686 MESSES. E. HEEOA^'-ALLEN AND A. EAELAND ON THE 



edge thick and subcarinate. Aperture obscure, if existent at all. Inferior surface 

 plane, studded with tubercular growth either in the form of round or oval beads, 

 rendering the number of convolutions uncertain. The last convolution on the 

 inferior surface is usually free from secondary growth. The marginal view in 

 specimens where the superior surface is not embracing is very characteristic and 

 resembles an upstanding frill. 



A single specimen of this highly specialized form was found at Stn. 1 and many 

 at Stn. 11. We have met with the species at the ' Challenger ' Stn. 185 (Raine Island,, 

 Torres Straits, 155 fms.), and at other localities, and we have Eocene specimens 

 from Moorabool River, Victoria, N.S.W. Within certain limits it is subject to con- 

 siderable variation. In some specimens the last convolution entirely encloses all its 

 predecessors on the superior surface, leaving merely a central pin-hole, as it were, to 

 mark the axis of convolution. In other instances, where the tube is convoluted at 

 a less acute angle, the embracing character of the whorls is less marked, and the 

 sharp superior edge of the tube can be seen in a diminishing spiral lining the sides 

 of the central depression. The nature of the tubercular growth on the inferior 

 surface appears to change from spherical to oval beads with the increasing diameter 

 of the tube as the shell grows in size. The curiously plicate appearance of the 

 external surface of the tube is probably due to internal constrictions rather than to 

 merely external decoration, and may mark a transition-stage between Spirillina and 

 Patellina. If such be the case, the species would usefully support Ehumbler's 

 view, in which he is entirely supported by Schaudinn (S. 1895, PF. p. 181), that the 

 genus Patellina should properly be merged with the genus Sjnrillina (R. 1895, 

 NST. p. 85). 



Breadth of base 0"30 to 0"o5 mm. ; height variable, ranging up to O'l mm. 



Subfamily Eotaliin^. 

 Patellina Williamson. 



334. Patellina COrrugata Williamson. 



Patellina corrugata WiWiamson, 1858, RFGB. p. 46, pi. iii. figs. 86-89. 

 Brady, 1884, FC. p. 634, pi. Ixxxvi. figs. 1-7. 

 Egger, 1893, FG. p. 393, pi. xiv. figs. 70-72. 

 Schaudinn, 1895, PF. p. 181 (fig.). 

 Chapman, 1907, RFV. p. 134, pi. s. fig. 7. 

 Heron-Allen & Earlaud, 1913, CI. p. 109, pi. ix. fig. 11. 

 „ {Arpatellum dunst-corrugatum m. ! !) Rhumbler, 1909, etc., FPE. 1913, 

 pp. 409-413, figs. ; p. 437, pi. v. figs. 5-7 ; pi. vii. figs. 11-15. 



11 Stations. 



Very generally distributed, but the number of specimens always very limited, and 

 most of the individuals were of the normal depressed type. At Stns. 1 and 4 the 



