284 The Philippine Journal of Science im 



irregularly disposed. The chief subgeneric types of Orbitoides 

 are based on the appearance of the chamberlets of the median 

 layer. 



The genus Lepidocyclina has lozenge-shaped or spatulate- 

 formed chamberlets. They occur in the Upper Cretaceous, the 

 Oligocene, and the Miocene. (Chapman.) 



Plate XI, fig. 1, is a photomicrograph of a thin section of the 

 orbitoidal limestone on Lantauan Ridge about 12 kilometers west 

 of Danao, Cebu. The horizon is probably uppermost Miocene. 



Douville 29 has recognized the following species in sections of 

 Philippine material which I submitted to him. 



Lepidocyclina insulse-natalis J. et Ch. Lepidocyclina smithi Douville. 



Lepidocyclina richthofeni Smith. Lepidocyclina verbeeki Newt, et Holl. 



Lepidocyclina formosa Schlumb. Lepidocyclina inflata Provale. 



Lepidocyclina inermis Douville. Lepidocyclina cf. marginata Mich. 



I shall figure only two species here. 



Lepidocyclina insulae-natalis Jones et Chap. Plate XIII, figs. 6 



and 7. 



Monograph Christmas Island. London (1900), PL XX, fig. 5. 

 Samml. d. geol. Reichs-mus. in Leiden (1888-1902), I, 6, 128. 



These are very much enlarged drawings of the swollen central 

 portion of this species. These pea-like swellings from which 

 the surrounding wing-like parts have been worn away are more 

 common than the whole specimens. 



Figs. 13, 14, 15, and 16 are drawings of various fragments 

 of the same. These were all found lying loose on the surface 

 of the small hill in the lower Kahumayhumayan Valley in Cebu. 

 The original containing-limestone has been removed, and the 

 underlying rock was found to be coal measure shale. I feel 

 convinced that these forms were weathered out of a limestone 

 which lay stratigraphically below that on the neighboring hill 

 summits. 



Similar forms have been found in Java and Christmas Island, 

 and doubtless they are pretty generally distributed in this region. 

 Those from Christmas Island have been determined by Chapman 

 as L. insulse-natalis, though Douville figures practically the same 

 thing as L. richthofeni Sm. This last name, however, was given 

 by me, at an earlier date, to an entirely different form of which 

 the chief outward character was its more bulging and rounded 

 shape. 



"This Journal, Sec. D (1911), 6, 71-74. 



