MAEINE DIATOMS OF THE PHILIPPINE ISLANDS 15 



ACTINOPTYCHUS PARVUS, new name 



Plate 1, fig. 8 



Sector of valves about 12, all evenly pebbled with closely set bead- 

 ing, no superimposed network or anastomosing lines, no hyaline area 

 across outer ends of sectors or between them, and no hyaline line 

 bisecting each sector; a hyaline central rosette about one-eighth the 

 diameter of the valve; a small but evident process at the margin in 

 the middle of each sector; difference in focal plane of alternating 

 sectors slight — that is to say, undulation of valve surface small. 



Diameter 0.045-0.059 mm. 



Type.— Cat. No. 43565, U.S.N.M. 



This minute and delicate species, abundant in the Philippine Islands 

 and rather widely distributed elsewhere, seems to have been generally 

 overlooked, probably having been taken for a small variety of A. 

 splendens. It is figured in Schmidt, Atlas, plate 132, figure 15, from 

 a specimen from Yokohama, but is misnamed A. laevigatus Grunow, 

 a fossil species from Monterey, Calif., which it only slightly resembles. 

 This can be seen by comparing it with Grunow's original figure (Van 

 Heurck, Synopsis, pi. 122, fig. 7). It also is like the intermediate 

 A. biseptinarius Ehrenberg in Mikrogeologie, plate 33, section 16, fig- 

 ure 5, one of a long list of names given by Ehrenberg to similar or 

 identical species, basing the distinctions on the unimportant quality 

 of the number of sectors into which the specimens happened to be 

 divided. This entire series of over 100 names is therefore rejected 

 by diatomists. 



I incorrectly called a specimen of the present species A. moelleri 

 Grunow in my Diatoms of the Albatross Voyages (p. 271). It 

 resembles this, but only in a general way. 



ACTINOPTYCHUS SPLENDENS (Ehrenberg) Shadbolt 



(Van Heurck, Synopsis, pi. 119, figs. 1-4; pi. 120, figs. 1-4; Schmidt, Atlas, 

 pi. 153, fig. 16.) 



ACTINOPTYCHUS SUBANGULATUS A. Schmidt 



(Schmidt, Atlas, pi. 132, fig. 11.) 



Schmidt's figure represents a form with 16 sectors; my specimen 

 has 20 sectors. 



ACTINOPTYCHUS TRILINGULATUS (Brightwell) Ralfs 



(Schmidt, Atlas, pi. 1, fig. 20.) 



See reference under A. annulatus (Wallich) Grunow. 



ACTINOPTYCHUS UNDULATUS (Bailey) Ralfs 



(Pritchard, Infusoria, pi. 5, fig. 88; Schmidt, Atlas, pi. 1, figs. 1-6.) 



Both the typical form and many varieties of this cosmopolitan 

 diatom were found, including the untenable A. tenarius Janisch 

 (Schmidt, Atlas, pi. 1, fig. 2), which in Fricke's Verzeichniss of 



