Geology and Natural History. 477 



Part VII. Lower Mississippi River Basin. Pp. 35, xxxii ; 2 pis. 



No. 485. Surface water supply of Hawaii, July 1, 1917, to 

 June 30, 1918; N. C. GrOver, chief hydraulic engineer; C. T. 

 Bailey, acting district engineer. Pp. 169. 



Mineral Resources. Numerous advance chapters for 1917, 

 1918. 



6. Foliation and Met amor 'phism in Rocks; T. G. Bonney. 

 Geological Mag., vol. 6, pp. 196-203, and 246-250, 1919.— This 

 paper is a summary statement of the causes of foliation in 

 rocks, and is suggestive of the criteria by which an original 

 foliation is to be distinguished from that in metamorphic rocks. 

 Professor Bonney 's long experience began .about the time that 

 microscopic methods of rock study were introduced. It is easy 

 for him to support his conclusions with specific examples in 

 many parts of the world. 



Foliated rocks are classed as due to (a) motion of partly 

 solidified magma, or if associated with banding, in many cases 

 to movement of two partly mixed magmas; (6) pressure acting 

 on either igneous rocks or sediments, with later recrystallization 

 in most cases. Each class is illustrated by half a dozen localities 

 and references are given to conclusive descriptions, largely the 

 work of the author himself. Some descriptive passages seem to 

 indicate lit-par-lit injection, but the process is not named. 



F. F. G. 



7. Observations on Living Lamellibranchs of New England; 

 by Edward S. Morse. Proc. Boston Soc. Nat. Hist., 35, No. 5, 

 p. 139-196. — Although the shells of most of the species of marine 

 bivalves of the New England coast were described and figured 

 many years ago, notably in Gould's Invertebrata of Massachu- 

 setts, 1841, and in Binney's revision of the same, 1870, the 

 animals themselves have been but little studied. Professor 

 Morse has made observations extending over many years on the 

 living animals of New England lamellibranchs, and in this paper 

 describes and illustrates by excellent outline drawings such parts 

 of the living animals as can be seen protuding from the shells 

 when the animals are in full activity. Forty-eight species are 

 thus illustrated, in many cases with successive growth stages. 

 It is interesting to note that Professor Morse made one of these 

 drawings as early as 1855, since which time he has returned to 

 the study of the biology of the lamellibranchs as occasion per- 

 mitted until he has become acquainted with all except the more 

 inaccessible species. He justly deplores the apparently needless 

 alterations in the nomenclature of the species which have 

 occurred in the meantime. w. r. c. 



8. Elementary Biology ; An introduction to the Science of 

 Life; by Benjamin C. Gruenberg. Pp. x, 528 with 261 illustra- 

 tions. Boston and New York, 1919 (Ginn & Co.). — The pres- 

 ent tendency of biologists to emphasize the habits, life histories, 

 activities and economic importance of organisms is well illus- 

 trated in this excellent introduction to the Science of Life. The 



