146 



LiNEARIA SUCIENSIS. (N. Sp.) 

 Plate 17, figure 12. 



Compare Tellina strigata, Goldfuss. — Petrefacta Germanije, Vol.11., p. 235, pi. 147, figs, 



18rt, b. 



Shell compressed-convex, nearly equilateral, transversely subelliptical, 

 length about one-third greater than the height, test rather thin. 

 Anterior side narrowly rounded, posterior side a little longer than the 

 anterior, subtruncated nearly vertically at the end, but most prominent 

 above, and subangular at its junction with the ventral mai-gin below ; 

 posterior area flattened obliquely, but without any distinct umbonal 

 ridge ; base nearly straight in the middle, but rounding upwards at each 

 extremity. Beaks small, rather broad, but not prominent nor elevated, 

 placed a little in advance of the middle and pointing distinctly forwards. 

 Dorsal margin sloping very gently and somewhat convexly downwards in 

 both directions, but slightly concave immediately under the beaks in 

 front. 



Surface marked by extremely fine, crowded, concentric striae, and by 

 radiating impressed Hnes. The latter are most strongly marked on the 

 upper half of the shell, and become nearly obsolete before reaching the 

 venti-al margin. On the upper slopes of both extremities, especially on 

 the posterior area, the radiating impressed lines are comparatively broad, 

 80 much so as to give to these declivities a finely ribbed aspect to the 

 naked eye^ but on the central area of the valves the impressed lines are 

 very narrow and not visible without the use of a lens. 

 Hinge teeth and muscular impressions unknown. 

 Length, about eleven lines and a quarter ; height, seven lines. 

 Sucia Islands, in Division A; J. Eichardson, 1875. One right valve. 

 A very interesting little shell, whose external characters seem to be 

 intermediate between those of Palceomcsra, Stoliczka, and Linearia, 

 Conrad. Its shape and surface ornamentation, both of which are very 

 peculiar, are so like those of Tellina strigata. Goldfuss (the type of 

 Pakeomcera), that it may be only a variety of that species. The most 

 appreciable difference between the two shells is that the beaks of L. 

 Suciensis are placed very slightly in front of the middle, whereas those 

 of T. strigata are situated a little behind the centre. 



Tellina (^Linearia) sculptilis of Stoliczka, from the Cretaceous rocks of 

 Southern India, is also very nearly allied to the present species, and may 

 perhaps be identical with it, but the beaks of the Indian shell are 



