94 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



siliferous limy sandstone collected by MacDonald at station No. 

 6255 from half a mile south of Miraflores Station on the wagon road 

 to Panama. 



LEPIDOCYCLINA MACDQNALDI, new species. 



Plate 40, figs. 1-6. 



Test circular, rather small, about 5 to 7 millimeters in diameter, 

 thickest in the central region, thence gradually sloping to the 

 periphery which for a short distance in from the edge is nearly flat ; 

 wall rather smooth except the central portion of the umbonal region, 

 which has a few pustule-like raised spots at the surface end of the 

 vertical pillars. 



Vertical section shows the test widest in the middle, gently sloping 

 to near the periphery where the edges are nearly parallel for a short 

 distance to the peripheral edge or even slightly increasing in thick- 

 ness. Lateral chambers in the central portion in definite vertical 

 columns, occasionally slightly overlapping. Equatorial chambers 

 not increasing very rapidly in height in megalospheric specimens, 

 those at the periphery hardly more than double the height of those 

 near the center of the test ; embryonic chambers in the megalospheric 

 form, large, usually of two nearly equal chambers, but in oblique cut- 

 ting these may appear somewhat unequal, plate 40, figures 2 and 3. 



Horizontal sections show chambers somewhat similar to L. 

 vaughani but with the inner half of two walls at nearly right angles, 

 the outer wall broadly rounded. The oblique section (pi. 40, fig. 6) 

 shows the pillars. 



Occurrence. — Type-specimens from station 6523, from orbitoidal 

 limestone, 2 miles north of David, Panama, collected by D. F. Mac- 

 Donald, U. S. National Museum Catalogue No. 324740. Specimens 

 were abundant at this station, occurring with L. panamensis and L. 

 duplicata. The species were also collected by MacDonald at station 

 6512, in the river bed at David. 



LEPIDOCYCLINA PANAMENSIS, new species. 



Plate 39, figs. 1-6 ; plate 42. 



Test circular, small, central portion very strongly umbonate, thick, 

 rapidly decreasing in thickness peripherally, the peripheral portion 

 thin and flattened, the raised central portion only one-third to one- 

 fifth the entire diameter, which ranges from three to six millimeters ; 

 occasional specimens, perhaps representing the microspheric form, 

 up to 10 or 12 millimeters in diameter; surface smooth except for 

 the unbonal portion which has a few large pustule-like projections 

 marking the ends of the internal pillars. 



