148 



Locality: Adriatic (Quarnero) ! Mediterranean (Genua), not vcry 



rare. 



Differs from L. Elirenbergii by the form of the valve and the 

 fincr striae. In this latter respect resembles the var. icnuistrìata of 

 L. Ehrmbergii which howewer has the same shape of valves as /.. 

 Ehrenbergn. L. mediterrajiea is smaller and has cuneate valves. 



12 L. flabellata var. parva Mer. 



Differs from the type species by its smaller size and the girdle 



Length o.oòi 



face which is broader and cuneate. -rrr — ttz ^"t; — j-- " — 



Breadth or the girdle tace co io 



O.OÓ5 o.o65 O.OÓ8 0.078 0.079 o.o855 0.089 0.093 o.ogS 0.121 o.iSg 



0.024 0.0295 X 0.018 0.023 0.025Ò 0.020 0.019 0.0295 X 0.019' 



breadth of the valve o.ooòò5-o.oo7Ó mm. 



Locality: California (San Fedro, Monterey), common! Sumatra, 

 not rare. 



It is not on single occasionai small specimens that 1 bave established 

 this variety, but on whole gatherings where it predominates or wherc, 

 as in one gathering from Monterey, it is to be found in an almost 

 pure condition. The size of the type species varies from o. iii to 

 0.415 mm. The largest forms (from Adria, Fola) surpassing o.3 mm. 

 can be distinguished as forma major. 



i3. L. gigantea Mer. 



Valve slightly davate, gradually attenuated from the summit to 

 the lower end, with only slightly concave margins; superior apex 

 rather broad, rounded, not attenuated, lawer end narrow, with apex 

 inflated (as in L. flabelìatd). Pseudoraphe distinct, striae fine, invisi- 

 ble with an ordinary magni fying power. Girdle face very narrow, 

 with the upper part abruptly broadened and limited by parallel mar- 

 gins, lower part very narrowly cuneate, upper angles slightly roun- 

 ded. Septa superficial, straight, septal puncta small, quite marginai, 

 secondary puncta little developped. Endochrome granular. Length 

 0.277-0.323 mm., breadth of the girdle face 0.020-0.027 mm , breadth 

 of the valve 0.024-0.0256 mm. 



