MARINE DIATOMS OF THE PHILIPPINE ISLANDS 29 



the margin an equal number of shorter rows of double beads, 6 to 7 

 pairs of beads in length, alternating with the long double rows; 

 adjacent to the margin 18 to 24 small but evident semicircular proc- 

 esses, in some specimens at the tnds of the long radiating rows; in 

 others at the ends of the shorter interpolated rows. 



Diameter 0.056 to 0.086 mm. 



This beautiful diatom owes its delicate appearance to the fineness 

 of its beading and the artistic lace open-work pattern of its]arrange- 

 ment. I have named it in honor of the late Hon. Alvey A. Adee, 

 Assistant Secretary of State, whose skill as a photographer of the 

 diatoms was of exceptional quality. 



The species clearly belongs with Stictodiscus kossuthii Pantocsek 

 (Hung. Diat., vol. 3, pi. 26, fig. 395) and Actinodiscus Jiorologium Brun 

 (Le Diat., pi. 23, fig. 13). But no Stictodiscus has the terminal semi- 

 circular elevations of the Pantocsek form, and Actinodiscus isfespeci- 

 ally distinguished by sharp radiating ridges, terminating at the mar- 

 gin in ocelli or pseudonodules ; so that both of these assignments are 

 untenable. My specimens are especially unlike Stictodiscus in not 

 being evenly convex. As no complete frustule was found, the dis- 

 similarity of the two valves, referred to in the generic name, could 

 not be noted. But as several specimens were found showing varia- 

 tion in the radiating lines of beads, this characteristic may be assumed 

 to belong to the present species. 



Type.— Cat. No. 43581, U.S.N.M. 



Genus ARACHNOIDISCUS Ehrenberg 



ARACHNOIDISCUS EHRENBEKGII Bailey 



(Smith's Brit. Diat., pi. 31, fig. 256; Schmidt, Atlas, pi. 68, fig. 1.) 

 Genus ASTEROLAMPRA Ehrenberg 



ASTEROLAMPRA MARYLANDICA Greville 



(Micro. Journ., 1860, pi. 2, figs. 14-15; pi. 3, figs. 1-4.) 



ASTEROLAMPRA PRINCEPS Rattray 



(Rattray, Rev. Cose, p. 644; Castracane, Chall. Exp., pi. 5, fig. 5.) 

 My specimen has a diameter of 0.141 mm., and 26 rays. 



ASTEROLAMPRA VAN HUERCKII Brun 



(Brun, Espec. Nouv., p. 10, pi. 14, fig. 1.) 

 A typical specimen of this large and delicate diatom. 

 Genus ASTEROMPHALUS Ehrenberg 



ASTEROMPHALUS ARACHNE (Brebisson) Ralfs 



(Pritchard, Inf., pi. 5, fig. 66; Schmidt, Atlas, pi. 38, figs. 3-4.) 



