M. K. A. Zittel on Fossil Calcispongim. 127 



spongia, D'Orbigny understood chiefly certain Stromatoporev 

 furnished with pores, as well as some calcareous sponges from 

 the Upper Cretaceous, which were placed by Fromentel under 

 Trernospongia. Of all the species of Sparsispongia, mentioned 

 in the " Prodrome," not a single one belongs to the present 

 genus, whilst our diagnosis of Sestrostomella embraces most 

 of the Sparsispongia) and a part of the Tremospongice of Fro- 

 mentel. Fromentel distinguishes these two genera principally 

 according to the absence or presence of an epitheca. But that 

 so unessential and inconstant a character cannot be employed 

 for the discrimination of genera among the sponges any more 

 than among corals, is most clearly seen in the fossil Calci- 

 spongiffi, among which, on account of this difference, we 

 should have to place in different genera forms which agree 

 perfectly in all other essential characters. 



As Fromentel has applied D'Orbigny's names Trernospongia 

 and Sparsispongia quite arbitrarily, and D'Orbigny himself 

 characterizes them by very indefinite and, in part, erroneous 

 diagnoses, I regard it as advisable to drop both names. 



The genus Sestrostomella occurs from the Trias up to the 

 Cretaceous. 



a. From the Trias. 



1. Palccojerea gracilis , Laube, St. Cass. Taf. i. fig. 4. 



2. Sestrostomella robusta, Zitt. 



Epeudea sp., Loretz, Zeitschr. cleutsch. geol. Gesellsch. 1875, p. 832. 



b. From the Jura. 



1. Jerea biceps, Reuss, Denkschr. Akad. Wiss. Wien, xxvii. 

 Sep. Abz. Taf. ii. %._ 9. 



2. Spongites (Nadispongia) cribratics, Quenst. Petr. Taf. 

 exxv. figs. 14-18. 



c. Front the Cretaceous. 



1. Sparsispongia Jlabellata, From. Cat. Rais. pi. iii. fig. G. 



2. Sparsisjyongia varians, From. ib. pi. iii. fig. 8. 



3. Trernospongia bullata, From. Introd. pi. iv. fig. 10. 



4. Sparsispongia sulcata, Loriol, Et. Val. Arz. pi. ix. 

 fig. 4. 



5. Sparsispongia gemmata, Lor. ib. pi. ix. figs. 5-7. 



6. Trernospongia valanginiensis, Lor. ib. pi. ix. fig. 1. 



7. Trernospongia divaricata, Lor. ib. pi. ix. fig. 2. 



8. Sparsispongia brevicauda, Lor. Urg. Land. pi. v. 

 figs. 19-21, pi. vi. fig. 8. 



9. Sparsispongia abnormis, Lor. ib. pi. vi. figs. 3-6. 



10. Sparsispongia expansa, Lor. ib. pi. vi. fig. 7. 



