L62 Ford and Bradley- Margarosanite. 



witl) the elimination of the- water and the substitution of cal- 

 cium oxide for the small amount of manganese oxide present : 



Theory for Analysis 

 PbCa.,(Si0 3 ) 3 recalculated 



SiO, 35-10 83'77 



PbO 4317 48-57 



CaO 21-73 22 66 



1 ()()•()() 100-00 



The name margarosanife, which is proposed for this new 

 species, has been derived from fj.apyapiTi)<;, a pearl, and aavis, 

 a tablet or hoard, in reference to its pearly luster and lamellar 

 structure. 



Mineralogical Laboratory of the Sheffield Scientific School 

 of Yale University. New Haven, Conn., 

 April 18th, 1916. 



Art. XXII. — On the Paleozoic Alcyonarian, Tumularia ; by 

 W. I. Robinson. 



The new name Tumularia is here proposed for the forms 

 which are now placed in the genus Stylaroea Seebach (1866),* 

 since that name was preoccupied by Milne-Edwards and Haime 

 (1851),f for a hexacoral from an unknown locality. A single 

 species, S. miilleri, was described by these latter authors and is 

 therefore the genotype. Later Milne-Edwards:}: found this 

 species to be identical with Porites punctata (Linnseus)§ and 

 as the only species of the genus was thus removed to Porites, 

 the name Stylarcea disappeared, because under the rules of 

 nomenclature the same name can not be used for two different 

 genera of animals. It was, however, inadvertently again 

 applied by Seebach || to a single species, Stylarma raimeri, from 

 the Silurian of Esthonia. This form is closely related to 

 ProtarattJ, but is distinct in several important characters, and 

 since the name given by Seebach is preoccupied, the name 

 Tumidaria is here proposed. 



*Zeit. dentsch. geol. Ges., vol. xviii, pp. 304-310. 

 + Polyp, foss. d. Terr. Pal.. Arch. Mus., vol. v, p. 143. 

 JHistfnat. d. Coral., vol. iii, I860, pp. 181-182. 

 §Syst. Nat.. 10th ed., 1758, p. 1277. 

 IfLoc. cit. 



