1893.] MICKOSCOIMCAL JOdKNAL. 165 



The blown elicit is very compact, hut contains:! few fia<^nicnts 

 of shells, crinoid joints, and a number of light spaces, highlv 

 crystalline, whose orijjin is to be traced to the replacement <jf or- 

 <i^anic life by crystalline matter. 



The white chert is more abundantlv ff)ssiliferous even to the 

 naked eye. but under the microscope it is one mass of fossil life. 

 crinoid stems beinj^ especially numerous. There arc a number 

 of forms belon<^in<; to tlie ijroup Porifera. or the order of sponj^es, 

 sponije spicules bein*^ found throuj^h the rock. 



Among all the sections there can be traced a great similarity. 

 The limestone, under the microscope, is seen to be quite uniform, 

 and confirms the observation made in the quarries that the abun- 

 dant and predominant forms are brachiopod shells. One section 

 showed the fossil Styliola, a pteropod shell, which often forms 

 whole masses of Devonian limestone. i)ut is verv rare in Ohio 

 Devonian. 



The study of the carboniferous limestone is as vet incomplete, 

 but a number of new facts are coming to light, and certain lime- 

 stones long regarded as unfossiliferous are found to contain a 

 variety of fossil forms, only revealed by the microscope. 



The Tariff on Microscopical Books. 



By CHAS. W. smiley, 



WASHINGTON, I). C. 



The effect of the tariff' on books may be well understood from 

 the following prices of microscopical books published in England. 

 We give the retail prices asked by Messrs. Watson & Son, of 

 London, and the prices asked for the same books by one or more 

 American firms : 



Europe. Atnerica. 



Beale — How to W^ork with the Microscope. . $5 25 $7 50 



Cooke — 1 ,000 Objects for the Microscope, . 3^ 50 



Davies — Mounting and Preparing Objects, . 37 i 00 



Griffitii & Henfry — Micrographic Dictionary. 13 12 20 00 



Hogg — The Microscope, . . . . i SS 3 00 



Slack— Marvels of Pond Life, .... 88 i 50 



Wood — Common Objects for the Microscope, 25 75 



Total, . $22 00 $34 25 



This shows an average increase in price of 65 per cent. The 

 duty is only 25 per cent., but there are express charges, custom- 



