MILIOLIDAE 51 



32. Cornuspira diffusa, Heron-Allen and Earland (Plate I, figs. 5-7). 



Cornuspira foliacea, Brady, 1884, FC, pi. xi, fig. 7 (monstrous specimen, no ref. in text). 



Cornuspira foliacea, Rhumbler, 1903, ZRR, p. 287, fig. 141 b. 



Cornuspira diffusa, Heron-Allen and Earland, 1912, etc., NSG, 1913, pp. 272-6, pi. xii; CI, 



1913. P- 37; FWS, 1916, p. 217. 



Cornuspirella diffusa, Cushman, 1918, etc., FAO, 1929, p. 85, pi. xxi, figs. 6, 7. 



Two stations: 149; MS 68. 



Many characteristic fragments at each station. 



Genus Gordiospira, Heron-Allen and Earland, 1932. 



Test free, porcellanous, very thin-walled and fragile, approximately circular in shape, 

 consisting of a proloculum around which a non-septate tubular chamber forms several 

 coils in different planes, finally becoming planospiral, and involute for several con- 

 volutions. In the planospiral stage the tube rapidly expands in width and thickness. The 

 umbilical area is depressed and exhibits the edges of some of the earliest convolutions. 

 Aperture large and terminal. 



Gordiospira is isomorphous with Glomospiro, Rzehak (1885), but the irregular con- 

 volutions of the initial coil are less visible externally. They become very evident in 

 transparent preparations. 



33. Gordiospira fragilis, Heron-Allen and Earland (Plate VI, figs. 10-15). 

 Gordiospira fragilis, Heron-Allen and Earland, 1929, etc., FSA, 1932, p. 254, pi. i, figs. 1-6. 



Six stations: 45, 144, 145, 149; WS 33; MS 68. 



Test free, porcellanous, oval when young, becoming circular with full growth, very 

 thin and fragile, papery white or translucent, surface often irregular and marked with 

 recurved lines of growth. Viewed as an opaque object, it exhibits 2-3 planospiral and 

 embracing whorls of a tube, which increases in diameter and thickness so rapidly that 

 the final convolution forms the bulk of the entire test. The central portion of the test is 

 depressed, and shows one or two transverse tubes. The aperture is terminal, very 

 large, the outer margin projecting, the inner margins recurved to join the previous 

 whorl. 



Viewed as a transparent object, Gordiospira fragilis is seen to consist of a proloculum 

 around which an unseptate tube is irregularly coiled in 3-5 convolutions set in different 

 planes. Subsequently, the tube becomes planospiral, forming 2-3 convolutions rapidly 

 increasing in size and thickness. These later convolutions are involute to some extent, 

 each concealing at least half of the previous convolution. 



The surface of the tubes is often rather irregular and always exhibits faint recurved 

 lines of growth. 



Both megalospheric and microspheric forms have been identified, the latter being the 

 larger, as usual. The megalospheric proloculum is about 0-02 mm. in diameter, the 

 microspheric too small to be measured with certainty. The size of the test ranges up to 

 1-5 mm. or rather more, in diameter, but the general average is under i-o mm. 



