CLARK: RECENT CRINOID FAUNA 7 



follows directly from the Maxwell theory of reflection and absorp- 

 tion. Experimental determinations of the total emissivity of 

 platinum have verified the derived relation. 



MINERALOGY. — Four new minerals. Waldemar T. Schaller, 

 Geological Survey. 



The following very brief notes of four new minerals are given 

 in order to secure priority, as it is desired to extend further the 

 optical determinations before the detailed papers are published. 

 The formulas given have all been derived from the completed 

 chemical analyses. 



Minasragrite is a blue hydrous vanadium sulphate from Min- 

 asragra, Peru. The monoclinic crystals dissolve readily in cold 

 water. The vanadium is quadrivalent and the mineral is a hy- 

 drous acid vanadyl sulphate with the formula V204-3S0316H20, 

 which is interpreted as (¥002)112(804) 3" I5H2O. 



^ernandinite is a green hydrous calcium vanadyl vanadate 

 from Minasragra, Peru. The analysis yields the formula 

 CaOV204-5V205l4H2 O, which may be written, as a metavana- 

 date as follows: [H4Ca(V202)][V03]iol2H20. 



Shattuckite is a blue hydrous copper silicate from the Shattuck 

 Arizona Copper Company's mine at Bisbee, Arizona, Its for- 

 mula is 2CuO 2Si02H20 and it is close to plancheite in com- 

 position but differs considerably therefrom in its optical prop- 

 erties. Shattuckite forms pseudomorphs after malachite and also 

 occurs as small spherulites. 



Bisheeite is found with the shattuckite and forms pseudomorphs 

 after the shattuckite pseudomorphs of malachite. In composi- 

 tion bisbeeite is identical with dioptase, CuO 81021120, but is 

 orthorhombic, pale blue to nearly white in color* and has distinct 

 optical properties. 



ZOOLOGY. — The geographical divisions of the recent crinoid 

 fauna. Austin H. Clark, National Museum. 



The division of the present crinoid fauna as a whole into satis- 

 factory zoogeographic regions has proved to be a task of no 

 little difficulty, chiefly because of the almost complete absence 



