(93) Galveston Well Fossils ii 



RANGIA. 



Rangia cuneata var. galvestojiensis, nov. var. PL 2, fig's i, a, b. 

 Syn. Gnat/wdon {nearest cuueahis) Har., 4th Ann., p. 121. 



Variety galvestoncnsis differs from the typical form by having 

 a less angular outline, by being less carinated from the umbones 

 to the posterior termination, and by having the beaks less distant. 

 Some specimens, however, are very close to aineatus ; the teeth 

 in all are the same. 



Range 171 depth. — From 1,510 to 2,920 feet. 



Rangia? qiiadi'icentennialis , n. sp. PI. 2, fig's 2, a, b, c. 



-^ Syn. Gnathodon, n. sp., Har., 4th Ann., &c., 1893, P- 121. 

 Spisulaf quadricentennialis Dall, Proc. U. S Nat. Mus. 

 vol. 17, 1894, p. 105. 



Specific characterization. — Shell elliptical in outline as figured ; 

 thin ; surface nearly smooth, except on the broadly rounded um- 

 bonal ridge the concentric striae are more or less prominent in old 

 specimens ; a faint, broad sinus extends from beak to base ; teeth 

 of the right valve shown in fig. 2 a, those of the left in 2 c. Fig. 

 2 b represents the shell as it usually appears, the hinge plate being 

 nearly always broken away. 



Range in depth. — From 2,100 to 2,249 feet. 



Type. — Texas State Museum. 



MACTRA. 



Mactra late7^alis . 



Syn. M. /atera/is Say , Jr. Ac. Nat. Sci. Phila., vol. 2, 1822, 

 p. 309. 

 M. lateralis Har., 4th Ann. &c., p. 121. 



Range in depth. — From 300 to 2,920 feet. 

 Mactra quadricentennialis , n. sp. PI. 2, fig's 3, a, b. 



Syn. Mactra, n. sp., Har., 4th Ann. &c., p. 121. 



Specific characterization. — General form cuneate as figured ; 

 hinge as shown in fig's 3, 3b ; substance of the shell either thin 

 and showing but slight traces of muscular scars within, or slightly 

 thickened and showing the muscular scars and a small pallial si- 

 nus. A ridge extends from the umbones to the posterior margin ; 

 a less marked though observable ridge extends from the umbones 

 to the anterior margin. 



Range in depth. — From 2,236 to 2,871 feet. 



