Page:Scientific results HMS Challenger vol 18 part 2.djvu/689

Rh 6. Distephanus speculum, Haeckel.

Dictyocha speculum, Ehrenberg, 1837, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 150; Mikrogeol., 1854, Taf. xviii. fig. 57, Taf. xix. fig. 41, Taf. xxi. fig. 44, Taf. xxii. fig. 47, &c.

Dictyocha speculum, Stöhr, 1880, Palæontogr., vol. xxvi., Taf. vii. fig. 8.

Dictyocha anacantha, Ehrenberg, 1854, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 238.

Dictyocha diommata, Ehrenberg, 1854, Mikrogeol., Taf. xxxiii., Nr. xvii. fig. 6.

Dictyocha erebi, Ehrenberg, 1854, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 238.

Dictyocha haliomma, Ehrenberg, 1844, Mikrogeol., 1854. Taf. xxi. fig. 46.

Dictyocha hexathyra, Ehrenberg, 1844, Mikrogeol., 1854, Taf. xxii. fig. 46.

Dictyocha ubera, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 80.

Dictyocha stella, Ehrenberg, 1854, Mikrogeol., Taf. xxii. fig. 52.

Dictyocha rotundus, Stöhr, 1880, Palæontogr., vol. xxvi., Taf. vii. fig. 9.

Each pileated piece of the skeleton is a truncated, six-sided pyramid, and composed of two regular hexagonal rings which lie in parallel plains, and are connected by six ascending interradial beams; these start from the corners of the upper smaller ring and bisect the sides of the lower larger ring; from the corners of the latter start six perradial centrifugal spines.

Dimensions.—Diameter of the basal ring 0.03, of the apical ring 0.01.

Habitat.—Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific; fossil in Barbados, Sicily, &c.

7. Distephanus ornamentum, Haeckel.

Dictyocha ornamentum, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 80;  Mikrogeol., 1854, Taf. xxii. fig. 49.

Dictyocha binoculus, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 79;  Mikrogeol., 1854, Taf. xix. fig. 42.

Each pileated piece of the skeleton is a truncated, six-sided pyramid, similar to that of Distephanus speculum, but distinguished by six small (probably vertical) teeth, which start from the inside of the lower (larger) ring, on the sides of the ascending beams.

Dimensions.—Diameter of the basal ring 0.03, of the apical ring 0.015.

Habitat.—Fossil in Tertiary deposits of Sicily, Caltanisetta (Ehrenberg).

8. Distephanus aculeatus, Haeckel.

Dictyocha aculeata, Ehrenberg, 1839, Abhandl. d. k. preuss. Akad. d. Wiss. Berlin, p. 149;  Mikrogeol., 1854, Taf. xxii. Fig. 48, Taf. xix. fig. 40.

Dictyocha aculeata, Stöhr, 1880, Palæontogr., vol. xxvi. p. 120, Taf. vii. fig. 7.

Dictyocha bisternaria, Ehrenberg, 1844, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 201.

Each pileated piece of the skeleton is a truncated, six-sided pyramid, similar to that of Distephanus speculum, but distinguished by six small perradial, horizontal teeth, which start from the sides of the upper (smaller) ring.

Dimensions.—Diameter of the basal ring 0.02, of the apical ring 0.008.

Habitat.—Fossil in Tertiary deposits of the Mediterranean; plastic clay of Greece and Sicily; living in the Mediterranean and the Atlantic, Station 352, surface.