58 



0. BELLATULUM, n. sp. — Shell apparently below the medium size, very 

 gradually tapering ; section circular or very nearly so ; septa about eight 

 to the inch, where the diameter is eleven lines ; surface longitudinally 

 sulcated with narrow concave grooves and covered with minute transverse 

 and longitudinal striae which are equally distinct both in the grooves, and 

 on the ridgos between them, about twenty strias in one line. The casts 

 of the interior of the chamber of habitation exhibit a broad shallow concave 

 constriction close to the aperture. Siphuncle unknown. 



The best preserved specimen consists of the chamber of habitation and 

 the last four septa. Length 30 lines ; diameter at the aperture 12 lines ; 

 at the fourth septum, where broken oif 11 lines ; width of the constriction 

 near the aperture 7 lines ; depth of the same i of a Hne. There are about 

 50 longitudinal sulci of nearly equal width, the average being five sulci in 

 three lines or thereabout. The four septa occupy 6J lines in the length 

 of the fossil ; the chamber of habitation 24 lines. The section is not quite 

 circular, but broad ovate apparently owing to pressure. 



The second specimen is 41 lines in length with nine septa and the 

 chamber of habitation, which latter is 21 lines in length ; width of the 

 constriction 6 lines ; depth J of a line ; space occupied by the nine septa 

 16 lines. As the specimen is distorted by pressure the diameter cannot 

 be made out exactly, but it appears to be about 12i^ lines at the aperture, 

 and 10 lines at the ninth septum, thus tapering at the rate of one line to 

 the inch. There are 34 sulci, but as the shell is not preserved the surface 

 markings cannot be determined. This specimen differs from the former 

 in having wider sulci and consequently fewer of them, but in other respects 

 appears to be specifically identical. 



It is possible that this may be 0. virigatum, Sowerby, now referred to 

 0. angulatum, Wahlenberg, by European authors. According to McCoy 

 the English specimens taper at the rate of 2h lines to the inch. Should it 

 turn out that the two specimens above described belong to distinct species 

 I desire that the first, as it shows the surface marking, may be accepted 

 as the type. 



Three miles east of Challoupe River ; Div. 3, A. G. J. Richardson. 



0. FORMOSUM, B., op. cit. p. 317. Junction Cliff ; Div. 1, A. G. Also 

 in H. R. 



0. Sedgwicki, B., op. cit., p. 320. Junction Cliff; Div. 1, A. G. 

 Also in H. R. 



0. SiEBOLDi, B., Gamache Bay ; Div. 1, A. G. Also in H. R. 



0. PiLEOLUM, n. sp. — Shell small, short, conical, expanding to a dia- 

 meter of twelve lines in a length of eighteen ; surface apparently smooth, 

 but on close examination covered with fine obscure engirdling striae. The 



