68 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



in Monterey Bay, Calif., the original locality of Greville's type speci- 

 men, unmistakably shows that it is not a Coscinodiscus but an 

 Endictya. This fact will be set forth in an illustrated article now 

 under preparation. Meanwhile a study of Greville's figure in Micro- 

 scopial Journal for 1 865, plate 1 , figure 8, as well as the one in Schmidt's 

 Atlas, plate 65, figure 9, called C. subvelatus Grunow, also from Mon- 

 terey, and the unnamed figure in Schmidt's Atlas, plate 62, figure 16, 

 from Monterey, will make evident how Endyctia-like these illustrations 

 really are. That the true generic character of that diatom was not 

 long ago suspected is due to the fact that Greville 's type specimen is 

 lost, as stated by Rattray, and further, the lack of any illustration of 

 the girdle view of the diatom, which is typically that of Endictya. 



COSCINODISCUS MICANS A. Schmidt 



(Schmidt, Atlas, pi. 139, figs. 2-3.) 



C. radiosus Grunow, especially as figured by Janisch (Gaz., Exp., 

 pi. 5, fig. 9) is rather close to this. 



COSCINODISCUS NANO-LINEATUS, new species 



Plate 14, fig. 4 



Valve circular, moderately convex to the margin; areolation linear, 

 not radiating, the beads largest at the center and closely set, slightly 

 decreasing toward the margin and proportionally more widely spaced ; 

 a single row of short, stout, sharply pointed spines next to the margin 

 and pointing outward. 



Diameter, 0.027 mm. 



This appears to be essentially the species represented by the 

 unnamed figure in Janisch's Diatoms of the Gazelle Expedition, 

 plate 20, figure 16. It is also like the doubtful example of C. lineatus 

 Ehrenberg in Schmidt's Atlas, plate 59, figure 30, except that lineatus 

 is not at all convex, its areolation is not progressively smaller from 

 center to margin and the apiculi are minute or absent . To unite the 

 above uniformly unlike and minute species with G. lineatus is there- 

 fore to negative most of the specific characters of the latter. In fact, 

 Schmidt in his Atlas, plate 114, figure 13 declines to unite the form 

 there figured with C. lineatus solely on the ground of its convexity, 

 a procedure which is perhaps to arbitrary and is rejected by Rattray 

 in his Revisi -n of the Coscinodiscus (p. 473). 



Type.— Cat. No. 43613, U.S.N.M. 



COSCINODISCUS NITIDULUS Grunow 



(Schmidt, Atlas, pi. 58, figs. 20-21; Van Heurck, Synopsis, pi. 132, fig. 2.) 



This is another species common to Campeche Bay and the Philip- 

 pine Islands. 



