800 W. J. SOLLAS ON THE STRUCTURE AND 



1852. D'Orbigny. ' Cours clem, do Faleontologie et Ge'ologie/ 

 torn. ii. p. 212, fig. 336. 



The sponges are here divided into two groups, those " a squclettc 

 corne " and those " a squelette testace; " the latter, characterized by 

 a stony calcareous skeleton, are wholly fossil and extinct, the former 

 recent and never found in the fossil state. Our Siphonia, therefore, 

 along with all other fossil sponges, belongs to the testaceous division, 

 and, with six other genera, it constitutes the family " Siphonidae." 



The figure of S.Jicus (fig. 330), so often quoted as D'Orbigny's is 

 adopted without acknowledgment from Sowerby's beautiful drawings 

 of IS. jpyriformis. 



1853. Mantell, G. A. ' Medals of Creation,' p. 230. 



A short account of the genus and some of its characteristic 

 species is given, accompanied by woodcuts (lign. 73. figs. 1 to 5). 

 A form very similar to S. pyriformis is said to occur somewhat 

 abundantly in the Portland limestone ; this confirms Goldfuss's 

 observation on the range of this species. 



A new species, Siphonia Morrisiana (lign. 69. fig. 3), is next 

 described from slices commonly used at Brighton and in the Isle of 

 "Wight for mounting in brooches ; but no evidence is produced to 

 show whether this is a Siphonia or not. 



Choanites Kbnigii (lign. 75) is again described, and said to differ 

 from Siphonia in the absence of a stem. The spiral tube which 

 was detected by Mr. Cunnington winding round its central cavity, 

 is stated to be inconstant. 



1854. Morris, John. ' Catalogue of British Fossils,'" p. 30. 



The species of Siphonia recognized by Professor Morris as occur- 

 ing in Britain are as follows : — S. anguilla, Lee ; cervicornis?, Goldf.; 

 clava, Lee; costata, Lamx. ; Morrisii (Morrisiana, Mantell); pyri- 

 formis, Goldf.; terebrata (Spongia terebrata, Phillips); Websteri, Sow. 



1857. Pictet, F. G. ' Traite de Paleontologie,' torn. iv. p. 541, 

 Atlas, pi. ex. figs. 15, a, b, c. 



Follows D'Orbigny in his views of the structure and relations of 

 Siphonia, adopting D'Orbigny's tribe of Siphonidac, and placing this 

 along with all other fossil sponges except Clionides, i. e. boring 

 sponges, in his family Petrospoxgidjs, which corresponds with 

 D'Orbigny's "sponges with testaceous skeletons," minus the Clionides 

 before mentioned. 



In addition to Hallirhoa, PoJi/pothecia and Choanites are included 

 as synonyms. 



1859. Fromentel. " Introduction a 1' etude des Eponges fossiles ; " 

 extrait des Mem. Soc. Linn, de la Gorman die, vol. xi. pi. i. f. 12 

 et 12 a. 



The order " Spongitaircs " of this author corresponds to Pictet's 

 Pctrospongidoe ; and his suborder of Spongitaria tubidosa embraces the 



