ART. 3 NEW SPECIES OF FORAMINIFERA VAUGHAN 5 



DESCRIPTION OF SPECIES 



DISCOCYCLINA WEAVERI, new species 



Plate 1, figures 1, 2 



Test small, lenticular, papillate, especially over its central part. 

 Diameter, 2.5 to 3 mm.; thickness, 0.9 to 1.1 mm., that is, about one- 

 third the diameter. The center is rounded, gently domed, with sides 

 sloping to the periphery. A large papilla over the center is about 

 140^1 thick, and around it are about 15 radiating plates. The 

 distance from this papilla to a surrounding circle of papillae is about 

 120/i. The outer papillae are smaller than those on the central 

 dome, but they are present virtually to the edge of the test. 



The embrj^onic apparatus consists of an initial chamber, 150m in 

 diameter, embraced by a second larger chamber, to the inner side of 

 the wall of which the initial chamber is attached. The embryonic 

 apparatus is similar to that of Eulepidina. The distance across the 

 two chambers is about 200/x. The wall of the initial chamber is not 

 well enough preserved to show the detail of its features. The wall 

 of the second chamber is perforate and about lOju thick. Outside 

 the embryonic apparatus proper there is an almost complete cycle of 

 chambers that have straight parallel sides and a slightly curved 

 perforate outer wall. About eleven of these chambers were counted, 

 and it is possible that they form a complete circle, but they were 

 not recognized in an arc opposite the attachment of the initial 

 chamber. The largest of these chambers has a radial diameter of 

 60m, including the thicknesses of both bounding walls, and a transverse 

 diameter of about 90^. The smallest has a radial diameter of about 

 55m and a transverse diameter of about 40^- (For further detail, 

 see description of a horizontal section of a variant, p. 6.) 



The equatorial chambers are arranged in annuli, the sides are 

 straight and parallel, and the ends are either straight or very slightly 

 curved, but such curvature is not sufficent to prevent the formation 

 of an annular wall. The chambers are usually only slightly elongate, 

 almost square in horizontal section. The length, measured radially, 

 is usually about 50m; the transverse diameter ranges from 25m to 

 40m. The transverse diameter of some chambers exceeds the length. 

 There is no appreciable increase in size toward the periphery. The 

 radial walls of chambers in adjacent annuli usually alternate in 

 position, but they are occasionally in alignment. The height of the 

 chambers in a vertical section of a megalospheric individual ranges 

 from about 25m near the center to about 40m near the periphery. 

 The perforations of roofs and floors range from about 2m to about 4m 

 across. 



The lateral chambers in a vertical section have thick roofs, small 

 cavities, and rather definite ends. There are about 10 layers, prob- 

 ably a few more, on one side of the equatorial layer over the center. 



