346 PROCEEDINGS OF SECTION C. 



in no part of the world does it appear more at home than on some 

 of the Australian coasts. Messrs. Jones and Parker have figured 

 two species of Nuhecidaria from the Upper Triassic clays of 

 Chellaston, Derbyshire. It occurs sparingly in later .Mesozoic and 

 Tertiary formations of P]ngland and the Continent, and the author 

 has obtained about half a dozen small examples of A^. lucifuga 

 from the Carboniferous limestone shales of Northumberland (M.S.), 

 which is the lowest position in which it has been recorded in the 

 geological series. 



SPIROLOGULINA (?) PLANULATA (Lamk.). 



The transparent rock sections exhibit a few Spiroloculince^ cut at 

 various angles, and apparently all of the same species. One of 

 these can be seen on Plate X., near the central line and one- 

 fourth distance from the bottom, the line of section cutting the 

 object transversely nearly through the centre of the test. The 

 segments (about eleven in number) are narrow, of rounded contour, 

 increasing slowly in size with the growth ; the final chambers 

 enlarge suddenly, and on one side there is an apjjearance of a 

 carinate ridge running longitudinally along the exterior periphery. 

 No other example of SpirolocnUna in the sections exhibit the 

 carinate feature, and it may be only a defect in grinding the object. 

 It is impossible to determine the specific relationship of this form 

 with any certainty on the slender data at command. It somewhat 

 resembles (so iar as can be judged from the section) the neater 

 varieties of >S'. planulata, and to this species we have provisionally 

 referred it. Messrs. Parker and Jones have observed the presence 

 of this species in the Lower Lias of Warwickshire, which has 

 been, up to the present, the earliest geological record of the occur- 

 rence of the genus. 



(1) CORUNSPIRA INVOLVENS {^^v&s). 

 There are one or two very small planospiral shells that can be 

 recognised in the transparent slides. Considered morphologically 

 they may belong to one or other of three genera — Cormispira (in 

 which the shell is porcellaneous and imperforate), Spirallina (with 

 the test hyaline and perforate), or Ammodiscus (an arenaceous 

 foraminifer). The last-mentioned is a common form in the Car- 

 boniferous limestone of Europe, from which about eight species 

 have been determined. The analogous form in the Permo- 

 Carboniferous rocks of Tasmania is evidently calcareous in 

 structure, and must therefore be referred to one of the two former 

 genera. The minuteness of the objects and the infiltration of 

 mineral matter, to which they have been subjected, make it most 

 difficult to decide on the existence or absence of perforation in the 

 test. It is probable that, for similar reasons, great uncertainty 

 exists as to the distribution of these respective forms in a fossil 

 condition. They have not always been clearly distinguished by 



