ECHINODERMATA - KU ScholarWorks - University of Kansas

HYPEROBLASTUS SOUTHWORTHI (Reimann)
Plate 9, figures 4-6
Pentrerniticlea southworthi REIMANN, 1935, p. 28, pl. 2, figs. 16-17.
Description.—The holotype is 8 mm. long by 6 mm.
wide, vault 3.5 mm. long, pelvis 4.5 mm. long, pelvic
angle 65 degrees. Four hydrospire folds are present on
each side of an ambulacrum.
Occurrence.—Middle Devonian, coral zone of Widder
beds, Hungry Hollow Formation, tile yard, Thedford,
Ontario, Canada.
Type.—Holotype, E11,816, Charles Southworth collection,
Buffalo Society of Natural Sciences, Buffalo, New
York.
Genus OROPHOCRINUS von Seebach, 1864
[=Codonues MEEK & WORTHEN, 1869; Mitra CUMBERLAND, 1826]
BLASTOID STUDIES 35
Type-species, by original designation.—Pentremites stelliformis
OWEN & SHUMARD, 1850.
Generic diagnosis.—Fissiculate blastoids with ten
spiracular slits, into each of which four or five hydrospire
slits open, anal opening separate between an
epideltoid and hypodeltoid plate, lancet exposed along
main food groove, with lenticular outer side plates
between primary side plates, rarely touching admedial
ambulacral margins; sublancet or fused hydrospire
plate present, and form conical to club-shaped in side
view, Mississippian, Europe and North America.
Remarks.—The genus Orophocrinus may have
been derived from a form similar to Pleuroschisma,
which has closed sinus areas and the cryptodeltoids
and superdeltoid fused to form an epideltoid.
OROPHOCRINUS STELLIFORMIS
(Owen & Shumard)
Plate 13, figures 4-9; text-figs. 36-39
Pentrenutes stelliforrnis OWEN & SHUMARD, 1850, p. 67, pl. 7, figs.
I 6a-b.
Description.—Calyx calcitic, club-shaped in side view,
pelvis conical, base flat and wide, summit rounded;
FIGURE 35. Hyperoblastus filosus angustus (REimANN),
Middle Devonian, Hungry Hollow Formation, near
Thedford, Ontario (Buffalo Soc. Nat. Sci., no. E13,055);
plate arrangement of anal area, drawn from polished
tangential section, X34. [Explanation.—An, anal opening;
CR, cryptodeltoid; Db, deltoid body; DI, deltoid lip;
Ds, deltoid septum; H, hydrospire; HD, hypodeltoid; L,
lancet; 0, oral opening; Sp, main side plate; Su, superdeltoid.]
strongly pentalobate in top view. Theca 17 mm. long by
19 mm. wide, vault 6 mm., pelvis 11 mm. long, and pelvic
angle on radial bodies 70 degrees. Basal circlet 5 mm.
long by 8 mm. wide, almost cylindrical, with three normally
disposed basals. The stem is large, round, about 3
mm. in diameter, with about 64 crenellae extending
radially inward about halfway from the circumference
FIGURES 26-34. Species of Hyperoblastus FAY, n. gen., Middle Devonian, North America.
26, 27. H. preciosus (REimANN), Hungry Hollow Formation,
near Thedford, Ont. (Buffalo Soc. Nat. Sci.,
holotype, no. E15,934); 26, anal area, X15; 27, main and
outer side plates of part of "B" ambulacrum, X45.
28. H. dotis (REimANNI), Hungry Hollow Formation,
Thedford area, Ont. (Buffalo Soc. Nat. Sci., paratype no.
E13,052); cross section of "E" ambulacrum, X15.
29-33. H. filosus (WHITEAvEs), Hungry Hollow Formation,
near Thedford and Arkona, Ont. (Geol. Survey
Canada, no. 3,660; Buffalo Soc. Nat. Sci., nos. E13,960,
E16,206); 29, anal area (no. 3,660), X15; 30, dorsal
view of basal circlet (no. 3,660), X15; 31, cross section
of ambulacrum (no. E16,206), X40; 32, cross section of
"A" ambulacrum (no. E13,960), X15; 33, main and outer
side plates of part of "C" ambulacrum, X40. 34. H.
goldringae (REimANN), Ludlowville Formation, Bay
View, N.Y. (Buffalo Soc. Nat. Sci., no. E21,160);
cross section of "D" ambulacrum, X40. [Explanation.—
An, anal opening; Bf, brachiolar facet; Bp, brachiolar pit;
C, canal (radial); CR, cryptodeltoid; D1, deltoid lip; H,
hydrospire; HD, hypodeltoid; L, lancet; 0, oral opening;
OSp, outer side plate; P, pore; Pf, pore furrow; R, radial;
RI, radial limb; Sp, main side plate; Su, superdeltoid; Z,
azygous basal.]