310 THE VOYAGE OF H.M.S. CHALLENGER. 



8. Druppula nucula, n. sp. 



Cortical shell thin walled, smooth, with irregular network ; its two axes bear the proportion 

 3 : 2. Pores subcircular or irregular, roundish, twice to four times as broad as the bars ; fifteen to 

 twenty on the half equator. Medullary shell spherical, about one-third as broad as the cortical shell. 



Dimensions. Major axis of the cortical shell 0'15 to 02, minor axis 01 to 014 ; pores O006 

 to 0-012, bars 0'03 ; diameter of the medullary shell 0'04. 



Habitat. Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface. 



9. Druppula elliptica, Haeckel. 



Haliomma ellipticum, Stohr, 1880, Paloeontogr., loc. cit., p. 88, Taf. i. fig. 11. 



Cortical shell thin walled, rough, or thorny, with irregular network ; proportion of the axes = 

 3 : 2. Pores subcircular or irregular, roundish, about as broad as the bars ; ten to twelve on the 

 half equator. Medullary shell half as broad as the cortical shell, irreguarlly polyhedral (with 

 crooked beams in its interior). 



Dimensions. Major axis 015, minor OD6 ; pores and bars O'OOG ; diameter of the medullary 

 shell 0-03. 



Habitat. Fossil in the Tertiary rocks of Sicily : Grotte (Stohr), Caltanisetta (Haeckel). 



10. Druppula prunum, n. sp. 



Cortical shell thick walled, smooth, with irregular network ; proportion of the axes = 5:4. 

 Pores subcircular or irregular, roundish, three to four times as broad as the bars ; seven to eight on 

 the half equator ; every pore is closed at the bottom by a thin membrane, perforated by four to six 

 irregular pores (like Stylatradus sethoporus, PI. 17, fig. 3). Medullary shell spherical, one-third as 

 broad as the cortical shell. 



Dimensions. Major axis 0'2, minor axis 016 ; pores 0'03, bars O'Ol ; small enclosed porules 

 O'Ol ; diameter of the medullary shell 0'05. 



Habitat. Mediterranean, surface, Portofiuo near Genoa, Haeckel. 



11. Druppula oliva, n. sp. 



Cortical shell thick walled, rough, with irregular network ; proportion of the axes = 5:4. 

 Pores irregular, roundish, three to four times as broad as the bars ; lobed or composed of several 

 conjugated porules (as in Lithapium halicapsa, PL 14, fig. 8) ; five to six large pores on the half 

 equator. Medullary shell ellipsoidal, about one-third as broad as the cortical shell. 



Dimensions. Major axis of the cortical shell 015, minor 012 ; pores 0'02 to - 03, bars 0'007 ; 

 diameter of the medullary shell 0'04. 



Habitat. Mediterranean (Corfu), Canary Islands (Lanzerote), Haeckel. 



