30 



of the girdle face o.oi 14-0,020 mm., hreadth of the valve o.ooóòS- 

 0.007Ó mm. 



Locality: California (San Fedro), common. 



It is to Miss S. P. Monks of Los Angeles, who has assisted me 

 in many ways in my vv^ork, that I dedicate this species. The girdle 

 face has a very peculiar appearance not to be found in any other 

 species; the position of the large secondary puncta is also a very 

 peculiar characler. It resembles in many respects L. profundcsepiaia. 



25. L. montereyana Mer. [fig. 17]. 



Valve narrow, linear in its upper '/.„ abruptly attenuated in the 

 middle, becoming again linear and very narrow in the lower y^, su- 

 perior apex broadly rounded, inferior inflated. Pseudoraphe invisible, 

 striae very fine, about 23 or more in 0.01 mm. Septa deep (0.0166 

 mm.). Length o. ii3 mm. breadth of the valve 0.0076 mm. 



Locality: California (Monterey), very rare. 



The valve of this species has a form similar to that of L. remii- 

 loides Mer., but it is a very distinct species, the septa being deep 

 and the lower apex of the valve inflated. It differs from L. grandis 

 by the indefinite pseudoraphe which is very distinct in the latter, 

 the valve is also different. It has no dose relation to any other 

 species. 



26. L. ovulum Mer. [fig. 18]. 



Valve broad or very broad, ovoide, more or less abruptly atte- 

 nuated at the lower end, superior apex broadly rounded, not atte- 

 nuated (except in very large specimens), inferior apex narrow, roun- 

 ded and somewhat produced. Pseudoraphe indefinite, striae very fine; 

 about 24-25 in 001 mm. Girdle face rather broad, sometimes very 

 broad, cuneate, upper angles rounded, inferior apex sometimes very 

 broad and concave ; frustule robust. Septa superficial, straight, septal 

 puncta very large, somewhat deepened inwards, secondary puncta 

 usually absent. Endochrome granular. Forming more or less numerous 

 colonies on short, scantly and irregularly ramified stipes, with a con- 



