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Beaumontella langii

Beaumontella langii, (Wall 1965); Emendations: Morbey, 1975, p.41-42, as Hystrichosphaeridium langii; Below, 1987a, p.70-71, as Beaumontella langii.

Originally Hystrichosphaeridium, subsequently Polysphaeridium?, thirdly Dapsilidinium?, fourthly (and now) Beaumontella.

Holotype: Wall, 1965a, pl.6, fig.9; pl.9, fig.9
Stratum typicum: Hettangian-Sinemurian

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Original description as Hystrichosphaeridium langii: [Wall 1965, p. 165]:

Diagnosis:
Hystrichosphaeridium langii a small species of Hystrichosphaeridium with a microgranular test and a relatively small number (25-40) of short, open appendages with a minute lateral rim or divided tip.

Description:
The test is round, ovoid or subrectangular in outline, its wall thin and microgranular. Approximately twenty spines are visible in optical section, and they are equal to approximately 25 percent of the test diameter in length. The spines are small, and precise determination of the nature of the spine tip is difficult. They usually appear to be minutely bifurcate or trifurcate or even to produce several projections. Often the test is broken at one end, but not regularly so.

Dimensions:
maximum test dimensions 21-32 µm, spines 3-6.5 µm; holotype test 24x22 µm, spines 5.5 µm maximum.

Affinities:
Hystrichosphaeridium langii is similar to H. capitatum Cookson and Eisenack and H. rhabdophorum Valensi, but is smaller and bears less numerous spines.

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Emended descriptions:

Morbey, 1975, p. 41-42: as Hystrichosphaeridium langii:

Diagnosis:
Cyst chorate, cylindroidal, spheroidal, ovoidal or spherical. Wall thin, microgranulate, rarely folded.
Archaeopyle apical, represented by rupture of cyst at apex of longitudinal axis, not discernible on all specimens.
Processes hollow, compound or simple heteromorphic, possibly open distally, generally of equal length per individual, 25-75 in number, less than or equal to 50% of cyst length/diameter in length. Process bases constricted to widely curved, seldom confluent; stems cylindrical, tapered, conical, or lagenate, often slender and sinuous in development; terminations seemingly bifid, bifurcate, or trifurcate, with pointed or rounded tips-occasionally terminations collarette (ectophragm), or simple with truncate or pointed tips (?preservation).

Dimensions:
cyst length/diameter 14-30 µm; breadth 12-25 µm; process length 3-10 µm, diameter up to 2 µm; cyst length:breadth 1:1-3:1.

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Below, 1987, p. 71: (translated from German):

Description:
vesicle/plate arrangement on amphiesma (progn.) cop, pop, cap, 5', 3-4a, 7'', 7c, 5-6''', 2'''', ns. Cyst scolochorate, ovaloidal, equatorial diameter circular, size small; wall composed of thin pedium and luxuria; surface microreticulate, granular, prismatic and furnished with appendages, the length of which is individually constant and usually equal to 1/2 to 1/3 of the equatorial diameter of the cyst in different specimens, but can also be reduced, appendages thin, tubiform, truncate with delicate, often filled central canals and stellate distal expansions (cauli-florate), glabrous, basally insiderate, with one central intraareate appendage per area; accedation formula n[2], n[1], NRc/nc, n(1), NR(2)/n(2), n(3), n(4), sas, pas, ls, rs, pps, sps; the appendages number from 50-60* (*=numbers exemplified by present material) and are distributed as follows: secanterior series n[2] (4-5)*, primanterior series n[1] (7-9)*, cingulum nc (0, 7-9)*, primposterior series n(1) (9-10)*, secposterior series n(2) (0, 8-11)*, tertposterior series n(3) (5-8)* and quartposterior series n(4) (2-6)* as well as sulcal sas, pas, rs, ls, pps, and sps, complete reduction of the cingular and secposterior series possibly weel as of individual sulcal appendages; cingulum and series of appendages laevorotatory or planispiralled; archaeopyle apical, tn[2], operculum solvate, opercular pieces secate, general opercular formula [2](s)+2[2](s)+3[2](s)+4[2](s)+5[2](s)+n[2](s).

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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.

Beaumontella langii, (Wall, 1965a) Below, 1987a. According to Below (1987, p.70-71), has the following accedation formula: 4-5 secanterior, 7-9 primanterior, 7-9 cingular, 9-10 primposterior, 8-11 secposterior, 5-8 tertposterior, 2-6 quartposterior, plus sulcals. It is a small skolochorate, ovaloidal cyst, with a microreticulate to granular surface, bearing spines, which are about 1/3 to ½ of the equatorial diameter of the cyst. The spines are thin, tubiform, truncate with central canals and cauliflorate distal extremities. There is one central spine per plate and about 50 to 60 processes. The cingular and sulcal spines can be reduced in size. The archeopyle is apical with a solvate operculum, the opercular pieces are secate.
Size: maximum diameter 21-32 µm, processes 3-6.5 µm.
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