Manchester Memoirs, Vol. Ixii. (191 7) 129 



"The little stalk-like projections from the chambers are, in 

 the fully grown specimens, broken off at the commencement. 

 Only a few young examples possess these projections of a fairly 

 even length. I could not determine the position of the aper- 

 ture with any certainty, in any of the examples. 



"The name Siderolina I cannot hold correct. Siderolina 

 should be identical with Siderolites (as Nummulina and A urn 

 mulites), but Siderolina (S. kochi (Hantken) understood. H-A & 

 E.) is something quite different. The foregoing form belongs 

 rather to Pullenia, or in the neighbourhood of the almost piano- 

 spiral compressed Globigerince , whose chambers are arranged 

 similarly to G. digitata." 



Liebus figures the species both as an opaque object and in 

 section and his drawings show a thick-walled finely perforate 

 involute test with five chambers visible externally. The two 

 final chambers extend forward at a tangent, and terminate m a 

 large tubular opening. There is no suggestion of a spinous 

 termination but the extensions are evidently broken. If the 

 tubes originally terminated in a perforated spine as in the 

 Biarritz specimens, they must have been enormously prolonged. 

 One other chamber shows a similar perforate process on a 

 minute scale, but the first and third chambers have an unbroken 

 and symmetrical surface. 



We are not satisfied with the allocation of the species to 

 Pullenia. Its affinities are undoubtedly rbscure, but the texture 

 of the shell-wall appears to us to have little in common with 

 Pullenia, and nothing but the external form is comparable with 

 Globigerina digitata Brady, which has a characteristically 

 globigerine wall. The texture of the wall in the Biarritz 

 specimens strongly suggests Nonionina, although the presence 

 of the perforate spines is quite alien to that genus. This feature 

 indeed may render it necessary to institute a new genus for the 

 specimens, whenever a further supply of material renders 

 additional investigations into their structure possible. It is 

 possible that the species may be found to be allied to the some- 

 what similar, but more minute organism described by bchackn 

 under the name Siderolina cenomana. * For the present we 

 prefer to record the Biarritz specimens as Nonionina kochi 

 (Hantken), and to supplement the previously published remarks 

 of Hantken and Liebus with the following note : — 



Test free, involute, consisting of two or more convolutions 

 of chambers rapidly increasing in size, armed in the later cham- 



* Schacko. Foram. aus d. Cenomankreide von Moltzow i. Meckl.-Arch. d. 

 Ver. d. Freunded. Naturgesch, i. Meckl. vol. L. 1896, p. 166, figs. 3-5. Videa\so: — 

 Siderolina cenomana, Schacko, in Egger, 1899 Foram. Kreidem. d. Oberbay. Alpen. 

 Abh. k. bayer. Ak. Wiss. CI. II. vol. XXI. pt. 1, p. 174, pi. XXI, fig. 42. 



