Page:Scientific results HMS Challenger vol 18 part 2.djvu/608

1484 2. Lithomitra acephala, Bütschli.

Lithomitra acephala, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 529.

Eucyrtidium acephalum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. xi. fig. 5.

Eucyrtidium obstipum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. xi. fig. 17.

Shell nearly cylindrical, smooth, thick-walled, with twelve to sixteen subequal joints. On each joint a single row of small circular pores. No external strictures. Scarcely differing from the preceding species; the joints are broader and shorter, the cephalis is larger (by union of some joints?), and the ribs of the surface less distinct.

Dimensions.—Length of the shell (with twelve joints) 0.1; length of each joint 0.006 to 0.009, breadth 0.04.

Habitat.—Fossil in Barbados.

3. Lithomitra lineata, Haeckel.

Lithocampe lineata, Ehrenberg (partim), 1838, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 130; Mikrogeol., 1854, Taf. xxii. fig. 26.

Lithocampe lineata, Haeckel, 1862, Monogr. d. Radiol., p. 316.

Eucyrtidium lineatum, Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 43; Mikrogeol., 1854, Taf. xxxvi. fig. 16; Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 72, Taf. xi. fig. 9.

Dictyomitra lineata, Stöhr, 1880, Palæontogr., vol. xxvi. p. 101, Taf. iii. fig. 22.

Shell subcylindrical, smooth, with longitudinal ribs, and four to eight slight transverse strictures. Cephalis small, subspherical, with few small pores. Thorax broader, with two or three transverse rows of pores. Each succeeding (abdominal) joint with a single transverse row of small pores. Variable and nearly related to the two preceding species (compare my Monograph, loc. cit.).

Dimensions.—Length of the shell (with six to eight joints) 0.06 to 0.08; length of each joint (on an average) 0.01, breadth 0.03.

Habitat.—Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific, in various depths; many stations; fossil in Secondary and Tertiary rocks of many places.

4. Lithomitra nodosaria, n. sp. (Pl. 79, fig. 1).

Shell subcylindrical, with longitudinal ribs, and five to eight transverse strictures, and prominent girdles between them. On each girdle (at the lowermost edge of each joint) a single transverse row of circular pores. The three or four uppermost joints are united, and represent a conical cephalis.

Dimensions.—Length of the shell (with six joints) 0.1; length of each joint 0.01 to 0.15, breadth 0.04 to 0.06.

Habitat.—Central Pacific, Station 263 to 274, depth 2350 to 2925 fathoms.