ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 547 



displacement by which the bionic equilibrium will be disturbed. Hence 

 two faunas in their purity will always appear in succession in any single 

 section. 



As the geological chances are, in general, in one direction for any 

 particular region, the shifting of faunas is likely to be in the same 

 direction for long periods of time, and thus the recurrence of two dis- 

 tinct faunas is rare. Occasionally, oscillation of two faunas can bo 

 recognised in a single section ; this fact may be interpreted as migration 

 back and forwards over the same region. The occurrence of two faunas 

 each occupying a distinct metropolis will thus rarely ever show itself 

 in lapping of the faunas ; but occasionally evidence of the coexistence 

 of the faunas will be seen in the intercalation of a colony of one of the 

 faunas in the midst of the other. The lapping of faunas, stratigraphi- 

 cally, is the necessary interpretation of the coexistence of two faunas 

 at the same period of time. 



Dolphin Carp.* — M. Jaquet has made a careful analysis of that 

 strange malformation of the carp's head which is known as " carpe 

 dauphin " or " Mops Karpf." The most deformed parts aro the ethmoid, 

 the vomer, the prefrontal, and the upper jaw. There is a reduction in 

 the number of bones in the periorbital chain, and the superior maxillary 

 is formed of two pieces instead of only one as in the normal carp. 



Carboniferous Cestracionts and Acanthodians.t — C. E. Eastman 

 notes that coincident with the ma v ked increase of Pelmatozoa and 

 certain families of Brachiopods during the Lower Carboniferous all over 

 the world, a race of sharks armed with crushing teeth suddenly acquired 

 dominance, became exceedingly diversified, and finally all but passed 

 away towards the close of the Palaeozoic. Of the very extensive group 

 represented by the Cochliodonts and Cestraciodonts, which is at least 

 as ancient as the Devonian, only one genus, the so-called Port Jackson 

 shark, survives at the present day. With this all the fossil forms agree 

 in having similar but more or less specialised dentition, so that this 

 creature stands in the same relation to the host of Carboniferous sharks 

 with crushing teeth thnt Nautilus does to fossil Cephalopods. He goes 

 on to discuss Edestus and Campyloprion, Ctenacanthus and Acanthodes. 



Lamarck, Life and Work.} — A. S. Packard has executed a labour 

 of love in this study of Lamarck's life and work. In spite of the 

 meagre materials, the author has constructed an interesting biography. 

 This is followed by an estimate of Lamarck's many labours, a discussion 

 of the appreciation and depreciation of these, a history of evolution- 

 theory, and a chapter on neo-Lamarckism. No small part of the value 

 of this interesting work lies in the translation of carefully selected 

 passages from Lamarck's works. 



Introductory Text-book of Zoology.§ — D. S. Jordan and H. Heath , 

 have added another to many introductory text-books of zoology. After 

 briefly discussing the characteristic? of living things, and of animals as 



* Bull. Soc. Sci. Bucarest, x. (1902) pp. 542-7 (2 pis.). 



t Bull Mus. Co i.p. Zool. Harvard, xxxix. (1902) pn. 55-99 (7 pis. and 14 figs.). 

 X Lamarck, the Founder of Evolution, his Life and Work, New York, 1901. 8vo, 

 xii. and 451 pp. and 10 pis. 



§ Animal Forms, London, 1902, 8vo, vi and 258 pp. an 1 140 figs. 



