THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTOEY. 



[FIFTH SERIES.] 



No. 8. AUGUST 1878. 



XIII. — Studies on Fossil Sponges. — II. Lithistidce. 

 By Kakl Alfred Zittel *. 



[Plate VIII.] 



A. Generalities. 



Since the publication of the first section of these "Studies" 

 (see ' Annals/ ser 4, vol. xx.) the literature of fossil sponges 

 has been enriched by a work of great importance. The first 

 three parts of the fifth volume of F. A. Quenstedt's ' Petrefac- 

 tenkunde Deutschlands ' have appeared. These treat exclu- 

 sively of fossil sponges. In sixteen folio plates the asto- 

 nishing abundance of marine sponges in the White Jura of 

 Swabia and Franconia is made manifest ; and the figures in 

 truth to nature and accuracy are certainly unsurpassed. Un- 

 fortunately Professor Quenstedt has disdained to pay any 

 attention to the histological characters. Structural conditions 

 are only referred to so far as they can be recognized with the 

 lens ; and thus the zoological value of this important work is 

 essentially diminished. In the grouping of the different 

 forms, geological occurrence and general habit are taken into 

 consideration in the first place ; a systematic treatment of the 

 material in a zoological sense is, as a matter of course, not 



* Translated by W. S. Dallas, F.L.S., from a separate impression 

 communicated by the author, of his paper in the ' Abnandlungen der k. 

 bayer. Akad. der Wiss.' II. Classe, Bd. xiii. Abth. i. pp. 67-154. The 

 original memoir is accompanied by ten plates, from which some figures 

 will be used, where necessary, for the illustration of this translation. 



Ann. & Mag. N, Hist. Ser. 5. Vol. ii. 8 



