1. Lithobotrys geminata, Ehrenberg.
Lithobotrys geminata, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi, p. 519, Taf. xxxiii. fig. 27, a to c.
? Lithocorythium platylophus, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. iv. fig. 5.Cephalis trilobate, with a single apical tube in the apex of the helmet-shaped occipital lobe, which is one and a half times as long as the two subspherical frontal lobes. Thorax ovate, one and a half times as long as the cephalis, with few small pores in six to eight transverse rows.
Dimensions.—Length of the shell 0.1, breadth 0.05.
Habitat.—Fossil in Barbados.
2. Lithobotrys lithocorythium, Haeckel.
Cephalis trilobate, with a single apical horn or a pointed tube in the apex of the helmet-shaped occipital lobe, which is a little longer than the two ovate frontal lobes. Thorax ovate, about as long as the cephalis, with very numerous and small pores.
Dimensions.—Length of the shell 0.08, breadth 0.04.
Habitat.—Fossil in Barbados.
3. Lithobotrys nasuta, Ehrenberg.
Cephalis quadrilobate, with a single descending sternal or nasal tube on the base of the anterior or frontal lobe, which is half as long as the helmet-shaped occipital lobe and twice as large as the two lateral buccal lobes. Thorax ovate, twice as long as the cephalis. Pores rather large, circular.
Dimensions.—Length of the shell 0.11, broad 0.05.
Habitat.—Fossil in Barbados.
4. Lithobotrys ornata, Ehrenberg.
Cephalis quinquelobate, with two divergent ascending tubes, a posterior occipital and an anterior sternal or nasal tube. Occipital lobe campanulate, twice as large as the two frontal, and four times as large as the two buccal lobes. Thorax ovate, twice as long as the cephalis. Pores scarce and small. The specimen figured by Ehrenberg is very incomplete.
Dimensions.—Length of the shell 0.09, breadth 0.05.
Habitat.—Fossil in Barbados.
