v Seme new s y Y) i) Aa ®) > 2 U = = Wel re AY 73: Zepeemb 1399 WANY. N-Gibson- inv ds Z = 77 ~~ SS SOME NEW AND RARE DIATOMS. WALKER & CHASE. 1886. ° A 649 Os4 I BS VA ase: preys. - vi bpd a pana eee a = 5697 W 33 NevEES On Some New and Rare Diatoms, isp 4 : W.C. WALKER, F. ®. M. S., Utica, New York, wi LIBRARY NEW YORK BOTANICAL GARDEN. AND HH. H. CHASH, M. D., Geneva, New York. Dimeregramma Baldjickii, Ralfs; (Brightwell.) A good view is given of this much-named Diatom. Brightwell was the first to figure and describe it; we give the synonymy : Odontidium Baldjickii, Brightwell, M. J. 1859, p. 180, Pl. 9, Fig. ¥. Dimeregramma B., Ralfs, Pritchard's Infusoria, p. 791, 1861. Rhaphoneis B., Grunow, Austrian Diats., p. 879, 1862. Achnanthes B., Grunow, Arctische Diat., p. 21, 1880. No satisfactory reason for this latest change is given; from an examination of a large num- ber of specimens we are inclined strongly to place it back in the Genus Dimeregramma, Ralfs, /. ¢. The essential characteristics of Achnanthes preclude the entrance of this Diatom, as we have no record of a frustule having different valves, one of which possessed median and terminal nodules ; Rhaphoneis is characterized by moniliform striae; Dimeregramma Baldjickii is costate, the coste being 10 in .0OL inch; the valves are very uniform in size, being .003 inch in length, by .0015 inch wide-—Habitat, Baldjick, Turkey. Plate 1, Fig. 3. Biddulphia Imperialis, N. Sp.. W. C. Walker. Large; 10-angled; angles acute, with prominent horn-like processes; distance between angles .00229 inch; diameter of valve .0076 inch ; sides deeply concave; valve surface divided into two portions, the inner circular portion 4 SOME NEW AND RARE DIATOMS. occupying three-fifths the diameter of the valve, coarsely areolated with hexagonal cells; outer part coarse and irregular in areolation; entire surface punctate, puncta arranged in radiant lines. Habitat, Sandwich Islands; W. C. Walker. Plate I, Fig. 1. This exceedingly beautiful species of Biddulphia is well figured in our illustration, and is” very large; it belongs to the subdivision of which B jfavus is the type, as is evidenced by the corrugated border and radiant punctation ; the central circular portion, which is much de- pressed from the surface-level of the remainder of the valve, suffices to at once place it as an en- . . . 4 tirely new species; several examples having been observed by Mr. Walker. Biddulphia formosa, var. pentagonalis, Witt. Valve large, 5-angled, angles _ slightly rounded: processes smooth, prominent; cellulation radiant, being that of B. formosa (Tri. ceratium) except that near the margin the cellules suddenly grow smaller; processes smooth. — Diameter between angles .0037 inch. Habitat, Pacific Soundings. Plate 2, Fig. 9. This species is figured in Schmidt’s Atlas, plate 79, f. 4; the figure in our plate is from a valve in our possession ; as several valves have been noticed, we think the variety is one that will be sustained. Biddulphia crenulata, N. Sp., W. C. Walker. Valve large, circular; margin ere- nated and striate; from 4 to 8 prominent mesi circular progesses, which are intra-marginal and smooth; surface of valve finely punctate, puncta in radiant rows. Diameter of valve .004 inch. Habitat, Challenger Sounding, No. 237, Pacific Ocean. W.C. Walker. Plate 2, Fig. 7. } (Quite a number of valves of this interesting and beautiful species have been found by Mr. Walker, in one of the Challenger Soundings; in accordance with the views of the most advanced students we place this as a Biddulphia, to which Genus the vast majority, if not all of the mem- bers of the Genus 7riceratium will be relegated; the new genera “ Lampriscus” and “‘ Odontella- Lampriscus” of Grunow, must be condemned. Amphiprora cornuta, N. Sp., H. H. Chase. Valve large, .0063 inch in length, by .0033 inch wide; deeply constricted at centre ; extremities round, bearing a large, round, smooth, prominent process; striation very fine, extending two-thirds the distance to the centre, leaving an oval, smooth space in the middle of each lobe; margin strongly banded. Habitat, Tuscarora Sounding, 2,240 fathoms, Pacific Ocean. H. H. Chase. Plate I, Fig. 6. A very peculiar Diatom, and one very difficult to classify, but the twisted keels seem to de- termine that it should be placed in the Amphiprore ; the oculi at the extremities are quite similar to those of Au/iscus; the striation is very fine, being 55 in .001 inch. Amphipleura maxima, N. Sp., H. L. Smith. Structure and general characteristics those of Amphipleura; length of valve .0145 inch; striae 80 in.001 inch. Habitat, Fossil deposit, Klakamas, Oregon. Plate 2, Fig. 5. SOME NEW AND RARE DIATOMS. 3 A very interesting species of this noted Genus; its enormous size, which is quite uniform in several individuals, and the coarse striation at once place this as a different species from any yet observed ; the ends of the median line have a slight elongation; there is also visible in the median line the distinct rudiment of a central nodule; the figure in our plate lacks these points, but otherwise is reliable. Aulacodiscus Kinkerianus, N. Sp., E. 8. Nott. Dise large, .009 inch in diameter : lurid ; 5 to 7 rounded marginal processes; furrows conspicuous, extending but half way to the centre; umbilicus smooth and circular; granules minute, arranged in masses, which are radiant -on the outer half of the valve, but irregularly disposed on remainder. Plate 1, Fig. 9. Habitat, Moravian Earth; Mr. Edw. 8. Nott. One of the most striking members of a Genus full of curious and instructive forms; the valye, when the under surface is in focus, bearing a remarkable resemblance to Hupodiscus Argus, and when the other surface is in focus having an entirely different appearance. Mr. Nott fur- nished us with samples of this species early in the spring of 1885, and has requested us to eall it after his friend, Mr. Kinker, of Amsterdam, who furnished him with the material, which is a fossil deposit from Eastern Austria. Aulacodiscus grandis, N. Sp., W. C. Walker. Disc pale, distinctly bullate beneath the 5 to 7 very prominent submarginal processes; granules small, distinct, arranged in radiant rows over entire surface of valve; furrows distinct, and placed on elevated ridges extending to centre of disc; umbilicus smooth and irregular; margin coarsely striated. Width, .0103 inch. Plate 1, Fig. 8. Habitat, Cambridge Estate, Barbadoes; W. C. Walker. This beautiful species possesses several interesting points: the central part of the valve is ele- vated to an equal degree with the furrows, and when in focus the remainder is so far without as to cause the whole to present the appearance of a five-rayed star; the very close arrangement of the beautiful pearly granules, and its large size, all combine to make this one of the finest of its kind. Aulacodiscus Stoschii, Janisch. Disc clear, with 6 or 8 minute, submarginal pro- cesses, situated on prominent thimble-shaped elevations; central half of disc elevated; granules arranged in radiant lines on the entire surface; rounded and distant on elevated portion of valve, but compressed and irregular in outline on remainder of surface; umbilicus circular and irregu- larly granular; margin finely striated; width .0088 inch. Gazelle Expedition, C. Janisch ; Cam- bridge Estate, Barbadoes. W. C. Walker. Plate 1, Fig. 2. This species of a genus that has furnished the Diatomist with so many beautiful forms, is figured by Herr Janisch in Fig. 11, Plate 34, of Schmidt’s Atlas. It presents several distinctive- characteristics; the thimble-shaped elevations; the deeply-depressed spaces between the processes, 4 SOME NEW AND RARE DIATOMS. and the altering appearance of the radiant lines of cellules. The illustration gives an excelle nt idea of the general appearance of this form. ; Aulacodiscus mammosus, (7rev., in Transactions Mic. Society, 1863, p. 70, Plate 4. Fig. 13. We give asketch of this unique species, in our Plate 2, Fig. 11, and herewith append Dr. Greville’s notes thereon : ‘ Dise very prominently bullate beneath the processes, the bullations close to the margin and forming elevated cones; processes long, cylindrical; furrows open, composed of two parallel rows of granules reaching the umbilical blank space. Diameter .0038 inch; elevation of bullation and process above surface of dise, .0012 inch.” Aulacodiscus decorus, (rev. ‘Large, colored; disc with numerous submarginal processes; furrows open, well defined by parallel lines of granules, terminating in very small blank spaces surrounding the processes; granules minute, irregularly disposed in the centre, soon passing into closely moniliform slender — lines with intermediate shorter ones.” Plate 2, Fig. 10. Habitat, Barbadoes. Width of valve, .0078 inch. Auliscus czlatus, Bailey, var. gigas, Ebr. An enormous variety of the above Diatom, from Island of Iquique, South America; valve slightly oval; diameters .005 inch x .0057 inch. Well shown in Plate 2, Fig. 12. Auliscus stelatus, N. Sp. H. L. Smith. Valve small, rhomboid-oval ; .0022x.0030 inch; umbilicus small, smooth, circular; rays radiant from center in four directions, oculi large, compressed from centre; surface of valve studded with pearly granules. -Habitat, Island of . Iquique, S. A. H. L. Smith. Plate 2, Fig. 4 + These two species occur in the same gathering from Iquique, (not Guano.) Synedra ulna, var. Chaseana, B. W. Thomas. Valve slender, .0214 to .0296 in length ; striae 17 in .001 inch, extending across the valve ; no blank space in centre; extremiti constricted and rounded. Plate 2, Fig. 3. Habitat, Lake Michigan; Mr. B. W. Thomas —~ , a This Synedra is notable for its very great length, some specimens in our possession being one- thirty-second of an inch long, and none less than one-fiftieth ; the striae are 28 m .001 inch; a good idea of its appearance is given in the figure. Synedra affinis, var. Baileyana, H. H. Chase. Valves small, from .00114 to .0034 inch in length; striation that of \ afinis, 33 in .001 inch; valves variously bent and constricted. Habitat, Brazihan Coast. Plate 2. Fig. 1, a—d. ng Oe A very remarkable appearing species, quite common in a marine gathering from Maranheim, South America; the normal form is given in Fig. 1; a few of the many variations shown in a—d. re SOME NEW AND RARE DIATOMS. 0 Triceratium Febigeri, N. Sp., W. ©. Walker. Valve triangular: distance between angles .006 inch; margins straight, interrupted midway by a convexity; angles rounded ; surface of valve coarsely granular; granules small and irregular at centre and angles, but larger and arranged in rows on remainder of surface. Habitat, Barbadoes:; W. C. Walker. Plate 2, Fig. 6. This is one of the most curious and interesting species yet given up by that apparently exhaust- less wonder-land, the Barbadoes fossil deposits. The peculiar appearance can be better under- stood from a study of the illustration in our plate, which is a faithful representation of it. pa» Ver , Podosira’ Pacifica, NeSp., H. H. Chase. Large, measuring .0039 inch in diameter ; finely striated over entire surface, striae radiant from center; margin wide and coarsely striated ; middle third of valve with from 18 to 30 large, circular openings, giving a coarse, seive-like ap- pearance. Habitat, Pacific Ocean soundings; H. H. Chase. Plate 1, Fig. 5, illustrates this beau- tiful and peculiar species, but does not show the radiant striation on surface of valve, which, how- ever, 1s similar to that on other species of Podosira. Solium exculptum, Heiberg, var. pentagonalis, Kitton. The normal Diatom is described by Heiberg, in his Conspectus, p. 52, Plate 4, Fig. 10; the variety with five angles is mentioned by Kitton, in his remarks ou the Diatomaceous deposits of Jutland, in the Quekett Club Journal for 1870, pp. 100, 102. Plate 1, Fig. 10. The Genus Solium, with Trinacria and Hemiaulus are placed by Heiberg in Ins Danish Con- spectus (1863) among the * Hemiaulidee genuine ;” the diagnosis of Solium is here given: ‘ Out- line of valve regularly quadrate or rhomboid ; frustule in front view with horn-like processes at the corners, terminating with the spines.” The diameter of the five-angled variety, as shown in our figure, is .0012 inch, and the distance between the processes is .0008 inch. Habitat, Island of Fuur, Denmark. Stictodiscus Grevilleanus, N. Sp., W. C. Walker. Valve large, slightly triangular; sides very convex; entire surface granulose, granules disposed irregularly on inner two-thirds of valvular surface ; arranged in close radiant rows on outer third; distance between angles .0048 inch. Plate 1, Fig. 4. Habitat, Barbadoes. .W. C. Walker. This very elegant and interesting Diatom is well delineated in the figure; its structure is most decidedly that of Stictodiscus, and could be referred to the Genus Pseudo-Stietodiseus, insti- tuted by Grunow for the reception of the following forms: Pseudo-Stictodiscus angulatus, (Stictodiscus) ; Ps.—St. Eulensteinii (Triceratium) ; Stictodiscus Eulensteinii, (Grunow.) H. H. Chase. o 9 ao lu 4 vd = ed bs eins a ee yes ii LU TAMA OS i/ ne a ee ee = r —— WALKER. & CHASE. eccu a cc Ca) oo§ Se feos ° r t.e0 ° Bo Sloe. oss _ we Pa * = wi i eS yi) ae. Se A, A. oe Se , wis d 7 wa ware ee Sty, 4A ; . ° * ‘ ' <3 .s u ’ = ’ « 4 ; ie 4 ie | oy z ’ . « : - : { ‘ y . <> * ¥ ‘ v ‘ a! ¥ . . - = . ? . i Ma ~ $ S, 1] 4 : i 1 . " S x * --* 'q . te r Vf p - « ‘ ‘ ‘ g “ s ‘D J . p r mY . 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