238 INTRIBUTIONS PROM Till NATIONAL HERBARIUM. 



f..ur more ;i Little lower and alternating, and i ring of smaller but Btout spinet around 

 the basal rim, I rive and unique aspect i" which there is n<> analogy in the 



forms here under consideration. A very much closer affinity is found in Melosira. 

 Manx membere of this genus have a level central area elevated above the rim 

 cylindrical or conical hoop or band. In fad ihi- might almost !>«• said to be i hanu 

 teristic of the genus. F • exampli -• faf nai nalia Brun, a where even the flaring 

 upper rim of t 1 » « - band <»r hoop, described above, i- perfectly paralleled; ale '■' 

 Schmidt, * where the ring of zonal processes is also paralleled. If we also remember, 

 we have here t'> d<> with Bmall diatoms, P. calcyftot being 0.06 to 0.075 nun. at 



0.83 mm. in diameter, we shall Bee we are well within the aver 

 Melosira. li will perhaps be eventually preferable to construct a nen genus for these 

 allied forms, especially if other Bpecies are found which retain the essential charac- 

 teristics of those already known; and this would have the advantage of simplifying 

 somewhat the complex group of forms dow included in Melosira. Careful attention 

 io ilir description and the figures of M especially n> the Eonal view, will 



Bhow that ii is clearly distinct from the Oamaru or Japan specin 



T\ pe in the U.S. National Museum, No. 590116, from Btation 2807, t ralapagos Islands, 

 April !. ls ss : B12 fathoms, bottom of Globigerina ooze and « oral mud. 

 Melosira febigerii Grun.) Mann. 



Podosira febigerii Grun. in Cleve & Grun. 8v. Vet. Akad. Handl. 17-': II!). L880. 

 Van Heur. Synop. pi. 84 .. L881. De Toni, Syll. Alg. 2: 1362. L894 



I Bee do reason for including this form, nor the others bo named in the above plate of 

 Van Beurck, in the genus Podosira. It" thai genus is to be defined as ii generally is 

 for full d< -tails of which .<»••■ under Podosira in this report i, and if Melosira and Podosira 

 an- to retain any valid mark- of distinction, such forms as the above can not be sep- 

 arated in. in Melosira. In ordei t<> avoid repetition in this report, tin- position of the 

 author in tin- matter must be considered in connection with hi- remarks under the 

 genus Podosira 



A- both Grunow and De Toni observe in the above citations, there is some resem- 

 blance between this species and the more robust and coarsely marked /'. hormoide* 

 Mont. Km :i species, by the way, thai Montagne rightly renamed Melosirahor- 

 moides.d 



Pound ai Btation 3607, Bering Sea. 

 Melosira medusa Mann. sp. nov. Pi \ii: I.. Plot 1:1: :'.. 



Valve with border and central area; the latter about four-fifths the diameter <>f the 

 valve, has in its center a lew. rugose, broad kn<>l> or boll, the rest of the area l>ein<: 

 thinly Bpotted with irregular flecks. The border, one-fifth the radius in width, begins 

 internally in a row of -mall, granular, wedge-shaped markings, from the points of which 

 proceed fine wavy line- to the margin. A circle separates tin- granulated part of the 

 border from the outer portion. The latter, three-fourths the width of the entire herder. 

 is delicately marked with transverse lines proceeding from the points of the granular 

 above stated, and with liner line- interspersed between them. The lines 

 Bometimes anastomi 



I diameter of valve, 0.078 mm. 



An unnamed figure of Schmidt's < ha- some resemblance to this specie-, though it 

 -.■em- entirely i" lack the peculiar circle of small beaded triangles within the striated 

 border. Schmidt there -ay-. " Nach Grove vielleicht cine innere Schale von Stepha- 

 nopyxis, vielleicht zu einem andern Genus zu ziehen." Neither of these suggestions 



"Schmidt. Atlas pi 



&Op. cit. pi. 180./. 



■ Km/. Bacill. 52. pi 19. f. si Imi. 



d Mont, m d'Orbig. Voy. Amer. Merid. 7: l* L839. 



i Schmi.lt. Atlas ///. 1896 



