New ami Rare Fossils. 317 



Farii. UMBONIIDAE. 

 Genus TEINOSTOMA, H. and A. Adams. 



Teinostoma oepressula, sp. nov. (PI. XXVII., Figs. 24«, b). 



Description. — Shell depressed convex; on apical face sutures 

 flush with surface. Periphery rounded. Umbilicus filled in with 

 a callus, but the area is distinctly concave. Aperture subovate. 

 Surface polished, and under a high power finely striated with 

 growth-lines. 



Dimensions. — Greatest diameter, 1.84 mm. ; height, .75 mm. 



Observations. — The above species occurs in three samples of 

 strata in Bore No. 10, all of which contain a Kalimnan fauna, 

 and therefore the horizon of the species is definitely known. 



Distribution.— ^OYQ 10, 186-190 feet; 195-225 feet; 225-250 

 feet. 



Trinostoma pulcherrima, sp. nov. (PI. XXVII., Fig.s. 25«c). 



Description. — Apical aspect naticoid, depressed; whorls rapidly 

 widening, consisting of three coils. Lower side depressed, and 

 concave in the umbilical area ; umbilicus only partially filled with 

 callus. Surface marked with fine, but definitely incised growth- 

 lines, which under a high power are seen to be crossed by fine 

 sulcate markings, giving the surface a highly ornate appearance. 

 Aperture sub-quadrate. 



Dimensions. — Greatest diameter, 4.75 nmi. Height, 1.75 mm. 



Observations. — The above species is an aberrant form of Teino- 

 stoma. and on account of the partially open umbilicus might 

 eventually find a place in Cossmann's genus Bonnetla.^ 



A second specimen was found in the Ixn'ings in tliL' Mallt't-. hut 

 not figured. It belongs to the same specific type, but shows a slight 

 variation in liaving the' sutures of the whorls on the aj)ical side 

 more excavate and the whorls themselves less rapidly increasing in 

 width. The surface ornament is identical, whilst the aj)ertui-e 

 is of the same general form, but morr CDundly ovate, owing to the 

 narrower terminal whorl, and the uinl)iiicus is slightly nioi-e open. 



Affinities. — There appear to be no fossil or living i-epresenta- 

 tives of this form of shell closely appioaching it in all chaiacters. 

 perhaps the nearest being the living Teinostoma orhitinn. Hedley,- 



1. Aiuiales Soc. Roy. Zool. et Malac. Belg., vol. .\li., 1906, p. 207. (Genotype figiiieii on \>\. ix., 

 fiff. 16 ter-1). 



i. I'roc. Linn. Soc. X. S. Wales, vol. xw., I9uti, pt. i., p. 96, fiys. It 1.=.. 



