Description of the new species Kittonia kempii (Biddulphiales: Kittoniaceae) with comments on Kittonia hannai P. Lefébure & Chenevière and Kittonia gigantea (Greville) De ToniAuthorSims, Pat A.0000-0002-0214-8303p. sims @ nhm. ac. uk; https: // orcid. org / 0000 - 0002 - 0214 - 8303p.sims@nhm.ac.ukAuthorWilliams, David M.0000-0002-0584-307Xd. m. williams @ nhm. ac. uk; https: // orcid. org / 0000 - 0002 - 0584 - 307 Xd.m.williams@nhm.ac.uktextPhytotaxa20222022-11-235732275285http://dx.doi.org/10.11646/phytotaxa.573.2.7journal article10.11646/phytotaxa.573.2.73fd5d86e-1214-4796-97df-fb30f3d2200f1179-31637349988Kittonia gigantea
(Greville)
De Toni 1894: 898
(
Figs 21–30
)
Basionym:—
Biddulphia giganteaGreville 1864: 13
, pl. 2, fig. 9
The original description of
Biddulphia giganteaGreville (1864: 13)
was relatively simple, referring only to the shape of the valves and the ‘horns’: “Side view more or less broadly elliptical, subacute, inflated; horns long, cylindrical, capitate; cellules large, radiating. Longest diameter about.0080” (
Greville 1864: 13
). The specimens described were from the “Barbadoes deposit, Cambridge estate”, with a drawing of just one valve (
Greville 1864
: pl. 2, fig. 9, see our
Figs 21, 22
;
Fig. 22
is a reproduction of the original drawing with the number 2770 and the Maltwood co-ordinates ‘15/31’ added in pencil enclosed in the black box added to the drawing by us;
Fig. 21
is the published drawing from
Greville 1864
: pl. 2, fig. 9). The drawing was clearly a composite of several specimens as the published illustration was of a complete valve (
Fig. 21
) and the specimen identified as the
type
somewhat fragmented (BM 2770,
Figs 23–5
,
Williams 1988: 19
). Greville had referred to other specimens: “Of this magnificent species I have seen several tolerably entire valves, besides fragmentary ones. Perfect horns, however, are very rare, as, being long and slender, they are readily broken off” (
Greville 1864: 13
, as noted above for
K. hannai
with the detached ‘horn’ given the named ‘
Archaeomonadopsis incerta
’ by Ramp 1940). Rather graphically, Greville writes of the valves that they are “like the ears of the Scottish shallow drinking-cup called a Quaich [A shallow two-handled drinking cup, a ‘Scottish cup of friendship’]”, and notes that “the outline is much narrower, more or less oblong” (
Greville 1864: 13
). At first, Greville referred to this species by the name ‘
Cerataulus giganteus
’, which appears on some of the slide labels (
Table 2
), but when published it was as a species of
Biddulphia
(
Table 2
). Inspection of these slides yielded a few specimens in varying degrees of completeness (
Figs 26–29
). Only the specimen from BM 2965 (
Fig. 30
) had a whole ‘horn’ still in place (
Figs 26–7
, arrow in
Fig. 26
; specimen from BM
2798 inFigs 28–9
has a partial ‘horn’, arrow). The various speCimens have lengths of 165–205μm, and widths a little smaller, roughly about half of the length, 75–100 μm. Greville’s illustrations (
Figs 21, 22
) suggest that the width is more similar in size than the aCtual speCimens. It is hard to account for this as Greville was normally exceedingly accurate in drawing his specimens. Our thoughts turn to the composite nature of the illustration (see
Ross 2002
for a discussion on the nature and meaning of original illustrations).
When Grove & Sturt described their genus
Kittonia
, they included
Biddulphia gigantea
. They first noted Greville’s species in their earlier description of
Biddulphia elaborataGrove & Sturt (1886: 325
, pl. 18, fig. 9, see also
Witkowski
et al.
2017: 378
and for SEMs see
Round
et al.
1990: 278
,
Jousé 1977
: pl. 84, fig. 13 and
Sims & Hendey 2002: 388
, figs 13–15), where they considered both to be a new genus (
Grove & Sturt 1886: 325
, full quote given above). For
Biddulphia gigantea
, “[…] through the kindness of W. Carruthers, Esq., F.R.S., of the Nat. Hist. Mus., been enabled to examine Dr. Greville’s authentic specimens of his
Biddulphia gigantea
(“T. M. S.,” Vol. xii., p. 13, PI. 2,
Fig. 9
), we find that the hyaline stalked processes terminate in nodular cellulose expansions larger than the small capitate ends shown in his figure. We venture to remove the form to this genus under the name of
Kittonia grevilliana
” (
Grove & Sturt 1887: 75
)
. Quite why they changed the specific name is not clear, but De Toni later provided the nomenclaturally correct name of
Kittonia gigantea
(Greville)
De Toni (1894: 898)
.
In their monograph on the genus, Brigger & Hanna also understood Greville’s protologue for
Biddulphia gigantea
to be composed not of just
one specimen
: “It seems quite obvious that Greville’s figure is a composite and stylized drawing. Grove & Sturt recognized this after examining authentic material but they did not clear the matter up by simply renaming the species without a good illustration. The specimens which we have shown here may or may not agree with one or more of the species represented by the original fragments [
Brigger & Hanna 1965
: figs 6, 7, 17, reproduced here as our
Figures 31–33
]. Possibly some day an opportunity will be presented to re-examine and check the original material and thereby determine if there be any diatom which can bear the name
Kittonia gigantea
according to the rules of nomenclature” (
Brigger & Hanna 1965: 2–3
). That request was partially satisfied by
Williams (1988: 19)
, who had the opportunity of examining the original pencil drawing of
Biddulphia gigantea
that Greville noted to have come from slide BM 2770 and the specimen found at Maltwood Finder co-ordinates 15/31 named as ‘
Cerataulus giganteus
’ (
Fig. 22
), which would be considered the
holotype
specimen (
Williams 1988
: pl. 23, figs 3, 4). But no further commentary was included.
Of the Greville specimens since identified as
Kittonia gigantea
, five were labelled ‘
Cerataulus giganteus
’ and four as
Biddulphia gigantea
(
Table 2
). Most specimens are fragments of valves with just a few retaining the ‘horns’ or parts of them (
Figs 26–9
). No detached ‘horns’ were noticed.
FIGURES 21–30:
Kittonia gigantea
Figs 21, 22: Drawing of
Biddulphia gigantea
(“Barbadoes deposit, Cambridge estate”,
Greville 1864
, pl. 2, fig. 9), Fig. 22 reproduction of the original pencil drawing with the number 2770 and Maltwood co-ordinates ‘15/31’ added in pencil (enclosed in the black box); Figs 23, 4, BM 2770, ‘
Cerataulus giganteus
’ (Maltwood Finder 15/31), Fig. 25, image of slide BM 2770; Figs 26–7, BM 2965, ‘
Cerataulus giganteus
’ (Maltwood Finder 25/14); Figs 28–9, BM 2798, ‘
Cerataulus giganteus
’ (Maltwood Finder 36/22); Fig. 30, image of slide BM 2965. Greville’s speCimens are length = 165–205 μm (see also
Williams 1988
, p. 19).
FIGURES 31–33:
Reproduction of illustrations in Brigger & Hanna of
Kittonia gigantea
(
Brigger & Hanna 1965
, figs 6, 7 and 17 = Figs 31–33, respectively)
TABLE 2.
Slide in BM with
Kittonia gigantea
; * = type slide; + = specimen not located; & = badly damaged slides, not usable at this time
Of the illustrations given by Brigger & Hanna of
Kittonia gigantea
(
Brigger & Hanna 1965
: figs 6, 7 and 17, reproduced here as our
Figures 31–33
), the most accurate is their figure 7 (our
Figure 31
).