Reviews — Fossil Beetles from Colorado. 379 



The mineral species are arranged in the customary order, and are 

 described concisely, but sufficiently fully for the purpose of 

 discrimination. Happy use has been made of heavier type to 

 emphasize the more important or prominent features. Under each 

 we find particulars of the chemical composition, hardness, lustre, 

 colour, streak, cleavage (if any), transparency or opacity, specific 

 gravity, simple blowpipe reactions, and crystal form. We may 

 throw out the suggestion that now that portable, trustworthy 

 refractometers are available, it would be advantageous in a subsequent 

 edition to include details of the refractive indices and of the double 

 refraction where it is present. In the case of a transparent substance 

 a measurement of the refractivity will often settle its identity 

 beyond doubt. The blowpipe reactions are such as can easily be 

 carried out with an ordinary portable outfit. To facilitate the 

 determination of mineral specimens, the more obvious physical 

 characters are tabulated at the end of the book on a series of folded 

 leaves; by consulting this table the inquirer may reduce the 

 number of species to which a particular specimen might belong to 

 two or three, and a reference to the fuller descriptions in the text 

 will lead to the proper identification. 



As a help to the prospector Professor Butler in a series of 

 appendices gives the retail prices of good to very fine cut stones, the 

 value of metals and minerals, a glossary of the technical terms and 

 expressions used in the description of minerals, a table of the 

 elements with their symbols and atomic weights, Mohs's scale of 

 hardness, and von Kobell's scale of fusibility. The information 

 given in the first appendix on the charges made by lapidaries for 

 cutting stones is not sufficiently explicit. In the case of " fancy " 

 stones the cost of cutting is based on the weight of the finished 

 stones, whereas for diamonds it is the weight of the rough material 

 that determines the cost, and the charge for faceting a diamond 

 works out at more than fifteen times what it would be for an 

 ordinary stone of similar size when cut. Few lapidaries undertake 

 both classes of work. The author seems to be unaware that the 

 standard weight practically all over the world is the carat of 

 one-fifth gram, and not as defined by him. He points out in a note 

 to the second appendix that the quotations for metals and minerals 

 are those prevailing before the War; inasmuch as the large increases 

 now obtaining will probably in most instances end with it, he has 

 refrained from giving them. The publishers are open to severe 

 criticism for their omission to give any indication of the date of 

 publication ; it is only the fact that the author in this note speaks of 

 the "European" war that any clue as to the date is afforded.. The 

 curious use of two very different kinds of paper militates against the 

 appearance of the book. 



II. — New Species of Fossil Beetles from Florissant, Colorado. 

 By H. F. Wickham. Proc. United States National Museum, 

 1917, vol. Hi, pp. 463-72, pis. xxxvii-ix. 



SOME fifteen new species are described and figured under almost 

 as many genera, Brachyspathus being new, while all are 



