145 

 and more tender, the inner thin and compact. Ramification consists 

 of alternately very short and long branches bent in opposite dircc- 

 tions. Length 0.034-0.048 mm., breadth of the girdle face o.o23-().o35 

 mm., breadth of the valve about 0.0095 mm. 



Locality: Adriatic (Fola), not rare. 



The valve has the same shape as in L. dalmatica, being relatively 

 broader, but the girdle face is somewhat different: the septal puncta 

 are distinct and round while in the type species they are indistinct 

 and elongated ; the size is much smaller and the mode of ramifica- 

 tion is not regular and symmetric as it always is in L. dalmatica. 

 Varietas tenella has much more delicate outlines, the septa are less 

 profound (0.00 1 14-0.00 143 mm.), the valve and girdle face narrower 

 and the former with somewhat concave margins. 



6. L. dubia var. adriatica Mer. 



Valve narrovv, very slightly and gradually attenuated from the 

 summit to the lower end, sometimes somewhat abruptly attenuated 

 in the middle part, superior apex broadly rounded, inferior slightly 

 inflated. Pseudoraphe distinct, striae very fine, 24-25 (or more) in 0.0 1 

 mm. Girdle face narrow or very narrow, cuneate, often linear at the 

 upper part, with coarse outlines, upper angles slightly rounded. Septa 

 thin, straight, quite superfìcial,' septal puncta small, strongly margi- 

 nai. Endochrome granular. Forming small, tuftcd colonies on short 

 irregularly branched stipes, sometimes more elongated, with ramifi- 

 cation irregularly dichotomic; stipes structurless. Lenghth o.o5ó- 

 0.128 mm., breadth of the girdle face 0.0095-0.020 mm., breadth of 

 the valve o.oo57-o.oio5 mm. 



Locality: Adriatic (Pola), common. 



Much larger than the type species, which varies between o.o36 

 and o.o665 mm. 



7. L. dubia var. latior Mer. [fig. 3]. 



Valve rather broad, cuneate or elongated ovoid, slightly and gra- 

 dually attenuated from the summit to the inferior apex, which is 



10 



