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|Benson, 1966, p. 510-513; pl. 35, figs. 3-4:|
Cyrtopera laguncula Haeckel
Cyrtopera laguncula Haeckel, 1887, Challenger Rept., zool., vol. 18 p. 1451, Pl. 75, fig. 10.
?Eucyrtidium cuspidatum Bailey, 1856, Amer. Jour. Sci., vol. 22, p. 5, Pl. 1, fig. 12; Ehrenberg, 1862, Akad. Berlin Monatsb. (1861), pp. 298; 1873b, Akad. Berlin Abhahdl. (1872), Pl. 2, fig.15.
?Eucyrtidium cornutella Ehrenberg, 1862, Akad. Berlin Monatsb. (1861), p. 298; 1873b, Akad. Berlin Abhandl. (1872), Pl. 2, fig. 14.
?Stichopera pectinata Haeckel, 1887, Challenger Rept., Zool., vol. 18, p. 1449, Pl. 75, fig. 11.
?Stichophormis novena Haeckel, 1887, Challenger Rept., Zool. vol. 18, pp. 1455-1456, Pl. 79, fig. 9.
?Lithostrobus tetrastichus Haeckel, 1887, Challenger Rept., Zool., vol. 18, p. 1470, Pl. 80, fig. 6.
?Cyrtocapsa sp. Riedel, 1958, B.A.N.Z.A.R.E. Repts. ser. B, vol. 6, pt. 10, p. 244, Pl. 4, fig.11.
Long, slender, conical test with 7-10 or more annulated joints, the last joint (eight) in one specimen bulbous, with its mouth closed by a lattice with large, irregular, polygonal pores larger than those of its proximal portion and the joints above it; all other specimens apparently incompletely developed, without basal mouth closed. Joints of the test separated by annular strictures occupied by internal septal rings. Cephalis subspherical, nearly hyaline but with small (1-2 µm) pores separated by wide, heavy intervening bars; at its base four collar pores. A slender, conical apical horn extends from the apical bar which is a dorsal rib in the cephalic wall; in tests with apical horn completely developed the horn is very long and curves ventrally, its distal portion nearly perpendicular to the axis of the test. The dorsal and primary lateral bars extend a short distance as ribs in the thoracic wall and terminate in short, thin, inconspicuous spines; in a few specimens (including the one with its basal mouth closed) there are a few, thin, conical spines originating from the joints below the cephalis and arranged in three longitudina1 rows, apparently representing rudimentary supporting structures of raised, dorsal and primary lateral longitudinal ribs as in Cyrtopera laguncula Haeckel; in one specimen studied in a wet slide there are six, raised, equally spaced, longitudinal ribs joined to the test by a lattice (thus wing-like) and without constrictions in their outline at the level of each constriction in the test. The proximal four to five joints below the cephalis are of nearly equal length and increase only gradually in breadth, with 2-4 transverse rows of hexagonally arranged, equal, hexagonal pores per joint. The distal joints slightly longer than the proxima1 ones, of nearly equal length, but breadth of successive joints increases more abruptly and joints less cylindrical and more nearly campanulate; therefore, much broader distally; distal joints with pores slightly larger but similar to those of the proximal joints, with 5-8 transverse rows per joint.
Measurements; based on 3 specimens from stations 93, 60, and 115: maximum length of test 144-185 µm (of test with basal mouth closed 171 µm), of cephalis 16-17 µm; maximum breadth of test (last joint) 68-71 µm, of cephalis 18-22 µm; length of apical horn (one specimen) 221 µm.
Remarks. Riedel (1958, p. 244) states that the rare occurrence of specimens he identified as Cyrtocapsa sp. from Antarctic waters made establishment of their range of variation impossible. Specimens from the Gulf are even more rare, but one specimen mentioned above with its terminal mouth closed and the few with surface spines arranged in three longitudinal rows are identical with Haeckel's illustration of Cyrtopora laguncula Haeckel (1887, Pl. 75, fig. 10). The other species listed as being tentatively synonymous with this species may represent incompletely developed forms of C. 1aguncula. Riedel
(1958, p. 244) states that these forms may be identical, but until this species can be more closely defined it will not be known whether or not it represents one species or a group of species.
Distribution. This species or species-group is very rare in the Gulf. It is present at only 5 stations in the Gulf, namely 46, 56, 60, and 93 in the southern Gulf and 115 in the northern Gulf. It is, therefore, a rare member of the oceanic assemblage with little affinity for Gulf waters.
Riedel (1958, p. 244) states that specimens of his Antarctic species or closely related species, including some of those mentioned in the tentative synonymy, are widely distributed in sediments of the tropical Pacific and Indian Oceans and of the northern Pacific. Haeckel (1887, p. 1451) reported Cyrtopera laguncula Haeckel from the southern Pacific at "Challenger" station 298 located in the Humboldt Current off the Chilean coast. Eucyrtidium cornutella Ehrenberg (1862, p. 298) was reported from the North Atlantic near Greenland. Whether all these forms represent a single species or a group of species, they apparently are cosmopolitan.