18 p. T. CLEVE, ON SOME NEW DIATOMS. 



The C. Ecclesinnus Grev. (1857) is as Mr. Janisch correctly states the same as 

 C. fenef<tratus Grev., which is the entire frustule. Mr. Janisch proposed (1863) the 

 name C. Rabenhorstianus, but which should be changed for the older name of Gre- 

 viixe's. The type of this extremely variable species, especially abundant in the Ca- 

 ribbean are;i, has alternating longer and shorter costaj and an area not surrounded by 

 a circlet of puiicta. The form from Gallapagos Islands is therefore distinct, but, con- 

 sidering the great variability of the species, I am inclined to regard it only as a 

 variety. 



The stellate markings on the disc are very variable, and in some specimens 

 Avanting. 



2. Campylo discus Margaritarum Cl. N. Sp. 



CostEE numerous, covering about "/s of the disc, interrupted by a fine line and 

 surrounding an elongate area, where some fragmentary punctate lines are visible as the 

 continuation of the costal. 



Diam. 0,06 mm. 



PI. IV, fig. 52, ^"Vi. 



Pearl Islands rare (Eugenie Exp.). 



In its general form this species resembles C. angularis Gkev., but is different. 



Plagiogramma Grev. 



1. Plagiogramma rutilarioides Cl. N. Sp. 



Small, rhombic, more or less elongate, with two converging costjB around the 

 centre, but not near the ends. Structure: transverse punctate lines, 15 in 0,01 mm. 

 Margin with one or two sets of larger puncta, which probably are the bases of bristles. 



Length 0,030,0425 mm. Breadth 0,010,013 mm. 

 PI. IV, fig. 54, >-7.. 



Port Jackson, Australia (Eugenie Exp.). 



2. Plagiogramma spinosum Cl. N. Sp. 



Valve narrow, constricted in the middle, then dilated, and again constricted. 

 Costae 2 strong, around the centre. Ends slightly capitate. Structure: puncta, arran- 

 ged in regular transverse rows, 10 in 0,01 mm. and in irregular longitudinal lines. 

 The margin of the frustule is furnished with a row of sliort setaj or bristles. The 

 ends of the valves have blank (not punctate), oval areas. 



Length 0,08 mm. Breadth 0,01 mm. 

 PI. IV, fig. 55, 7,. 



The marginal setoa are visible when the frustule lies in an oblique position. 



Gallapagos Islands rare (Eugenie Exp.). 



This form has the same general outline as P. carihbteum Cl., P. lyratvm Grev 

 and P. Barbadense Grev. It is most nearly akin to the latter, but the ends are dissi- 

 mihar and the structure different. 



