112 Miss Agnes Crane — Evolution of the BracMopoda. 



Note. — " The Brachiopoda need not detain ns long," writes Prof. 

 S. J. Hickson, M.A., D.Sc. Lond., on p. 115 of " The Fauna and 

 Flora of the Deep Sea," 1894 (Modern Soienc^ Series). It is, 

 perhaps, just as well they did not, for we fail to comprehend his 

 subsequent remarks thereon in the light of modern research. 

 "Atretia," he proceeds, "is the only genus peculiar to deep water." 

 If by "peculiar" he means that the genus is found in deep water 

 exclusively (the usual sense of the word) we would refer him to 

 the types of Atretia Brazieri, Davidson, which have been preserved 

 for some years in the Davidson Collection in the Geological 

 Department of the Natural History Branch of the British Museum. 

 This Australian species was determined, named, and described by 

 Dr. Davidson (see Proc. Zool. Soc. Lond. p. 181, April, 1886), 

 for his "Monograph on the Kecent Brachiopoda" (Trans, of the 

 Linn. Soc. of Lond. 1886-1888, vol. iv. Zoology, p. 175, pi. xxv. 

 figs. 16, 17a). Therein he will find the Australian species of the 

 genus was obtained by Mr. John Brazier off Port Stephens, New 

 South Wales, in twenty-five fathoms, which can scarcely be regarded 

 as "deep water." Much has been learned and published with regard 

 to the distribution of the recent Brachiopoda since the publication 

 in 1880 of Dr. Davidson's "Eeport on the Brachiopoda of the 

 Challenger Expedition," which was the first issued. 



With regard to Prof. Hickson's further statement as regards 

 Lingida, moreover, it can no longer be maintained " that shells 

 almost identical with those of the living species are found abundantly 

 in the Cambrian strata." It has been repeatedly observed in recent 

 years by Hall, Clarke, Beecher, and Schuchert that ti-ue Lingida 

 first appear in the Trenton series of the Lower Silurian epoch. 

 The Cambrian species, formerly referred to that genus, are now 

 known to belong to more primitive genera, Lingulella and Lingu- 

 lasma, and that these were preceded by various Oboloids and 

 Obolelloids and the radical Paterina. If the diagram of generic 

 evolution which accompanied the first part of my paper in the 

 February Number of this Magazine dispels the persistent illusion 

 respecting the primeval antiquity of the genus Lingida, and its 

 unchanged persistence since early Cambrian time, it will have 

 served its turn. Of the manifold imperfections of that " attempt to 

 indicate the ordinal and main generic relations of the Brachiopoda," 

 no one can be more aware than the writer. Since its publication 

 I have been favoured, through the kindness of the authors. Professors 

 James Hall and John M. Clarke, with advance sheets of the final 

 chapter — "the Evolution and Classification of the Genera of the 

 Brachiopoda" — of their excellent "Handbook of the Brachiopoda," 

 now on the eve of publication in America. The classification 

 appended is a judicious and compact one, combining their own 

 views with those of Waagen, Beecher, and Schuchert. Including 

 Paterina, which is placed outside the pale of both the sub-classes 

 Lyopomata and Arthropomata, as belonging exclusively to neither, 

 but a parent source of both, and excluding Eichioaldia and Aida- 

 corhjnclius as " Incertse Sedis," no less than three hundred and 



