72 



SCIENCE. 



[Vol. XXI. No. 52c 



the grayish pulverulent appearance of the extremities that tlie 

 wear was greater on the ends than on the sides, thougli it should 

 be remarked that this pebble was probably thrown sideways 

 quite as frequently, if not more frequently, than endwise against 

 its neighbors. 



THE GENERIC EVOLUTION OF THE PALEOZOIC 

 BRACHIOPODA. 



By AfiNES CRANE, BRIGHTON, ENGLAND. 



It is a time-honored saying that "a prophet is not without 

 honor save in his own country," but the name and fame of Pro- 

 fessor James Hall, LL.D., director of the State Museum of Natu- 

 ral History of New Yorlj, and its veteran State geologist, are 

 well known in Canada and the United States and have long been 

 recognized and appreciated among the geologists and invertebrate 

 palceontologists of Europe. The highest recognition in geological 

 circles was accorded him nearly a quarter of a century ago, when 

 he was awarded the Wollaston Medal of the Geological Society 

 of London, the year after Barrande, and a year before Charles 

 Darwin received it. His arduous life-long researches have re- 

 sulted in the production of the fine series of monographs of " The 

 Paleeontology of New York," of which Vol. VIII., Part I., 

 Brachiopoda,' by James Hall, assisted by John M. Clarke, has 

 recently made its appearance, with an unusually interesting text 

 and the well-executed plates for which the series has been re- 

 markable. As a fossil brachiopodist Professor Hall ranks with 

 his eminent contemporaries, the late Dr. Thomas Davidson, 

 F.R.S., and Joachim Barrande of Prague. In one respect he may 

 be said to take higher position as a philosophical investigator, 

 inasmuch that he kept free from prejudice with regard to the 

 theory of evolution as applied to the class Brachiopoda at a time 

 when, owing to the condition of our knowledge of the group, it 

 was not possible to adduce actual proofs of the logical postulate 

 in that direction. 



Times and methods have changed indeed since the celebrated 

 Bohemian palaeontologist definitely proclaimed that the evidence 

 of the Cephalopoda "■ and of the Brachiopoda ^ was opposed to the 

 truth of the theory of evolution, and Dr. Davidson, in answer to 

 a personal appeal from Darwin, replied that he was unable to 

 detect direct evidence of the passage of one genus into another.* 

 There has been a marked advance in the philosophical treat- 

 ment of this important group of ancient and persistent organisms 

 during the last decade, and to this progress American scientists 

 have contributed largely. Mr. W. H. Dall has differentiated and 

 described some new genera and species of the recent forms of 

 interest and value. Professors Morse, Brooks, and Beyer, and 

 of late Dr. Beecher and Mr. Clarke, have revealed suggestive 

 phases in the developmental history of typical genera and well- 

 known species. Now Professor James Hall and Mr. J. M. Clarke 

 have sifted and compared the vast accumulations of data recorded 

 by earlier writers by the older methods of descriptive palgeontol- 

 ogy , and, combining the results thus gained with the best features 

 of the new school of investigators, have effected a revolution in 

 the general treatment of the entire class of Brachiopoda. They 

 trace important stages in the phytogeny of the fossil forms and 

 various links connecting them through their immediate successors 

 with the surviving members of the group. 



Much of this work could not possibly have been accomplished 

 had it not been for the mass of descriptions and figures of the 

 vast number of species recorded in the works of Barrande, David- 

 son, De Koninck, D'Orbigny, Defrance, Deslongchamps, Suess, 

 Lindstrom, Pander, Quenstedt, Geinitz, Littell, Oppel, Oehlert, 

 Waagen, and Neumayr, in Europe, and Billings, Hall, Clarke, 

 Meek, Shumard, Worthen, Walcott, White, Whitfield, and others 

 on the continent of America. 



' Natural History ot New York. Pateontology, vol. vlil. (Geological Survey 

 of the State of New York), " An Introduction to the Study of the Genera of 

 Palffiozoio Brachiopoda." Part. I. By James Hall, State Geologist and Pate- 

 ontologlst, assisted by John M. Clarke. Albany, 1892. 



2 Cephalopodes, Etudes Gendrales par Joachim Barrande, Prague, 1877, 

 p. 234. 



3 Brachiopodes, Etudes Locales, Ibid, 1879, p. 206. 



* " What is a Brachlopod? " by Thomas Davidson, F.E.S., Geological Maga- 

 zine, Decade II., vol. Iv., 1877. 



The warm and discriminating recognition of the valued labors 

 of his European fellow- workers is one of the most agreeable 

 features of Pi-ofessor Hall's new volume. It is pleasant to read 

 "of the greatest of all works on the Brachiopoda by Thomas 

 Davidson," of the just appreciation of Barrande"s herculean efforts 

 in the Silurian field, of the excellence of William King's anatomi- 

 cal investigations, to find Pander's early work valued and his 

 names restored. These are just and generous tributes to the 

 memory of comrades who have gone before most welcome in these 

 latter days of that strident "individualism " which is often mere 

 egotism in disguise. 



The New York palaeontologist's recent work is not only a criti- 

 cal resume with descriptions and figures of the Brachiopoda of 

 New York, but a careful analysis of the results of the labors of his 

 predecessors and contemporaries in the same extended palaeozoic 

 field of research in the United States, Canada, Russia, Sweden, 

 and Great Britain. This gives it a cosmopolitan value, and 

 affords opportunity, by means of critical comparisons of genera, 

 species, and varieties from the geological horizons of both hemi- 

 spheres, to recognize the identity of species, to define synonyms, 

 to collate genera and sub-genera, to indicate their interrelation- 

 ships, and to illustrate the passage-forms linking one group, or 

 assemblage of allied genera, to another. To this branch of the 

 subject we must now restrict our observations. 



With singular modesty the authors refrain, for the present, 

 from proposing any new scheme of classification. The primary 

 division of the class into two orders comprising the non-articulated 

 and articulated genera is adopted. We fail to see why Owen's 

 names of Lyopomata, or "loose valves," and Arfhropomata, or 

 "jointed valves," should have been discarded, for they define the 

 same limits and distinctions as Huxley's simpler, but later, names, 

 Articiilata and Inartieidata, the first of which was employed by 

 Deshayes to designate certain forms of Brachiopoda before the 

 publicatian of Huxley's "Introduction to the Classification of 

 Animals." In England it is generally conceded that the priority 

 and scope of Owen's orders were clearly established by the Ameri- 

 can systematist. Dr. Theodore Gill. The matter, however, is of 

 less moment now that a general tendency to admit greater ordinal 

 sub-division has arisen. Waagen has proposed six orders, Neu- 

 mayr eight, and Beecher four, based on the peduncular opening 

 and associated characters. 



Tlie names Inartieidata and Articulata express certain general 

 distinctions. Nevertheless, it is a matter of fact ttat forms have 

 often appeared which cannot be separated thus, for tendencies to 

 transgress these artificial limits become apparent in various direc- 

 tions. For instance, the species of the Silurian genus TriTnerella 

 was shown by Davidson and King to be but feebly articulated, and 

 now Neobolus. Spondyldbolus, and Hall'^ new linguloid genus, Bar- 

 roisella, are shown to exhibit the same propensity. We are glad 

 to note that, although fifteen years have elapsed since the publi- 

 cation of the Memoir on the Trimerellidce, by Thomas Davidson 

 and WiUiam King,'^ it is frankly admitted that later observations 

 have hitherto added comparatively little to the results achieved 

 by those eminent investifjators and have taken away nothing 

 from their value. 



In the present publication the semi-artificial, but convenient, 

 family designations are not adopted, but the genera discussed fall 

 into groups of associated genera, often exhibiting intermediate 

 characters, which link one genus naturally with another. More 

 has been accomplished in this direction than could possibly have 

 been anticipated, and the eighth volume of the Geological Survey 

 of the State of New York (Palaeontology) would have made glad 

 the heart of Darwin, for its dominant note is the evolution of 

 genera. 



Hitherto Lingula has always been regarded as taxonomically 

 at the base of the Brachiopoda in spite of the acknowledged com- 

 plexity of its muscular system and the dale of its appearance in 

 the geological series. It is now shown conclusively to be devel- 

 oped from an obolelloid type which culminated in a faunal epoch 

 anterior to the appearance of Lingula, and Brook's history of the 

 development of the living species is cited as confirmatory proof 

 5 Quarterly Journal of the Geological Society ot London, vol. xxx., p. 124, 

 1874. 



