31 1 CONTRIBUTIONS FROM Mil NATIONAL HERBARIUM, 



Bide of each apex, cun ing slightly to that side, then recun ing toward the ventral side 



in .1 1 ful arc and terminating at .» small, rectangular, hyaline central 



ventral side; markings of closely set, moniliforn • e except 



I the apices, where they are alightl} incurved; beading >f the striae alike on both 



I ih«- raphe, which is bordered on each side by a narrow hyaline space; a hyaline 



line, the width of one r-'w of beads, forming a narrow Btauroe transversely acrose the 



center, from the rectangular central area to the dorsal Bide. 



• li of valve, 0.135 mm.; width "i" valve, 023 nun. Striae, 76 in <». i mm . 



Type in the I . 8. National Museum, do. 590153, from Btation 3688H. < Okhotsk 

 August 27, 1896; 1,562 fathoms, bottom of brown mud and fine sand. 



some resemblance between the above and I < leganai iregory; ■ butt 

 Bpecies is more attenuated, especially as to the apices, and is much more delicately 

 marked. Thus l>e Toni says of it, 6 "Valvis gracilibus, Bemilunatis, levibus Btriis 

 obsoletis)." h resembles more Btrongly .t. i> • is < rregorj . ■ a similarity which is, how- 

 ever, accidental to Schmidt's figure, as can be seen by comparing it with the original 

 d< Bcriptionand figures,** 4 rregory saying that his form i- - \ ery hyaline," and that "the 

 Btriae are \ erj fine, about 60 in 0.001, very hyaline and hardly to be seen with a power 

 of lOOdiam." Schmidt's figure is therefore quite deceptive. 



Amphora crescens Mann. >p. oov. I * i \ i i XLIV, ik.iim. 3. 



«a punctata Grun.? Schmidt, Atlas pi. !8.f.& L8 



Valve Blightly convex on the dorsal Bide, more rapidly curving toward the rounded 

 and incurved ends; the margin appearing ribbed because of the transA erse Btriae; ends 

 bent in ward into rounded wings extending beyond the vent ral line of the rest of the 

 valve and hyaline along their inner edges; raphe beginning near the ends, close to the 

 dorsal margin, almosl Btraight until near the middle, then curving \ entrally i<» the two 

 central nodules, which are distant from the ventral Bide one-fourth the width of the 

 valve; v entral margin slightly convex at the center, si raighl or slightly concave between 

 this and the rounded ends; trans> erse striae obscure, excepl where seen in relief along 

 the dorsal margin; markings di fferenl on the two sides of the raphe; on the dorsal Bide 

 consisting of rows of beads, three to five in a row, the smallest next to and touching the 

 raphe, increasing regularl) in size to the last at the dorsal margin; these rows alternating 

 with the striae visible at the margin, equidistant, 11 in 0.1 nun., transverse at th< 

 ter of the valve, thence outward gradually inclining toward the ends; on the> entral 

 Bide the rows Bhorter, of two or thr< e beads of nearly equal size, those Dearest the raphe 

 slightly larger; not touching the raphe, bul uniformly distant the width of one bead, 

 thus leaving a hyaline line along the raphe on the ventral Bide only; rows absent at the 

 middle for the width of two rows, thence at firsl inclining from the central area, half- 

 way to their becoming transverse, from there outward gradually inclined from the 

 ends, thus making them at this point confluenl with those on the dorsal Bide of the 

 raphe; al the rounded ends of the valve the ventral rows Dot reaching the margin, bul 

 leaving these hyaline on their inner edges. 



Length of valve, 0.09 mm. ; width of valve, 0.013 mm. Headed striae, 11 in 0.1 nun. 



Type in the U.S. National Museum, no. 590158, from Btation L516H, Gulf of Cali- 

 fornia, December 22, L904; 1,627 fathoms. 



This species bears a significant general resemblance to the figure in Schmidt's Atlas/ 

 Darned .1. c assa punctata Grun. The figure is very poor, making il impossible to Bee 

 whether or Dot there are headed Btriae present, though the varietal name implies that 



Trans. Micr. Soc. Lond. n. b. 5: To. pi /../'. SO. 1857. Moeb. Diat.-taf. pi. tt. t 



b De Toni, Syll. Alg. 2: 381. 1891. 

 Schmidt, Atlas, pi. > I ■ L875. 

 d Tran~. Roy. Soc. Edinb. 21: 51 I. pi. /.'../" ; ,. b c. L857, 

 ' PI. 



