492 It. Bullen Netvton — Fossils from Singapore. 



reference as one of the species found in the Singapore Clays. This 

 specimen may be also said to resemble some small forms of 

 Unicardium. 



Dimensions. — Length 11. height 10 mm. 



Collector. — Mr. J. B. Scrivener. 



ASTAKTK SCRIVENORI, Sp. nOV. (PI. XXV, FigS. 11, 12.) 



Shell subquadrate, slightly convex ; umbo anterior ; dorsal line 

 slightly oblique; posterior area depressed, sloping, and angulated 

 below ; ventral margin nearly parallel with dorsal ; anterior area 

 rounded and short. Ornament consisting of from 10-12 nearly 

 horizontal costal ribs, obtusely angled on both sides, and separated 

 b}' rather wide sulcations ; anterior costce crowded and finest in front. 



Dimensions. — Fig. 11, length 14, height 11mm.; Fig. 12, length 

 11, height 7 mm. 



This form is represented by two right valves of different ages, 

 the younger showing a mucli finer and more crowded system of 

 costse (Fig. 12), whilst the older shell (Fig. 11) possesses a bolder 

 and coarser sculpture. The lateral angles of the costse present 

 a feature of interest in the sculpture which is apparently not known 

 among typical astartiforra shells, hence it has been regarded as 

 a new species. In addition it may be mentioned that this species 

 shows a certain resemblance in contour and structure to A. inter- 

 lineata of Lycett, from the Great Oolite of Minchinhampton (see 

 Mon. Pal. Soc, 1854, pi. ix, figs. 14, 15, p. 87). 



Collector. — Mr. J. B. Scrivenor. 



ASTARTK GUTHRIENSIS, sp. UOV. (PI. XXV, Fig. 9.) 



Shell small, subelliptical, moderately convex; umbo anterior; 

 front area short, rounded, slightly excavated beneath the umbo ; 

 posterior margin elongate, oblique ; ventral border thickened, 

 rounded; sculpture consisting of about 10 wide, elevated, concentric 

 costas, bearing minute lineations, divided by smooth sulcations of 

 nearly equal width. 



Dimensions. — Length 11, height 6 mm. 



This specimen is embedded in the matrix and exhibits an external 

 view of the right valve. The dorso-posterior margin is rather 

 imperfect, otherwise the specimen is fairly seen and its ornamentation 

 is well displayed. The raised concentric and striated ridges 

 divided by the prominent smooth sulcations and without any 

 evidence of radial lines, are the chief sculpture characters of the 

 valve. 



Collector. — Mr. J. B. Scrivenor. 



AsTARTE GuTHRiENSis, var. nov. (PI. XXV, Fig. 10.) 



Shell with similar sculpture to A. Gufhriensis, but of rather 

 quadrate form, and considerably less oblique posteriorly. 



Dimensions. — Length 10, height 7 mm. 



This variety is represented by an external surface of a right valve 

 in which the umbo is not preserved, but the excavation beneath is 

 well marked. 



Collector. — Mr. J. B. Scrivenor. 



