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



The c. Ecdesianus Grev. (1857) is as Mr. Janisch correctly states the same as 

 C. fenestratus Grev., which is the entire frustule. Mr. Janisch proposed (1863) the 

 natne C. Rahenhorstianus, but which should be chaiiged for the older name of Gre- 

 ville's. The type of this extreraely variable species, especially abundant in the ca- 

 ribbean aren, has alternating longer and shorter costse and an area not surrounded by 

 a circlet of puncta. 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 

 wanting. 



2. Campylodiscus Margaritarum Cl. N. Sp. 



Cost£e numerous, covering about Va 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 costa3. 



Diam. 0,06 mm. 



Pl. IV, fig. 52, ""'U. 



Pearl Islands i'are (Eugenie Exp.). 



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



Plagiogramma Grev. 



1. Plagiogramma rutilarioides Cl. N. Sp. 



Small, rhombic, more or less elongate, with two converging costa? 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 0,03—0,0425 mm. Breadth 0,01—0,013 mm. 

 Pl. IV, fig. 54, "">'/,. 



Port Jackson, Australia (Eugenie Exp.). 



2. Plagiogramma sjjinosum Cl. N. Sp. 



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

 Costge 2 strong, around the centre. Ends slightl}" 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 shoit setaj or bristles. The 

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



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

 Pl. IV, fig. 55, '"Vi- 



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



Gallapagos Islands i"are (Eugenie Exp.). 



This form has the same general outline as P. caribbamm Cl., P. lyratinn Grev 

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

 milar and the structure different. 



