologist ! Hardly more than a dozen years have passed 

 since this great region began to be systematically searched 

 for organic remains. Yet during that brief period what 

 treasures have come from its teeming strata ! New orders 

 of Vertebrates, some of them of extraordinary types, have 

 thence been added to the long roll of organic forms. 

 Other orders, scantily developed in Europe, and pre- 

 viously but little known, have been ascertained to have 

 teemed in these far western plains. Whether we regard 

 the prodigious number of individual specimens, and the 

 great variety of genera and species, or the marvellously 

 perfect state of preservation in which the remains occur, 

 there is no other known area where facilities for palaeon- 

 tological research of the most minute and thorough kind 

 exist so abundantly. 



Thanks to the labours, first of the universally-honoured 

 Joseph Leidy, and then of his younger successors. Marsh 

 and Cope, the firstfruits of that rich palajontological 

 harvest have already been gathered In the Yale College 

 Museum alone about 1,000 new species of extinct \'erte- 

 brates have been received from the West during the past 

 Vol. xxii. — No. 568 



twelve years, at least one-half of which remain to be 

 investigated. Mr. Cope's museum at Philadelphia is like- 

 wise crowded with new forms. If such results have been 

 achieved merely by expeditions equipped for at most but 

 a few months of such labour as is possible at present in 

 these wilds, what may not be looked for when some of the 

 habitable portions of the fossiliferous regions come to be 

 searched, when quarries, railway cuttings, and other arti- 

 ficial openings add to the opportunities of exploring the 

 rocks, and when systematic fossil-hunting can be carried 

 on from a near centre of supplies, instead of from a base 

 several thousand miles away in the Eastern States ! 



Among the organic wonders of which from time to 

 time during the past decade announcements have ap- 

 peared, none have been received with more interest than 

 the discovery of birds with "teeth, made by Prof. Marsh 

 near the end of the year 1S70, in the middle Cretaceous 

 rocks, which in Kansas and Colorado spread out east- 

 ward from the base of the Rocky Mountains. The more 

 striking features of this remarkable transitional ornithic 

 type were described by i\Ir. Marsh as far back as 1872, 

 and are now tolerably familiar to naturalists from his 

 writings, and to geologists from the descriptions and 

 restorations which have appeared in scientific journals 

 and text-books. But its detailed structure has only now 

 been made known in the splendid monograph on Odon- 

 tornithes which has just appeared. This work is intended 

 to form volume vii. of the Geological Exploration of the 

 40th Parallel, carried out by Mr. Clarence King for the 

 Engineer Department, and also to stand as the first of a 

 Series of memoirs of the Peabody Museum of Yale College. 

 As a fitting termination to the noble Survey series of 

 quartos, and as a splendid forerunner for what we hope will 

 prove a long and illustrious series of memoirs from Yale, 

 the volume is doubly welcome. The splendour of paper, 

 printing, drawing, and engraving (and in the advanced 

 copy with which we have been favoured, the sumptuous- 

 ness of binding) that have been lavished on the work 

 bespeak preliminary acknowledgment. 



So perfect a matrix do the peculiar buff, chalky, or 

 marly beds of the Kansas middle Cretaceous formations 

 furnish for the preservation of organic remains, that 

 almost every bone of the skeletons of some of the birds 

 has been recovered. The materials for the study of 

 their osteology is thus almost as ample as that for any 

 living bird. Full advantage of this abundant store of 

 material has been taken. The cases and cellars in the 

 Peabody Museum at New Haven contain the remains of 

 about fifty different individuals of a single bird. Every 

 bone of its skeleton, with the e.xception of one or two 

 terminal toe-bones and the extreme point of the tail, 

 has been recovered, and is here carefully drawn of the 

 natural size. Never before has it been possible, we 

 believe, to reconstruct so perfectly so ancient an organism. 

 The volume is divided into two parts. In the first of 

 these the detailed structure is given of the bird on which 

 the author has bestowed the name of Hcsperomis. The 

 skeleton of this animal if extended to its full length would 

 measure abcvt six feet from the point of the bill to the 

 end of the tail. It must have been a typical aquatic bird, 

 without any power of flight, but with strongly developed 

 limbs and a long flexible neck, whereby it was doubtless 

 endowed with remarkable powers of diving and swimming, 



