Messrs. Carpenter and Brady on Parkeria and Loftusia. 461 



being of very subordinate value, and who had, on this basis, in- 

 dependently worked out a Systematic Arrangement of the entire 

 group, which presents a most remarkable correspondence with that 

 propounded by Dr. Carpenter and bis coadjutors. And their an- 

 ticipation of important ailditions to the Arenaceous series lias been 

 fully borne out, on the one hand by the discovery of several most 

 remarkable new forms at present existing at great depths in the 

 Ocean, which has been made by the dredgings of M. Sars, Jun,, and 

 those of the 'Lightning' Expedition, and on the other by the de- 

 termination of the real characters of two fossils, one of the Cretaceous, 

 and the other probably of the earlier Tertiary period, which prove 

 to be gigantic examples of the same type. 



The first of these, discovered by Prof. Morris more than twenty 

 years ago in the Upper Greensand near Cambridge, was long sup- 

 posed to be a Sponge ; but his more recent discovery of two speci- 

 mens which had been but little changed by fossilization, led him to 

 suspect their Foraminiferal character ; and this suspicion has been 

 fully confirmed by the careful examination made of their structure 

 by Dr. Carpenter, to whom he committed the inquiry, and by whom 

 with his concurrence, the name Parkeria was assigned to the genus. 

 The second, which was obtained by the late Mr. W. K. Loftus from 

 "a hard rock of blue marly limestone" between the X.E. corner 

 of the Persian Gulf and Ispahan, bears so strong a resemblance in 

 its general form and mode of increase to the genus Alveolina, that its 

 Foraminiferal character was from the first recognized by the dis- 

 coverer ; but as all the specimens brought by Mr. Loftus had under- 

 gone considerable alteration by fossihzation, their minute structure 

 though carefully studied by means of transparent sections, could not 

 in the first instance be satisfactorily made out. When, however 

 Dr. Carpenter's investigation of Parkeria, with the full advantage of 

 specimens but little changed by fossilization, revealed the very re- 

 markable plan of its structure, the investigation of this type was re- 

 sumed by Mr. Brady (who assigned to it the name Loftusia), with 

 the new light thence derived : for as transparent sections of infiltrated 

 ParJcerics furnish a middle term of comparison between specimens 

 of the same type v^hich retain their original character, and trans- 

 parent sections of infiltrated Loftusice, the last-mentioned can now 

 be interpreted by reference to the preceding ; so that the obscurities 

 which previously hung over their minute structure have been almost 

 entirely dissipated. — The descrii)tion of the structure of Parkeria in 

 this Memoir is by Dr. Carpenter, and that of the structure oi Loftusia 

 by Mr. H. B. Brady ; but each has gone over the work of the other, 

 and can testify to its correctness. 



The specimens of Parkeria which have been collected bv Prof. 

 Morris* are spheres varying in diameter from about 3-lth's of an 



* Since this Memoir was completed, the Author has learned tliat Mr. Ilarrv 

 Seeley, of Camhridge, has collected several specimens of this type, and has heeli 

 studying it independently with a view to publication. And NIr. Henry M'ood- 

 ward has placed in his hands a specimen from the Upper Greensand in the Isle 



