.MANN- DIATOMS OF THE ALBATROSS VOYAGES. 271 



Actinoptychus molleri <i rim.: Schmidt, Atlas pi -- 1890. 



In our specimens the cenl ral area ia formed into a strong hyaline star by the exten- 

 sion of the ends oi the undulating segments. 



Found al station 2807, Galapagoe [elands. 



Actinoptychus planus Maim. sp. nov. Plate XI.V. pioi re 2. 



Valves circular, divided into Bix segments of equal Bize and identical markings, 

 their surfaces l> ing Dearly in one plane; three bearing each a minute globular proc- 

 ess, set "ii the extreme outer margin of the valve, the alternating three showing obscure 

 rudiments of such proc< 3s< - markings of minute beading closelj placed, not in per- 

 fecl rows, but bo arranged as to '_m\<- a faintly blotched or wavy appearance to the 

 Burface; do hyaline bands al the outer margins of the segments, but their out< 

 ners separated by .-mall triangular hyaline areas, the extremities of the six lines of 

 division; central area unusually small, circular, hyaline; rim a mere line, apparently 

 smooth. 



Diameter of vah e, 0.0525 mm. 



Type in the U. S. National Museum, No. 590126, from Btation 1029H, Bering - 

 June 27, L900; 913 fathoms, bottom of gray Band and day. 



Actinoptychus punctulatus Pant. Beitr. Bacill. Ung. 1: 62. pi. 8. f. 60. L887. De 

 T<mi. Notarisia 3: 608. 1888; Syll. Alg. 2: 1374. 1894. 



Actinoptychus intermedins Schmidt, Atlas pi. 91. f. S not/ 2), pi 109. f. 12. 1886. 



As is pointed ou1 by !>•■ Toni a , Schmidl has included under his name intermedium 

 two quite distinct forms. Thai represented by figure 2 in plate 91 should be taken 

 as type; the other tiL r . 3 . agreeing with Pantocsek's species, should be placed here. 



Found at stations 2807, Galapagos [slands, and 2920H and 3013H, between Cali- 

 fornia and Hawaii. 



Actinoptychus radulus Mann. sp. imv. Plate XI. V. FIGURE 3. 



Valve circular; divided into 6 equal segments, each bearing a stout, rounded proc- 

 ess, arising close to the rim and protruding Blightly beyond it . its base Burrounded by 

 a small oval or cuneiform, hyaline Bpace which narrows inward to a thin line running 

 to the center of the valve thus bisecting the segment; markings of minute beads 

 regularly arranged in diagonal cross lines: each segment Blightly wider al the outer 

 margin than its length radially, thereby leaving an unusually large hyaline central 

 area: rim narrow, finely crossed with lines and bearing blunt, si >u1 teeth closely set, 

 giving to the miter edge a serrate appearance; the segments alternately slightly con- 

 cave and convex, as in many other species. 



Diameter of valve, 0.078 mm. 



Type in the U. S. National Museum, No. 590127, from Btation 2920H, between Cali- 

 fornia and Hawaii. November 21, 1891; 570 fathoms, bottom of brown mud and fine 

 sand. 



Actinoptychus splendens Shadl». Kali's in Pritch. Bist. [nf us. ed. 4. 840. 1861. Van 

 Hem-. Synop. pi. 119. ./'. / .'. ;. 1881." Pant. Beitr. Bacill. Ung. 1: 63. pi. 16. 

 f.140. L887. De Toni, Syll. Alg. 2: 1385.1894. Schmidt, Atlas pl.lSS.f 

 Actinophcu nia spl ruL ns Shadb.6 in Bright . Quart . Journ. Micr. Sci. 8: 9 1, pi. >.. f. is. 



I860. Moeb. Diat.-taf. pi. 29. f. is. 1890. 

 Malicmyx wncU nanus Ehrenb. and //. bisenarius Ehrenb. A.bh. Schli -. G« a. Vaterl. 

 (tilt. 1861-: pi. /../. /. 1861; 1862--. pi I A./. > L8 



Syll. Alg. 2: L374. L894. 

 &This name was originally published l>y Shadln.li in Trans. Micr. Soc. Lond. n. b. 

 2: l<i. 1854. The description is insufficient for a determination, bul Brightwell's 

 i<lemi.iication may be correct, inasmuch as he was a contemporary worker and may 

 have <een authentic material. 



