Fauna of the Bud % Limestone 
15 
convex, geniculate, ornamented with eight strong, radiating 
costse, terminating in hollow, lamellar spines, at the genicula- 
tion. Below the geniculation, the surface is marked by heavy 
lines of growth, with only a trace of the costse. Right valve 
ornamented with five or more radiating costae extending to the 
margin and bearing four concentric rows of spines. 
The hinge and interior were unknown when, in my thesis, I 
described this shell as Plicatula geniculata n. sp. Recently, 
however, material has been gathered, indicating that it should 
be referred to the genus Anomia. 
Locality.- — Shoal Creek, Austin, Texas. 
MYTILIDAE 
Genus MODIOLA Lamarck. 
Modiola austinensis n. sp. 
PL II, hg. 6. 
Dimensions . — Length, about 40mm.; breadth, 18mm. 
Description. — Shell elongate, subcuneate, arcuate, inflated an- 
teriorly, compressed posteriorly; beaks subterminal, twisted for- 
ward; umbonal ridge prominent, sloping abruptly to the ante- 
rior; surface ornamented with concentric lines of growth, crossed 
by numerous fine striae radiating from the beak, and covering 
the entire shell. 
Locality. — Shoal Creek, Austin, Texas. 
PHOLODOMYACIDAE 
Genus HOMOMYA Agassiz. 
Homomya budaensis n. sp. 
PI. Ill, figs. 1, 2. PI. IV, figs. 1, 2. 
Dimensions . — Length about 110mm.; breadth, 60mm.; thick- 
ness 61mm. 
Description. — Shell large, globose, equivalved, inequilateral, 
greatly produced and broadened posteriorly; anterior margin 
short, curved; ventral margin deeply curved; posterior margin 
broadly rounded; dorsal margin curved, subparallel with ven- 
tral; umbos globose, approximate, elevated, curved inward and 
