NO. lO AMERICAN SPECIES OF LEPIDOCYCLINA — VAUGHAN I9 



This variety differs from typical L. parviila in possessing well- 

 developed costae. When viewed in the vertical section, the pillars 

 are much heavier than in L. parvula, and the lateral chambers are 

 more crowded and not so well developed. However, this form may be 

 connected with the typical parvula through such forms as are illus- 

 trated on plate 10, figure 6. These specimens show increase in size of 

 the papillae and, coincidentally, reduction in their number to six 

 radially arranged large papillae or costules. There may or may not be 

 a central papilla or boss. 



The next stage apparently is the form that we are describing as 

 the new variety, var. crassicosta, illustrated by plate lo, figure 7. 

 This specimen has had its encircling rim broken off, but other speci- 

 mens in the collection have the rim well developed. Although the 

 series of L. parvula is practically unbroken from the forms with 

 many small papillae to the forms with a few large papillae, var. 

 crassicosta is so extreme that it is distinguishable from the more 

 usual variants of the species. 



LEPIDOCYCLINA ANTIGUENSIS Vaughan and Cole, n. sp. 

 Plate 10, fig. 8; plate 24, figs. 2, 3 



Test small, compressed, lenticular, with a marginal rim about 

 0.30 mm wide ; outline faintly polygonal ; diameter 3.0 mm ; thickness 

 i.o mm. Apical area with a series of large papillae which are about 

 0.20 mm in diameter. Two or more of the papillae are enclosed by 

 about nine other papillae, which form a circle 0.75 mm in diameter 

 over the central part of the test. From this area the test slopes 

 gradually to the marginal rim. The slope is ornamented by about 1 1 

 costae which grade into the papillae at the outer edge of the apical 

 area. Toward the periphery the costae broaden rapidly, but become 

 lower as they approach the rim where they are faint or obsolete. 

 Some costae bifurcate, others remain single. The rim is narrow, flat, 

 and without ornamentation except slight traces of the costae. The 

 entire surface of the test, except on the papillae, shows faint reticula- 

 tions which become more pronounced on the rim. 



In equatorial sections the equatorial chambers near the center are 

 lozenge-shaped ; toward the periphery they range in shape from short- 

 spatulate to rudely hexagonal. Chambers near the center have a radial 

 diameter of about 40 /* and a transverse diameter of about 50 /a ; those 

 near the periphery have a radial diameter of about 50 /t and a trans- 

 verse diameter of about 45 p.. 



