1 68 NEW YORK STATE MUSEUM 



There can be no mistaking this almost globular form of Lagena, 

 though it varies considerably in size, in amount of aperture and 

 neck elongation, and in the more oval and elongate type merges 

 into L . 1 a e V i s . The flattened forms become L. laevigata, 

 while similar roughened-surface types constitute L . a s p e r a 

 and costate forms L . sulcata, all of which are modifications 

 of this simple rounded Lagena. As Professor Brady points out, 

 Lagenae, contrary to expectation, are not very common in Pre- 

 carboniferous formations; but we would expect them to be more 

 numerous in lower Paleozoic strata than any of the more complex 

 types. We believe that their absence can be partly accounted for 

 because of their delicate, thin shells and minute size, so that they 

 are not so readily preserved as larger and often more arenaceous 

 Foraminifera. According to Brady (loc. cit.), the only notices of 

 Precarboniferous Lagenae published prior to 1888 occur in T. Rupert 

 Jones's list of Upper Silurian Microzoa given in the Geological 

 Magazine for February 188 1. 



The largest Silurian specimens figured by Brady were 2 mm in 

 diameter, which is much larger than most recent specimens. The 

 species occurs on slide 6, measuring 0.12 mm to 0.15 mm in diameter. 



Lagena laevis (Montagu) 



Plate 3, figures lO, ii 



Vermiculum laeve, Montagu, 1803, Test. Brit., p. 524 

 Lagena laevis, Bagg, 1912, U. S. Geol. Survey Bui., p. 48, pi xiii, 

 figs. 5-8, K, 10, II, a, b, pi xiv, figs. 23, 24 



The unicellular, oval-chambered, smooth Lagena, known as 

 Lagena laevis, is a small, elongated oval form with the apical 

 end more or less prolonged, but not so strongly so as in L a g e n a 

 clavata or Lagena gracilis. It closely resembles the 

 narrower forms of Lagena globosa; but . the length is 

 approximately double the width, one of the two forms found meas- 

 uring approximately 0.05 mm in width and o.io mm in length, 

 though we can not be sure that this includes the full aperture exten- 

 sion of the original form. 



There are two of these minute fossil Lagenae on slide 6 (also 

 found on slide 2). The species is known in the Upper Silurian 

 at the base of the Wenlock series in the Woolhope limestone from 

 Wych, Malvern, England. Unless the original flanged neck of 

 these English specimens has been lost in silicifi. cation, they were 

 probably without such ornamentation. The short aperture exten- 



