136 



Hevieu's — Br. G. J. Hinders Fossil Sponges. 



The following is a summary of Dr. Hinde's tabular list of species 

 arranged in zoological sequence (see pp. 212-222) : — 





i 

 g 



8 

 6 



17 

 8 



5 

 21 



2 

 9 

 4 

 I 

 11 

 13 

 6 

 5 

 I 



2 



2 



I 

 I 



26 



I 



1 



Q. 



tn 



II 

 12 



50 

 14 



6^ 



6 



25 

 8 



I 



20 

 22 



6 

 6 



3 



8 



I 

 I 



105 

 1 



1 

 399 



1 



u 



I 



I 



c 

 "> 



■a 

 



I 



_3 



55 



I 



"i 



6 



2 

 2 



1 



> 



Q 



I 



I 



3 

 



'5 

 .0 



u 



2 

 2 



I 



! ■•• 



16 

 , 16 



1 



>-. 



I 



17 

 I 

 2 



13 



7 

 10 



I 



42 



I 



I 

 "96 



3 





Division I. 

 Siliceous Sponges. 



Order MoNACTiNELLiD^, Zittel 



„ Tetractinellid.e, Marshall... 



„ L1THISTID.E:, 0. Schmidt 



Fam. Rhizomorina, Zittel 



4 

 10 



33 

 12 

 2 



59 



II 

 8 



I 



25 



6 

 21 

 6 

 6 



I 

 I 



47 

 254 



2 

 2 



„ Megamorina, Zittel 



,, Anomocladina, Zittel 



,, Tetracladina, Zittel.... 



Order HEXACTiNhLLiD^,,0. Schmidt. 

 Sub-ord. Dictyonina, Zittel 





„ Euretidae, Zittel 





„ Mellitionida?, Zittel 



„ Ventriculitidas, Zittel 



„ Staurodermidae, Zittel 



„ Meandrospongidae, Zittel 



„ Coeloptychidae, Zittel 





Fam. Monakidas, Marshall 





I 



„ Pollakidas, Marshall 



2 

 3 



1 

 14 





5 



I 



Incerice sedis. 



Mortiera vertebralis, de Koninck ... 



Division II. 



Calcarkous Sponges. 



Order Calcispongi^, Hlainv 



Fam. Pharetrones, Zittel ... 



„ Sycones, Haeckel 



Incertce sedis. 

 Bactronella pusillum, Hinde 





2 II 



It thus appears that out of a total of 399 species described, there 

 are 292 or about 73 per cent, of siliceous sponges, and 107 or 27 per 

 cent, of calcareous forms. The geological distribution of the group 

 presents some peculiar features. From the Palseozoic rocks only 31 

 species of siliceous sponges are recorded, and whilst all the diiferent 

 orders of siliceous sponges are represented, the large majority of the 

 forms belongs to the order of the Hexactinellidee, which is generally 

 regarded as the most highly organized division of the Spongidee. 

 From the Mesozoic strata, 366 species, or more than nine-tenths of 

 the entire collection, are described, and of these no fewer than 254. 

 species have been derived from the Cretaceous system ; whilst 96 

 species are from the Jurassic and 16 (all calcareous) from the 

 Triassic. Only two species are noted from Tertiary strata, but it 

 must not be supposed that this insignificant number fairly represents 

 the Sponge-life of this era, since numerous forms have in the last 

 few years been discovered in beds of Miocene- age in Italy and 

 Algiers, though specimens have not yet found their way into the 

 Museum collection. 



