462 Intelligence and Miscellaneous Articles* 



Greensand had been in part referred to the genera Scyphia and 

 Porospongia, and in part left unidentified. An examination of sec- 

 tions of these forms by the microscope had revealed all the details of 

 Yentriculite structure ; and a careful comparison with Mr. Toulmin 

 Smith's descriptions and specimens had resulted in the identification 

 of those examined with some four of Mr. Smith's species ; thus 

 Scyphia tessellata was shown to be equivalent to Ventriculites tessel- 

 latus (or, more correctly, V. texturatus), Porospongia ocellata to V. 

 cavatus, and other unnamed forms to V. quincuncialis and V. mam- 

 millaris respectively. The occurrence of ventriculite-structure 

 in coprolitic material presents a favourable opportunity for a fresh 

 inquiry into its nature ; accordingly the author described the minute 

 characters of the hexaradiate elements of which the skeleton is com- 

 posed, and the combinations of these hexradiates with one another. 

 Abnormalities occur sometimes by the hexaradiates becoming hepta- 

 radiate or pentaradiate, and sometimes by some of their rays bend- 

 ing quite away from their normal course. The whole of the skeleton 

 fibre is distinctly tubular. . Since the Yentriculite fibres have now 

 been found fossilized in chalk, flint, and calcic phosphate, there 

 can be little doubt that they were keratose, and not- siliceous in their 

 nature. If this be so, we have a difference between Yitrea and 

 Yentriculitidae of ordinal value at least, and we must look for allies 

 to the Yentriculites among the horny sponges. Verongia resembles 

 Yentriculites in ■ the simple hollow cavity of its fibre and the non- 

 spiculate character of its skeleton ; Darwinella offers a resemblance 

 in its hexaradiate horny spicules, and Spongionella in the regular 

 arrangement of its fibres. These three genera are indices of the 

 directions in which the Keratosa tended to vary. At a very early 

 period great variation occurred among the Keratosa, which already, 

 at the time of the "Weisse Jura, had evolved such highly symmetrical 

 specialized forms as the Yentriculites. These, with their contemporary 

 variations, such as Yerongioid forms, lived on in great numbers 

 throughout the Mesozoic period, with the close of which the Yentri- 

 culites altogether disappeared ; while their nearest allies dwindled 

 down to the dwarfed and rare genera Verongia, Darvjinella, and 

 perhaps Spongionella. 



LXI. Intelligence and Miscellaneous Articles. 



AMERICAN ASTRONOMY. 



A PPEXDlX IY. of the 'Washington Observations' for 1871 

 ** contains a most interesting account of the Pounding and Pro- 

 gress of the United-States ISaval Observatory by Professor bourse, 

 hi which the earliest steps taken towards the establishment of an ob- 

 servatory, the difficulties encountered during a period of forty years 

 in carrying out the design, the meteorological work under the super- 

 intendence of the late Commander Maury from 1844 to 1861, the 

 devotion of the capabilities of the establishment to purely astronc- 



