Batesford Liwesfonr. 291 



the two species are occasionally met with on the Atlantic sea- 

 board of the British Ids. 



G. vesicularis is recorded by Howchin from Muddy Creek ; as 

 Ijeino; common in the Balcombian and rare in the Kalimnan. It 

 is interesting thus to note the certain influence of climatic 

 changes. 



In the Filter Quarries, not common. Specimens rather small. 



Gypsina hourhiiii, sp. nov. PL II., Figs, ia, h ; pi. III., Figs. 3-5. 



Description. — Test discoidal; opposite faces moi'e or less 

 slightly convex, rarely flat, or more rarely slightly concave. 

 Surface granulate to pustular, as in G. vesicularis. Chamber- 

 lets numerous, with a sub-concentric arrangement. Shell-wall 

 coarsely perforate. Central series of chambers globigeriniform 

 and surrounded by a series of small chamberlets, which in turn 

 is succeeded by the larger, normal chamberlets. No marked dif- 

 ferentiation of the chamberlets along the median plane wlien 

 examined in vertical section, except in their being more spacious 

 in occasional specimens. 



Diameter of test, 1.5 to 2.4mm. 



Observations. — A reference to the genus Gypsina as occurring 

 in the Upper Quarry at Batesford is made by Messrs. T. S. 

 Hall and G. B. Pritchard in their paper on the Lower Tertiaries 

 of the Moorabool Valley, which in all probability is the form 

 above described. I have much pleasure in naming this species 

 after Mr. W. Howchin, w^ho determined the genus for the above- 

 named authors. 



G. howchini is a very distinct form in the Batesford lime- 

 stone. It has the coarsely perforate structure of the chamber- 

 lets seen in G. vesicularis, P. and J. sp., but is invariably dis- 

 coidal. Dr. Goes figured a recent variation of the latter type, 

 from the Carribean Sea,^ which he named G. vesicularis. var. 

 discus: that form, however, has a differentiated median layer 

 of chamberlets as in the Miocene genus Miogypsina, but with- 

 out the vertical pillars, and the shell-wall is usually thinner. It 

 is probable that the species now described is a climatal modifi- 



1 Bull. Mus. Comp. Zool., Harvard Coll., vol. xxix., Xo. i., 1891, pi. vii., figs. ;'., 4-(;. 



