Dimensions.—Longer axis of the shell 0.12, shorter axis 0.09; pores and bars 0.004 to 0.006; length of the polar spines—longer 0.12, shorter 0.06.
Habitat.—Fossil in Barbados.
4. Lithomespilus flammabundus, n. sp. (Pl. [14], fig. 14).
Proportion of the major axis to the minor = 4 : 3. Shell thin walled, with irregular, roundish pores, partly simple, partly composed of three to six confluent pores; only six to eight pores on the half equator, twice to four times as broad as the bars. Surface spiny. Length of the conical irregular spines increasing towards the poles; each polar spine surrounded by a flame-shaped, circumpolar area of longer spines; all large spines (also the polar spines) curved or contorted at one pole and much stronger and more numerous than at the other; length variable, often equal to the longer axis.
Dimensions.—Longer axis of the shell 0.12, shorter axis 0.09; pores 0.005 to 0.015, bars 0.003 to 0.005; length of the polar spines 0.1 to 0.15.
Habitat.—Western part of the Tropical Atlantic, Station 347, depth 2250 fathoms.
Genus 129. Lithapium,[[168]] n. gen.
Definition.—Ellipsida with simple ellipsoidal or pear-shaped shell; with a single spine only situated at one pole of the main axis.
The genus Lithapium represents a peculiar modification of Ellipsoxiphus; one of the two opposite polar spines disappears by reduction, and in this way only a single spine remains, at one pole of the main axis. For this reason the shell assumes a characteristic pear-shape, and may easily be confounded with some similar Monocyrtida (Halicapsa).
1. Lithapium pyriforme, n. sp. (Pl. [14], fig. 9).