Shell widely conical, with six to eight prominent strictures. All joints nearly equal in length, gradually increasing in breadth, the eighth five times as broad as long, and twice as broad as the third. In each joint three to four transverse rows of regular, hexagonal pores. (Similar to Lithostrobus hexagonalis, Pl. [79], fig. 20, but more slender, and without cephalic horn.)
Dimensions.—Length of the shell (with seven joints) 0.16, of each joint 0.022; breadth of the sixth 0.08.
Habitat.—South Pacific, Station 295, depth 1500 fathoms.
Subgenus 2. Dictyomitrissa, Haeckel.
Definition.—Shell smooth, with joints of very different lengths.
4. Dictyomitra polypora, Zittel.
Dictyomitra polypora, Zittel, 1876, Zeitschr. d. deutsch. geol. Gesellsch., p. 80, Taf. ii. fig. 1.
Shell slender, conical, rough, with six to nine deep strictures. Breadth and length of the joints gradually increasing, so that the eighth joint is twice as long and broad as the third. Pores regular, circular, in transverse rows, four rows in each joint, in the last joint five to six rows.
Dimensions.—Length of the shell (with eight joints) 0.24; length of the eighth joint 0.04, breadth 0.1; length of the third joint 0.02, breadth 0.05.
Habitat.—Fossil in secondary rocks of Northern Germany (chalk of Brunswick, &c.), Zittel.