FOKAMINIFERA OF THE ATLANTIC OCEAN 31 



"There is no doubt that Williamson was familiar with this form, 

 but he failed to separate it from his Rotalina nitida, the description 

 of which, as we have already pointed out under that form, appears 

 to have been based on a series of allied specimens. He states that 

 *in some instances the inferior umbilicus is occupied by a distinct 

 and prominent umbo.' These specimens were, no doubt, our D. 

 praegeri. We have never seen any specimens of D. nitida presenting 

 this feature, the nearest approach to it being the presence of a small 

 tooth on each chamber projecting into the umbilical depression. By 

 the coalescence of these teeth and a raising of the height of the spire, 

 D. nitida passes into D. praegeri. 



"We have much pleasure in associating this form with the name of 

 Mr. R. Lloyd Praeger, but for whose perseverance and energy the 

 authors would not have been induced to undertake and carry through 

 their somewhat laborious task in connexion with the Clare Island 

 Survey." 



The above paragraphs and the figures are from the original paper 

 of Heron- Allen and Earland. The form is somewhat of an anomaly 

 with its ventral umbo and somewhat evolute test on the ventral side. 

 The distribution as given is a peculiar one from the British Isles, 

 Mediterranean, tropical shallow water of the Kerimba Archipelago 

 of the Southeastern coast of Africa, and the cold water of the Antarc- 

 tic. Such a distribution is indicated by Heron-Allen and Earland 

 for many of their species of the Clare Island paper, including often 

 shaDow water tropical material from Lord Howe Island in the Pacific. 

 Such a series probably indicates a very wide latitude in the definition 

 of the various species. 



"DISCORBINA ROSACEA (d'Orbigny)" 



Under this name there are a great many records from the Atlantic 

 and other regions. It has been a favorite "dumping ground" for 

 numerous Discorbis-like forms. Of the many records for ''Dis- 

 corbina rosacea," there are very few which figure the species and 

 practically none of these can be referred to the same species. d'Or- 

 bigny's "Rotalia rosacea" is from the Miocene of the Bordeaux 

 region well represented by Model No. 39. It is very clearly an 

 Amphistegina of the less complex type. I have abundant specimens 

 of this species from several localities in the Bordeaux region through 

 the kindness of Prof. G. Dollfuss, and they are uniformly a rather 

 high-spired Amphistegina. The structure is rather too complex to 

 place them in Asterigerina as was done later by d'Orbigny, although 

 they show well the transition from one of these genera to the other. 



It becomes impossible to use this species name for any of the many 

 forms of Discorbis called by various authors ''rosacea" and the 

 problem of straightening out the various species involved can only 



