302 NTRIBUTIONS PROM Nil NATIONAL HERBARIUM, 



must, therefore, be ranked aa a variety of the above. The k 

 variety, found al Btation 280 the form called OdonUlla obtusa km. Ralfs.o 



It i- clearly .1 small variety of tin- Bpeciee, exact exam plea being easily found 

 in most large gatherings, as in the above-mentioned type-slide of EL L. Smith. But 



doubtful if this 1- the genuine OdonUlla obtuta Km/., which Beema to have 

 a much closer resemblance to /•' Grev.6 Thus Kutzing figures il aa 



other <li;it-'in than /.' also Ralfa,<* and under it- Bynony- 



moua name of 0. biddul\ v*igand< it also differ- greatly. I therefore have 



Dot included this in the above synonymy. />'. primordialis Brun/ 1- also omitted 



synonym. The figures of the two Bpeciee are often quite close. But t; 

 Bpecimensof.fi ilis are frequent in gatherings made at stations 2844 and 3 II 



and when these a*re compared with examples of B.edu ardsii the difference i> seen to 

 be far too wide to admit of their union. It is perhaps a comparison of the figures of 

 these two diatoms, rather than the specimens themselves, that haa led Grove to unite 

 them.0 I >■ Toni ' ootea the similarity of the two, but givea Brun's form Beparate rank. 

 I can nol agree with II . I.. Smith* in considering this Bpeciee aa "a hirsute variety of 



' V. " 



The Bpecimens found by me were mostly large forms, ranging from 0.095 nun. in 

 station 3604 Bering Sea to <». 1 l nun. in Btation 2848, south of Alaska peninsula. 



Found at Btations 2287H, 2807, 2848, 3604, 3693H, W13H, off Alaska peninsula, to 

 Bering Sea and south to Honshu Island, Japan. 



Biddulphia extensa Mann. sp. now Plate XI.YIi. in.i res I. 2. 



Valve an elongated and perfectly symmetrical ellipse, about four and one-half times 

 aa long as wide, elegantly beaded with fine, round, closely sel heads, radiating from a 

 Bmall circular hyaline central area, the lines bo arranged aa to form concentric ellipsea 

 on either half of the valve, these extending from the circular central area to the bases 

 of the long vertical horn- arising near the apices of the valve; of the lines radiating 

 fr< 'in the center only the 1 wo coinciding with the median transverse axis straight . the 

 others curving in conformity with the two ellipses; two stout, straight .and long spines 

 Bet on opposite Bides of the central area, half way betw< en the valve's longitudinal and 

 transverse axes, and Bpread upward and outward: in zonal view the valve showing tin- 

 two horn- to be long, tapering, and vertical, and broadened into a flat-topped apex, this a 

 little higher than the much elevated central area; the base of the valve joined to the 

 girdle by a curved line; approximate valves of adjoining frustulea united by the 

 tipsof the horns and further connected by a pellucid film-like silicious membrane 

 at the center, parting and narrowing toward the apices; the two centra! areas almost 

 touching, and the four long Bpines arising from these interlocked, the two from each 

 valve being on opposite sides of the other valve. 



In the single dredging in which this species was found it is abundant; but I have not 

 been able to find any certain remains of the connecting girdle. 



Length ><i valve, 0.130 mm; width of valve, 0.028 mm. 



Type in I . S. National Museum, No. 590137, from station 4505 1 1 . Santa Cruz light- 

 house, Monteny Bay, Cal. ; 10 fathoms. 



•i Hour. Synop. pi tOO. f. 11 /;. 1881. 



Quart. Journ. Micr. Sci. 7: pi 8.J. 11 IS. 1859. 

 ■ Km/. Bacill. 137. pi 18. VI 1 1./. / ... 6 8. L844. 



Pritch. Hist. Infus. ed. 1. 848. pi IS.f. SO 3 I L861. 

 1 lledw. 2: 15. pi :../". ./. I860. 



rMem. Soc. Phys. et Bist. Nat. Geneva 81 1 : 12. pi tS.f. 9, pi r,.f. 9. L891. 

 V Schmidt. Atlas pi i: :. 

 » De Tom. Syll. Alg. 2: B64. L894. 

 I Am. Jomm. Micr. 4: L01. Lfi 



