6 ART. 5. — H. YABE : 



tsuke, Japan (PL II., fig. 1). Under the microscope, they appear 

 as dark compact lines quite distinct from the septa. They may 

 perform the same function as the ramifications or infoldings of 

 the primary septa, or the intercalations of auxiliary and trans- 

 verse septa, subdividing the chambers or chamberlets. 



Secondly, I am in doubt about the following remark of Prof. 



SCHELLWIEN.^^ 



" Es tritt sehr häufig eine Verdickung der zum Septum 

 umgebogenen Kammerwand ein, indem sich auf einer oder beiden 

 Seiten der Septallamelle Kalksubstanz absetzt, welche in der Regel 



dunkler gefärbt Sie wird in der Kegel erst nach der 



Bildung der neuen Kammervvand ausgeschieden zuweilen aber auch 

 schon, ehe die Bildung der späteren Dach wand erfolgt ist, wie 

 eine Beobachtung bei Fusulina japonica lehrt." In all my slices 

 of Fusulina I can find nothing which coincides with the above 

 description ; nor does the figure in his work to which he refers 

 show anything of the kind. In all cases, the boundary between 

 the calcareous substance of the primary septa and what he regarded 

 as produced by a secondary acretion is not distinct and under 

 the microscope they always seem to fade away on both sides. 



Thirdly, the true nature of the median lamella, which is the 

 direct continuation of the thin coverino- on the whole surface of 

 the wall, is also doubtful. Dr. Girty has already objected to the 

 long accepted view of the poriferous nature of the wall."^ Though 

 I am not in position to express anything definite here in regard 

 to this matter, I give in fig. o, pi. III., jui interesting case of a 

 natural staining of the wall. The figure shows a longitudinal, 

 slightly oblique section, of Neoschwogerina craticulifcra in a 



1) HcnELLAViEN : Die Fauna des Karnisclien Fusulinenkalks. P. 240. 



2) Ü1KTV : I.e. 



