CALCARINA, TINOPORUS, AND BACULOGYPSINA. 367 



Calcarina d'Orbigny is clearly understood and is the first of the 

 names that can be used without question. 



In 1893 Sacco erected the Genus Baculogysina on account of the 

 uncertainty of identifying Montfort's Tinoporus. Sacco referred 

 to his genius Orbitolina sphaerulata Parker and Jones, 1860, which 

 is abundant in the white calcareous muds of Australia. This is the 

 reticulately marked species and this gives a definite genus and 

 species for that which may be known as Baculogypsina sphaerulata 

 (Parker and Jones). 



Giimbel in 1862 describes Calcarina tetraedra from the Eocene 

 and this is used as a synonym of Baculogypsina sphaerulata by vari- 

 ous authors. However, a reference to his figure shows the close rela- 

 tion between this and our species on plate 45, figures 1-5. A study 

 of the fossil material of Siderolites cdlcitrapoides shows that 

 the fossil species and the recent one from the Philippines are ap- 

 parently generically the same. They represent different species, 

 however, and probably our recent Philippine species is the same, or 

 very close, to that described by Giimbel from the Eocene. If this 

 is correct, the following key may be used for our six species. The 

 occurrence of Siderolites as a recent Philippine genus is in line with 

 that of other groups of animals which have now living in this region 

 species of genera elsewhere extinct. 



A. Test rotaliform throughout ; with peripheral spines, and a supplementary 



skeleton Calcarina d'Orbigny. 



a 1 . Test fairly smooth, spines smooth or channeled. 



b 1 . With few spines C. spengleri (Gmelin). 



b 1 . With numerous spines C. defrancii d'Orbigny. 



a 2 . Test hispid, spines hispid. 



b\ Flattened, very hispid, spines numerous C. hispida H. B. Brady. 



b a . Biconvex, hispid, centrally tuberculate, spines four or five, dis- 

 tinct C. baculatus (Montfort) ? 



B. Test with rotaliform young, hispid, later irregular with numerous large 



chambers, coarsely punctuate, usually three or four blunt spines, hispid 



. .. .. , .. . ,. .. \Siderolites Lamarck. 



in the young, reticulations not distinct \„.„ ,.. _„ . , 



[Siderolites tetraedra Gumbel. 



C. Test with very young rotaliform, not hispid, later irregular with numerous 



small finely punctate chambers, 4-8 or more sharp spines, not hispid. 



(Baculogypsina Sacco. 

 Baculogypsina sphaerulata 

 (Parker and Jones). 



A comparison of the distribution of Baculogypsina sphaerulatus 

 (Parker and Jones) and Siderolites tetraedra Gumbel shows very 

 striking evidence of a distinct distribution for each. In the Phil- 

 ippine region Siderolites tetraedra is widely distributed, and at some 

 stations very abundant, while Baculogypsina sphaerulatus has been 

 noted at but three stations in the area, and then as of rare occurrences. 

 In material from the Murray Island region of the Great Barrier Reef 



